Mapei additives

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HEAD OFFICEMapei SpAVia Cafi ero, 22 - 20158 MilanTel. +39 02 37673.1Fax +39 02 37673.214Internet: www.mapei.comE-mail: [email protected]

CEMENT GRINDINGADDITIVES DIVISION

CEMENT GRINDING ADDITIVES DIVISION


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THE WORLD OF MAPEI 2

LIQUID ADMIXTURE DIVISION 6

CEMENT GRINDING ADDITIVES DIVISION 8

TECHNICAL BACKGROUND OF MAPEI GRINDING AIDS 10

A BRIEF OUTLINE OF AN ANALYSIS OF THE SEPARATION PROCESS 22

PRODUCTS 37

MA.G.A./C Technical Data Sheet 39

Industrial Trial with MA.G.A./C1 41

Industrial Trial with MA.G.A./C2 51

MA.G.A./M Technical Data Sheet 61

MA.P.E./S Technical Data Sheet 63

Industrial Trial with MA.P.E./S 65

MA.P.E./W Technical Data Sheet 77

Industrial Trial with MA.P.E./W1 79

MA.P.E./A Technical Data Sheet 89

MA.P.E./Cr 05 Technical Data Sheet 91

Scientific Background 94

Industrial Trial with MA.P.E./Cr 05 100

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I N D E X

The World of Mapei

Founded in Milan in 1937, Mapei istoday’s world leader in theproduction of adhesives andchemical products for building.

Starting in the 1960’s Mapei put itsstrategy of internationalization intoaction in order to have maximumproximity to the needs of localmarkets and reduction of shippingcosts to a minimum.

The Group now counts 57subsidiaries with 54 productionfacilities in operation in the 5continents in 24 different countries.

Furthermore, Mapei has developeda sales and technical servicenetwork with offices all over theworld and offers an efficient

Technical Assistance Service that ismuch appreciated by architects,engineers, contractors and owners.

Group HeadquartersMapei S.p.A.viale Jenner, 4 Milan - Italy

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TO BE OUR CUSTOMERS’ BEST SUPPLIERWe offer our services as a business partner and we are highly committed to provide our customers solutions with a high added value.

TO BUILD A PARTNERSHIP WITH OUR STRATEGIC SUPPLIERSWe are committed to ensuring that our strategic suppliers turn meeting our needs into an opportunity to jointly design new products and solutions which can also cater for the latest market requirements.

TO ALWAYS KEEP ONE STEP AHEAD We try to anticipate designers’ requirements and interpret business and building-site needs.

TO BUILD A WINNING AND COMMITTED TEAMOur most precious resource is the value of our team: we work together passionately and grow professionally thanks to constant training.

TO ALWAYS TELL THE TRUTHA high-profile and transparent communication strategy allows us to convey and share our values with as many people as possible.

TO IMPROVE ALL OUR PROCEDURES BY MEANS OF QUALITY CONTROLAAll our products and services conform to the highest ISO 9001 certified standards.

TO BE AT THE CUTTING-EDGE IN TERMS OF ENVIRONMENTAL SAFETY AND HEALTHWe attach great importance to the environmental sustainability of our products, the eco-friendly nature of our procedures and the safety of our customers, workmates and entire community.

TO INNOVATE CONSTANTLY Every year we strategically invest more than 5% of our overall turnover in Research & Development.

TO BE DETERMINED TO ACHIEVE EXCELLENCEWe strive to achieve ambitious goals so that we are market leaders in our chosen sectors.

TO MAINTAIN SOLID FINANCIAL FOUNDATIONSSo that we can invest in the technology and products of the future.

THE 10 PILLARS OF OUR SUCCESS

Mapei has always placed greatemphasis on research. So much so, infact, that 5% of its turnover is investedin Research & Development and 70% ofits R&D efforts are directed to developeco-sustainable and environmentfriendly products which meet LEEDrequirements. Mapei boasts eight mainresearch centres: three in Italy (Milan,Villadossola and Treviso), one in Canada(Laval), one in the United States (DeerfieldBeach), one in France (Toulouse), one inNorway (Sagstua) and one in Germany(Wiesbaden). Research staff make upapproximately 12% of the company’stotal workforce. The Milan ResearchCentre is the biggest, in terms of staff,

and also co-ordinates the work of theother seven laboratories. In addition, itacts as a central analytical laboratory forthe whole group. Mapei recruits morenew employees in research than in anyother area, with priority given tograduates and other qualified students.The laboratories are equipped withavant-garde equipment and work inclose contact both with each other andwith universities and other scientific andindustrial research institutions. They alsoprovide back-up technical assistance tohelp solve customers’ most complexproblems. There are further qualitycontrol laboratories in all of the Group’s54 factories.

Mapei has always devoted a lot of effort to research. 5% of turnover are allocated to investments in this field of activity. 12% of Mapei employees work in research.

Our commitment for the environmentMore than 150 MAPEI products,featuring the “Green innovation” mark,help to contribute valuable pointstoward LEED-certified projects.

Research and Development

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T H E W O R L D O F M A P E I

2008. ROBBIANODI MEDIGLIA (MILAN)In the picture, the main manufacturing plant of the 54 facilities of the MapeiGroup. In 2008 theexpansion project ofRobbiano di Mediglia plant is still ongoing with the new wall finishing production line.

Bridge overthe River Danube,Hungary

Liquid Admixtured Division

CEMENT GRINDINGADDITIVES

more energy efficiency

less clinker and CO²

CEMENT GRINDINGADDITIVES

more energy efficiency

less clinker and CO²

CONCRETEADMIXTURES

more durability

less non-renewable raw material

UNDERGROUNDTECHNOLOGY TEAM

more durability, safety and energy efficiency

less non-renewable raw materials

HPSS*SYSTEM

more respect for the environment and health

less waste material

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Integrated solutions for the cement-concrete sector, for lowerconsumption of non-renewable raw materials, to reduce CO2 emissions and increase the service life of structures.

* HPSS System High Performance SolidificationSystem for treating contaminated ground and sediments

ttttttCement Grinding Additives Division

CEMENT GRINDING ADDITIVES DIVISIONFounded in 2000, D.A.M.(Divisione Additivi diMacinazione) has grown anastonishing 30% every year interms of turnover and volume,thanks to innovative and high-quality products combined withtechnical support anddedicated Research andDevelopment. Today, supported by thegroup’s structure and expertise,D.A.M. is supplying all majorcement groups worldwide,offering new technologies andlocal technical assistance. By combining high quality rawmaterials, fully computer-basedproduction facilities andspecific expertise in terms ofproduct chemistry, industrialemployment and grinding planttechnology, D.A.M. is able toguarantee high levels ofcustomer assistance andproduct quality.

R&DBy investing over 5% of itsturnover and 12% of its HumanResources in Research andDevelopment, the Mapei Grouphas become market leader interms of innovation. Thededicated D.A.M. scientists at Mapei’s Research Centresnot only develop new rawmaterials and grinding aidcomponents, but are alsoactive in customer support. Infact, Mapei’s state of the artlaboratories allow D.A.M. toperform specific and in-depthclinker and cement analysis in order to optimise the use of Grinding Aids and to offer customized solutionsfor cement performanceenhancement and productionimprovement.

ECO-SUSTAINABILITY Mapei grinding admixturesform a system of innovativesolutions for cement works;they allow a reduction in clinkerwhile offering the samemechanical performance ofcement, thus guaranteeing areduction of 5-10% in CO2

emissions and a saving in non-renewable raw materials.

TAG TEAM (Technical AssistanceGroup)A team of experienced processengineers from the cementindustry joined D.A.M. in orderto provide specific technicalassistance to D.A.M. customers.By performing complete plantaudits and by analysing thegrinding circuit’s performance,they are able to assist D.A.M. customers with theimplementation of Grinding Aidsand to optimise the grindingprocess in all its aspects.

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Please contact us dircetly for specific product selection, assistance and technical documentation.

Our Products

ProductGroup Description

TypicalDosage

Production Increase*

StrengthIncrease* Workability* Air

Entrainment*Cr(VI)

reduction*Typical

ApplicationCO2

Reduction

MA.G.A./C

Highly concentrated, high performance

grinding aids, suitable for grinding

of all cements.

200 - 400 g/t AllCements

MA.G.A./M

Highly concentrated, high performance

grinding aids, particularly

suitable for grinding of minerals.

300 - 600 g/tMinerals and Raw Materials

MA.P.E./S

Grinding aids, strength improvers, specifically

formulated for grinding of blended

cements (pozzolanic, blast-furnace slag

and fly- ash cements).

1000 - 2000 g/t Blended Cements

MA.P.E./W

Grinding aids, strengths and workability (flow) improvers, specifically formulated for grinding

of blended cements (pozzolanic, blast-furnaceslag and fly- ash cements).

1000 - 2000 g/t Blended Cements

MA.P.E./A

Additives formulated for grinding

of masonry cements (Air Entrainment).

400 - 800 g/t Masonry Cements

MA.P.E./Cr Specific additives for Cr(VI) reduction. 50 g/t ppm All

Cements

* at typical Dosage

Possible Recommended Highly Recommended

Technicalbackground of Mapei Grinding Aids

1. THE AGGLOMERATION PHENOMENADuring the grinding process, the increase rate in the specific surface proportionally decreaseswith the fineness increase. Rittinger’s law demonstrated that there is a direct proportionalitywithin the grinding time and specific surface till a precise fineness (depending on the material andthe grinding system). Beyond this fineness the real curve diverges from the theoric one, and thereis no more direct proportionality between grinding time (energy) and produced specific surface.In practice, it is not possible to exceed some fineness values, not even by extending the grindingtime. This is principally caused by the particles agglomeration that drastically reduces the pro-cess performance. The cement particles agglomeration acts on the grinding and on the mill liningas an abrasion resistant film, but also as fine particles, already grinded, agglomerated by electro-static forces and local conditions of pressure and temperature. It is easy to understand how thefilm and particles agglomerates can reduce the mill balls effect, by absorbing bumps and disper-sing the energy needed for the particles comminution.

The agglomeration phenomena entity depends on:• material type (chemical composition, crystalline structure);• Grinding fineness;• mill type (ball mill, vertical mill etc.);• grinding system: open or closed circuit;• balls and lining conditions;• temperature, humidity, ventilation etc. inside the mill.

2. MECHANISM OF ACTION OF THE CEMENT ADDITIVESGrinding aids have been widely used for more than 50 years. It is also well known that their mainaim is to prevent cement particle agglomeration during the milling process. As a consequence theyreduce mill retention time and improve separation efficiency, which decrease energy consumptionof the plant while maintaining constant the quality and quantity of the cement produced.Cement additives improve mechanical strengths by producing a narrower cement particle sizedistribution, which at the same time is shifted toward smaller diameters (Figure 1).

Figure 1

Ø (MA.GA./C 100) = 28,70 µm

Particle Size Analysis

Ø (blank) = 31,50 µm

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While all that we have said up to now is evidence of cement additive use which has allowed theirdiffusion, their real action mechanism in the hydration of cement is not completely understoodyet. What is not yet clear are the actual chemical-physical interactions they have with cement,which give it all the properties and advantages already mentioned above.The more accepted thesis is that the grinding aids act to reduce the surface energy forces gene-rated on cement grains during comminution. They are composed of polar organic compounds,which arrange their dipoles so that they saturate the charges on the newly formed particle surfa-ces of the clinker, reducing agglomeration (Figure 2).

This theory stems from the fact that water, itself a polar molecule, has been considered to be agrinding aid, but deemed less efficient due to its low screening effect. However, this theory doesnot fully explain the fact that an additive is effective even at very low dosages (< 500 ppm) con-sidered insufficient for a complete covering of the cement particle surface which would be neces-sary for the “free charges” screening theory to be the only explanation. Since no exhaustive evidence has been found that this is the unique mechanism, research in thisfield is still going on, making use of the most sophisticated and modern technologies, trying tofind an appropriate answer to this problem.Various research groups have followed distinct approaches, such as analysis of the sample addi-tive extracted from cement after grinding, morphological analysis of the cement paste after addi-tion, evaluation of the relationship between additive effects on mechanical strengths and cementmineralogical composition.Since 2000 MAPEI R&D laboratories have also concentrated their efforts on this subject, with theobjective of formulating high performance cement additives, which can satisfy client expectations.Our approach has been as much multidisciplinary as possible with the aim of look at all aspectsof this complex subject. To do this, we have used some of the most updated analytical techni-ques such as:

Figure 2

Figure 3

a(0 mins)

b(5 mins)

c(60 mins)

d(420 mins)

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Since the first gel forms within a few seconds and covers completely the cement grain, it actual-ly represents the grain surface. Then water and any substances added to the cement, working asan admixture, must interact with this gel.This means that during the milling process of the cement, which is usually carried out in presen-ce of water and grinding aids, conditions exist for the electrostatic charges dispersion discussedbefore, but most of all for a preliminary hydration of the clinker. Once the clinker powder produced is then mixed with water, we observe the formation of a gel,whose structure is drastically different when grinding aids, such as MA.G.A. / C, are used duringthe milling process (Figure 4).

These preliminary investigations suggest that the cement maintains a “memory” of the kind ofmanufacturing process.

3. BENEFITS OF GRINDING AIDSGrinding aids (GA) are principally employed for mill output increase at the same specific surface(specific energy saving). The main benefits of GA are the following:

• Increase in output at the same fineness. Output increase reduces specific energy costs. Theincrease in production could be used to cover market demand (increased sales), to reduce pro-duction costs (grinding during lower energy cost periods) and to reduce maintenance costs.• Fineness increase at equal output, or both effects. In some cases very high fineness may onlybe obtained by using GA. Fineness increase at equivalent specific consumption allows improve-ment of the final product performances (e.g. cement strengths).• Improved granulometric particle distribution curve at equal fineness. In case of two cementsgrinded at the same Blaine specific surface, the one grinded with GA has higher mechanicalstrengths thanks to a more compact granulometric particle distribution curve obtained through theelimination of the finest and coarse particles.

Figure 4

Clinker hydration (10 mins) Clinker hydration (10 minutes) ground with MA.G.A./C

T E C H N I C A L B A C K G R O U N DO F M A P E I G R I N D I N G A I D S

• Lower grinding media consumption.• Higher separator efficiency. When agglomeration occurs a particle agglomerate would be seenas a coarse particle and swept out by the separator. With the addition of MA.G.A./C the particlesare separated and passed as fine particles suitable for the final product.• Improved flow characteristic of the cement during transport, silo storage and duringloading/unloading operations. Reduction of silo clogging, that usually results in reduced silos volu-me and extraordinary repairs costs.

4. QUALITY IMPROVERS/PERFORMANCE ENHANCERSEven if the pure grinding aids could be considered as grinding products which somehow improvethe quality of the finished material (ex. calcium carbonate with better granulometry and/or withbetter flow) it is necessary to distinguish them from the pure quality improvers, that are tailor-madeformulations, and for which it is advisable to consult with the Cement Additives Division techni-cians.

4.1 Cement additivesCement performances are principally characterized by mechanical strengths, water demand andsetting times. MAPEI has formulated additives focused on improving each single characteristic,while at the same time maintaining a strong grinding effect.• Mechanical strengths. The UNI ENV 197-1 sets out the mechanical strengths required for eachcement class. The reasons why mechanical strengths (at early and ultimate ages) could be impro-ved are the following:- technical (insufficient strengths)- commercial (competition on the market)- economical (decrease in clinker additions, changing the cement composition etc.)• Water demand. For certain types of cement (usually pozzolanic and fly-ashes cements) it isimportant to control the flow values and modify them on end-users requests. There are specificadditives especially formulated to solve this problem, and that do not interfere with concreteadmixtures.• Initial/final setting time. Special additives work on initial and final setting time, offering a cementadapted to local temperature or to the season. Usually the capacity of the additive to modify thesetting times is an additional option, and its principal aim is as a grinding aid or strengths impro-vement.

4.2 Air entrainers for hydraulic masonry cementsArtificial hydraulic masonry cement is obtained with the addition of 15-40% of clinker, and is cha-racterized by good mechanical strengths, but lower workability than the natural one. The MA.P.E./Agive to artificial hydraulic masonry cements characteristics similar to the natural ones (workabilityand durability). They also improve entrapped air and water retention. Air is entrained in micro-bub-bles, homogeneously distributed, that improve cement workability, yield per surface unit and resi-stance to freeze-thaw cycles.Water retention improves adhesiveness by avoiding cracking.

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4.3 Pack-set inhibitors for mineralsPack-set inhibitors are added during the dry minerals grinding process to obtain output increaseor high fineness. In case of calcium carbonate the additives must improve the flow characteristicsof the grinded material. For this reason specific products have been formulated, and are apprecia-ted as much for their dispersing properties as for their grinding aid characteristics. MA.G.A./M GAare available to satisfy various requirements, and tailor-made formulations can be studied by ourDivision.

5. GRINDING AIDS EVALUATIONThe evaluation of grinding aids has to include both technical and economical considerations. Thetechnical evaluation follows a reliable industrial trial, performed after preliminary lab tests. The eco-nomical evaluation, to be preferably performed after the technical one, has to consider several fac-tors that are not always easily quantified in terms of money.

5.1 Technical evaluation: industrial trials with grinding aidsIndustrial evaluation of GA is necessary to verify their real obtainable performances. For this rea-son a reliable industrial trial has to be carried out for a right evaluation of the product. A reliableindustrial trial must reduce to the minimum the quality differences of the raw materials used forthe cement production. Our suggestion is to grind for 2 weeks – 1 month, in order to compare theaverage results obtained in a similar control period immediately before the industrial trial.We hereby summarize the most important points that the Cement Additives Division suggests tofollow during an industrial evaluation of the additives, specifically referring to the cement.• Only a reliable industrial trial performed for a long time can assure reliable results; our policy isto carry out a long period test and to render technical assistance during the trial.• A reliable industrial trial must be carried out under normal and regular production cycles.• A long-period trial allows results to be obtained that are not affected by the normal variations ofthe clinker, lime or other added materials.• Each MAPEI additive has been completely tested in the lab, but the industrial trial is alwaysnecessary to define the real additive performance on the cement.• At the beginning of each trial, it is necessary to precisely define the plant working conditions withor without the additive to be tested.• It is important to define a sampling plan; it is advisable to divide the samples for the planned labtests to be performed both by the cement plant and Mapei laboratories.• To optimize the results, a co-operation between plant technicians and Mapei consultant is advi-sable. At the end of the trial, we suggest a meeting in order to work on the same results.• At the end of the industrial trial, Mapei technicians will write a complete technical report to besent to the cement plant.

5.2 Economic evaluationThe most apparent effects of a grinding aids are output increase and energy saving, that could beeasily evaluated in terms of money. The other benefits are not so easily estimated, though some-times they are more conspicuous than the energy saving.


The following formula quantifies the energy saving in terms of money S[€/t]:

Where: [€/t]

- P mill output without additive [t/h]- α mill output increase [%]- Ke total energy costs (absorbed kWh * cost kWh) [€]- Ka additive cost (cost per kg * dosage) [€/t]

This formula calculates the saving per ton of ground material, in the cases where:- Output increase at equivalent energy consumption;- Fixed energy cost, at all times of the day;- Product with similar quality to the previous one (without additive);- Additive dosage calculated on the initial mill output (most common case).

When the dosage is calculated on the new mill output, the formula is modified as follows:

In practice, with the above calculation of the economical advantages, other several factors are notconsidered; they have to be evaluated case by case and are always more difficult to estimate. Wehereby summarize the principal elements to be considered for a correct and complete estimation.It has to be noted that, while the energy saving is always considered, other advantages depend onthe process conditions and should be evaluated to each specific situation.

5.3 Production benefits• Mill output increase: more material available to increase sales.• Grinding during low energy cost periods: lower average cost per unit of energy.• Better management of peak market demands, due to increased production capacity. The addi-tive could be considered as a flexible production tool, even though not constituting a structuralinvestment.

5.4 Quality benefits• Cement performance improvement; greater competitive position on the market;• Production of the same cement by decreasing the clinker percentage, with a saving in produc-tion costs.

5.5 Maintenance benefits• A higher production per hour allows more time for preventive maintenance interventions, avoi-ding urgent maintenance that is always more expensive.• Better flow characteristic of the cement during transport and in silos, with a significant reductionof the plant stops and maintenance costs.

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6. ADDITIVE SELECTIONThe grinding aid is liquid, and has to be dosed through a metering pump, onto the conveyor beltor directly in the first chamber of the mill.

6.1 Dosage systemThe simplest system is a manually regulated pump, installed soon after the other material measu-rers, at the mill entrance. When the mill is operating under standard conditions, the additive isdosed at a fixed flow rate, and does not alter in line with production variations. It is a very efficientsystem, but has no flexibility and has to be strictly controlled by the operators.In modern plants, the flow rate depends on the real mill output, and the additive is dosed by a flowgauge that controls the pump through a computer. In this way the additive is treated as one of theother components to be added in the mill, by indicating its percentage in the cement composition.

6.2 Metering pumpsPlunger or diaphragm metering pumps can be used. Plunger metering pumps (with steel plungerand pump head) are largely used, due to their low cost. Diaphragm pumps are more sophisticatedand their benefit is that the plunger is not in direct contact with the additive. They can also suckviscous additives and are not damaged by impurities sucked from the bottom of the tank. In orderto optimize the additive dispersion (especially for low dosage additives) our suggestion is to installa double headed pump: the first head for the GA, and the second one for water, with anadditive/water ratio of 1:2 or 1:3. It is advisable to install a cartridge filter between the additive tankand the pump, in order to prolong its functional lifetime.

6.3 Additive dosage onto the conveyor beltThis is the simplest system and allows a direct visual control of the flow. The additive must not wetthe conveyor, to avoid crusts whose thickness may enlarge on the return and support rolls. Themost frequent problems are caused by high dosage additives (0.2-0.3%) and on quick conveyorbelt (with a low material layer): in this case is necessary to use a rake to better distribute the addi-tive and avoid drops falling onto the bare belt.


6.4 Additive dosage into the first chamber of the millThis is the “cleanest” dosage system, but it has to be carefully controlled to avoid problems. It isadvisable to install a metal lance with two coaxial tubes: the additive will flow inside, and the out-side support air will be supplied by a fan. The additive tube must extend 1 cm more than the airtube, to allow any possible drops to fall on the material. The fan has to work for a certain periodafter each mill stop, to avoid the obstruction of the additive nozzle by the powder in suspension.It is also advisable to position a T tap before the mill entrance, in order to manually measure theadditive flow.

30 m3 30 m3

Regulation

30 m3 30 m3

Regulation

Mill output

Mill output

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ADDITIVE LANCE SCHEME

1. Position of the lance relative to the mill

2. Lance profile and section

ST


6.5 Pump installation

Installation1. Secure the pump to a horizontal support2. Control that the oil level for the lubrification of the gears is ok3. Protect the pump from liquids and powder4. Leave enough free space around the pump for maintenance operations and adjustments.

Typical scheme of installation in the plant1. Low positive pressure in suction, hsuc

2. Higher positive pressure in discharge, h.>hdisc

3. Short and linear suction circuit4. Suction and discharge circuits section pump connection section

100 mm

100 mm

80 mm

150 mm

Fig. 1

Fig. 2

hdisc

hsuc

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In the cement plants the simple scheme below is used to dose the additives, considering that theyare dosed at low pressure and room temperature. For a more complete dosage system the follo-wing components could be installed:

Suction circuita. Realise a short and linear circuit, with tube diameter of about 1.5 times the pump nozzles. Themax flow rate per single piston pump is 3,14 times more than the average one.b. Install a permanent filter (1) in front of the pump in an easily accessible place, with 150 µmmeshes.c. In case of long tubing, install a damper (2) beside the nozzle, in order to avoid the phenomenaof cavitation.d. Avoid connecting the pump to the tank bottom, to avoid the suction of potential impurities.e. Install a shut-off valve (3) for the disassembly of the pump when the lines are full.

Discharge circuitf. Realize the circuit with tubes with diameter wider than or similar to the one of the pump nozzle.g. It is advisable to maintain between suction and discharge a positive difference of pressure (40– 100 KPa), as per fig. 2. If this is not possible due to the position of the tank and of the dischar-ge circuit, (ex. tank positioned higher than the suction circuit) it is possible to install a back pres-sure valve (5).h. Soon after the pump it is advisable to install a calibrated safety valve (4), with a visible and opendischarge.i. To regulate the liquid flow it is advisable to install a pulsation damper (with direct contact or witha dry diaphragm), soon after the pump discharge valve. In case of installation of a back pressurevalve, it is better to position the damper after the valve.j. In case of installation of a flow regulator (mechanical or inductive) (6), it is advisable to install a fil-ter before the flow regulator.k. A check valve should be installed for the possible disassembly of the pump when the lines are full.


Amongst the large range of installations schemes of closed grinding circuits, which could inclu-de one or more separators, we will consider and study the classic disposition represented in Fig.1 where one mill and one dynamic separator are used.

In the above scheme the machines operational systems are well defined.The mill has a comminution function that, from a starting particle size distribution, creates newand smaller cement particles and subsequently new specific surface.From the particle size distribution supplied by the mill it is possible to produce a new product withrequested specific surface through a separator: the residue is automatically sent back to the millfor further grinding.In a closed circuit the separator increases the working value of the principal system: the mill.

1. EVALUATION OF A CLOSED CIRCUIT GRINDING SYSTEM1.1 Circulation coefficientIn practice there are several systems for the evaluation of a plant working in a closed circuit; themost immediate one seems to be the “circulation coefficient”, expressed by the ratio F/P (sep.feed material/final product). It is a general opinion that a high circulation rate means a “poor fun-ction” of the separation and vice versa; this could be true but the concept should not be genera-lised.In fact the final product could only be evaluated from the particle size distribution obtained withthe mill; if the final product is “big” the separator could only extract a fine product by refusing asignificant amount of coarse material, resulting then in a higher circulating load. The circulation coefficient could then be considered as a quality index of the functioning of thecomplete system, and not only of the separator.It is useful to precise that the circulation coefficient A/F (circulating load) is also based on the mill

A brief outline of an analysis of the separation process

Fig. 1

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dimensions, and depends on the L/D ratio. It is then logical that with short mills, the circulatingcharge F/P has to be proportionally higher. In practice the circulating load represents an artificialextension of the mill, that is to say a uniformity of permanence time of the material in the mill, withrespect to other L/D ratios.

1.2 Separator precisionSeveral methods have been proposed for the evaluation of the precision or performance of aseparation process.In case of separation in two granulometric classes, having decided a separation dimension, andcalled a, g and f the fractions (% in weight) contained respectively in the feeding material, coar-se and final product, the “separator performance” can be defined as the ratio between the “finematerial” contained in the final product and that contained in the feed material.Tab. 2 summarizes the methods normally used in accordance with the VDZ and MT28 standards.The above assumptions have already been criticized, by highlighting the inadequacy of the eva-luation of the functioning of an air separator, due to the influence of the granulometry of the feedmaterial on the results.Furthermore, the choice of a particular separation dimensions, obtained by the above formulas,can be considered as arbitrary, or at least, unjustified.For this reason it is advisable to apply the Tromp curve (or T curve). This function represents thetrend of the separations coefficient rates of the feed material on the coarse and on the final pro-duct, for the several granulometric intervals as a frequency curve on which the separation pro-cess takes place. This should allow for greater precision, irrespective of the feed material’s com-position and of the choice of the separation dimensions.The quantitative evaluation of the above precision depends on some curve parameters; the“separation precision” is defined by the rule VDZ as the rate d35/d65 (being d35 e d65 respecti-vely the granulometries in µm corresponding to a separation degree of 35 % and 65 %); the samerule defined the “separation limit” as the particle dimension of 50% between “large” and “fine”.In practice these parameters are not always applicable due to the fact that, as the curve T isdependent on the A/F rate, the separation curve of many plants is above these distinctive points,and it is thus quite impossible to make a reliable calculation.

Recently other evaluation methods have been studied and proposed by C.E.T.I.C., always deri-ved from the Tromp curve that, though its value is not intrinsic, allows the location of the curvewith precise coefficients, hence allowing calculations to be carried out.

• In practice, following CETIC (that proposes to use the Gaussian coordinates to draw the dia-gram), the curve T is resolved into two lines:

1. the horizontal line, that is the mean of the separation degrees below the ordinate at the abscis-sa point 1 µm (soutirage or by pass);2. a regression line related to the succeeding points on the ascending part of the curve.

We can state the following:a. the “soutirage” or “by pass”, measured from the minimum ordinate (1), represents the materialpassed through the separator without being classified.b. The quality of the “cutting”, defined by the inclination of the ascending part of the T curve; the inclination has also been measured by the “imperfection” value.

TAB. 3 shows in details the drawing system of the T curve following CETIC.

2. COMMENTSWe tried to summarise the different methods applied for the evaluation of the separator functio-ning.We consider it opportune, at this point, to express our considerations on the argument:

• We already criticized the limits of the so-called “performance” (arbitrary choice of the particledimensions, influence of the granulometry of the feeding material, etc.); it is necessary to remem-ber that the above formulas derives from the mineral preparation technique where, generally, it isnecessary to separate the components of a granulometric mix into two fractions. These fractionscould be different one from the other for particle dimensions or chemical composition; in this casea product can contain a material that has not been treated and that has to be separated or recy-cled, or a fine component mixed in a inert mass, that has to be extracted for a further treatment.The formulas represent a concept bound to the results (performance) of a classification; theymeasure the efficiency of the operation in “open cycle” in relation, for example, to the loss of “finematerial” (final product) in the coarse recycled product.In our case, separation in “closed cycle”, the coarse material is re-introduced in the mill for a fur-ther refining and consequently, from the point of view of the preparation of the granulometriccurve for that type of cement, the material to be ground in the mill is already “fine”, with a con-sequent energy saving when compared to a “bigger” granulometry.

• The Tromp curve and related parameters, even though they precisely represents the separationprocess, are affected by the ratio between the loading charge (A) and productivity (F) in such away that is not possible to evaluate the separator, independently from the kind of mill in use. Theseparation coefficients confirms the theoretical deduction that the preciseness of the separation,appearing from the T curve, is higher when the circulation coefficient A/F is lower. Following thisassumption, the performance of the separator is optimal if combined with a long mill, and on thecontrary is worse if combined with a short or very-short mill.

3. CALCULATION EXAMPLESTaking into consideration the limits defined by our assumptions concerning the possibility ofcomparison between two different separators, we hereby report the T curves of some separatorplants, useful for a clear understanding of the above mentioned concepts.

25

The table below summarises the representative parameters (rounded off to significant values):

Some comments:• The separators are of the 1st (Polysius e Smidth) and of the 2nd generation (Wedag): thePolysius TSU has double shafts while the Smidth separator has only one shaft.• The mills L/D ratios ranges between 3 e 3.6, and so are not different one from the other• The loading charges, except from circuit no. 4, are coherent to the mills L/D ratios, even if theyare quite low.

As already anticipated, the "soutirage" value quantifies the material passed through the separa-tor, but that has NOT been classified. It could be defined as a “separation” error.

At this point, the performance of the Wedag separator was good.On the contrary, the performance of the Polysius separator of plant [1] was worse. In fact, with aloading charge of 1.4 (that is quite low, and it is already known the direct correlation within loa-ding charge and soutirage), a by-pass error of 19% has been noted. It has to be taken intoaccount that this is a 1° generation separator.

Always considering the “soutirage”, the separation results of plant [4] would appear really nega-tive; the soutirage error was 66%; however knowing the plant and the separator in use, we candefine that these poor performances are essentially caused by the high fineness of the product,and by the limits of the fineness regulation system of the separator itself.

Concerning the separation “quality”, represented by the inclination of the second branch of theT curve, a substantial equality between all the separators is revealed. The inclinations range bet-ween 20 and 30 degrees. The only exception is the separator of plant [3] which has a higher incli-nation, and hence precision, with a line angle of 46°.

In conclusion, the last observation:Taking into account the limits of our assumption, and also the difficulty of comparison, we deemit useful to highlight the good performance of the Wedag separator which may be judged as relia-ble and competitive even when compared to the latest 3° generation separators.

Mill Loading Separator Soutirage Line CircuitL/D charge inclinationratio A/F type % degrees N°3.6 1.3 Wedag ZUB36 12 31 13.1 1.4 Polysius TSU 19 24 23.3 1.5 Wedag ZUB60 9 46 33.0 3.9 Smidth CV short 66 22 4

A B R I E F O U T L I N E O F A N A N A LY S I S O F T H E S E P A R A T I O N P R O C E S S

blaine

laser

dim.µm f a g df da dg df*F/A dg*G/F A G/A T (%)

2 1.0 16.0 15.0 9.6 16.0 15.0 9.6 12.1 2.32 14.45 0.16 16.05

4 3.0 27.7 25.0 16.8 11.7 10.0 7.2 8.9 1.74 10.61 0.16 16.40

8 6.0 37.4 32.8 21.0 9.7 7.8 4.2 7.4 1.02 8.37 0.12 12.13

16 12.0 49.2 42.3 23.8 11.8 9.5 2.8 8.9 0.68 9.62 0.07 7.03

32 24.0 70.6 60.0 28.5 21.4 17.7 4.7 16.2 1.14 17.36 0.07 6.54

64 48.0 93.9 83.1 50.9 23.3 23.1 22.4 17.7 5.41 23.08 0.23 23.46

128 96.0 99.9 97.9 85.6 6.0 14.8 34.7 4.5 8.39 12.94 0.65 64.83

190 159.0 100.0 100.0 98.8 0.1 2.1 13.2 0.1 3.19 3.27 0.98 97.68

total 494.7 456.1 335.0 Materials in cycle residue [determ. laser / µm]

t/h 30 µm 40 µm 60 µm 90 µm 200 µm

calc. F/A 0.7583 final 42.5

G/F 0.2417 feeding 56.0

coarse 13.5

Loading Charge A/F 1.3 Sep. Line angle Deg. 31

Soutirage % 11.6

Ord.Sep.diam % 56

Date

Cement Type

Production t/h

Spec.surf. M2/kg

Cement Plant

Mill

Separator

Test no.

Wedag ZUB 36

Separation Analysis (Tromp Curve)

42.5

CEM II/A-M 32.5 R

Smidth 2.9 x 10.4

T curve soutirage regression ord.sep.diam. Linear (regression)

T separation curve

27

blaine

laser


2 1.0 11.7 10.3 8.1 11.7 10.3 8.1 8.2 2.42 10.62 0.23 22.81

4 3.0 19.5 17.7 13.9 7.8 7.4 5.8 5.5 1.73 7.20 0.24 24.09

8 6.0 29.4 26.9 20.9 9.9 9.2 7.0 6.9 2.09 9.03 0.23 23.18

12 10.0 36.2 32.8 24.9 6.8 5.9 4.0 4.8 1.20 5.96 0.20 20.06

21 16.5 54.2 47.8 33.0 18.0 15.0 8.1 12.6 2.42 15.04 0.16 16.11

30 25.5 64.1 56.1 37.5 9.9 8.3 4.5 6.9 1.35 8.28 0.16 16.25

60 45.0 84.0 74.8 53.0 19.9 18.7 15.5 13.9 4.64 18.58 0.25 24.95

90 75.0 94.3 87.5 71.2 10.3 12.7 18.2 7.2 5.44 12.66 0.43 42.99

128 109.0 98.4 96.0 89.9 4.1 8.5 18.7 2.9 5.59 8.47 0.66 66.06

192 160.0 99.8 98.9 96.1 1.4 2.9 6.2 1.0 1.85 2.84 0.65 65.40

total 591.6 548.8 448.5 Materials in cycle residue [determ. ALPINE]

t/h 30 µm 40 µm 60 µm 90 µm 200 µm

calc. F/A 0.7009 final 126.0

G/F 0.2991 feeding 179.8

coarse 53.8


Soutirage % 19.0

Sep.diam µm 131

CPC 30

Polysius 4.6 x 14.5

Polysius TSU 6.5 (n.ro 2)

328

325

126.0

Date


Cement Plant

Mill

Separator

Test no.

Cement Type

Production t/h

Spec.surf. M2/kg


T separation curve


blaine

laser


2 1.0 9.8 6.6 3.6 9.8 6.6 3.6 6.6 1.18 7.76 0.15 15.25

4 3.0 16.8 11.9 6.3 7.0 5.3 2.7 4.7 0.89 5.59 0.16 15.89

8 6.0 29.4 22.9 9.2 12.6 11.0 2.9 8.5 0.95 9.41 0.10 10.13

12 10.0 39.6 31.3 10.3 10.2 8.4 1.1 6.8 0.36 7.21 0.05 5.02

21 16.5 62.1 46.9 11.4 22.5 15.6 1.1 15.1 0.36 15.46 0.02 2.34

30 25.5 73.7 55.1 13.0 11.6 8.2 1.6 7.8 0.53 8.31 0.06 6.33

60 45.0 93.8 74.8 35.1 20.1 19.7 22.1 13.5 7.27 20.76 0.35 35.01

90 75.0 99.4 85.9 59.8 5.6 11.1 24.7 3.8 8.12 11.88 0.68 68.36

128 109.0 99.9 93.8 83.5 0.5 7.9 23.7 0.3 7.79 8.13 0.96 95.87

192 160.0 100.0 96.4 91.5 0.1 2.6 8.0 0.1 2.63 2.70 0.98 97.51


t/h 30 µm 40 µm 60 µm 90 µm 200 µm

calc. F/A 0.6712 final 115.0 26.3 11.4 6.2 0.6 0.0

G/F 0.3288 feeding 171.3 44.9 32.6 25.2 14.1 3.6

coarse 56.3 87.0 76.9 64.9 40.2 8.5


Soutirage % 9.2

Sep.diam µm 77

Date

Cement Type

Production t/h

Spec.surf. M2/kg

Cement Plant

Mill

Separator

Test no.

332

397

Wedag ZUB 60


115.0

42.5 PTL

Tosi 4.6 x 15.0


T separation curve

29


blaine

laser


2 1.0 16.9 12.0 11.8 16.9 12.0 11.8 4.3 8.82 13.09 0.67 67.42

4 3.0 30.2 22.9 21.4 13.3 10.9 9.6 3.4 7.18 10.53 0.68 68.15

8 6.0 42.5 32.9 30.4 12.3 10.0 9.0 3.1 6.73 9.83 0.68 68.44

12 10.0 54.1 41.2 37.0 11.6 8.3 6.6 2.9 4.94 7.86 0.63 62.78

21 16.5 69.8 52.3 45.9 15.7 11.1 8.9 4.0 6.65 10.62 0.63 62.69

30 25.5 79.5 60.6 53.3 9.7 8.3 7.4 2.4 5.53 7.98 0.69 69.34

60 45.0 97.2 82.9 77.5 17.7 22.3 24.2 4.5 18.10 22.56 0.80 80.21

90 75.0 100.0 94.4 91.2 2.8 11.5 13.7 0.7 10.24 10.95 0.94 93.55


t/h 30 µm 40 µm 60 µm 90 µm 200 µm

calc. F/A 0.2523 final 85.0

G/F 0.7477 feeding 337.0

coarse 252.0


Soutirage % 65.9

Sep.diam µm 65

CEM II/A-S 42.5 R

Smidth 4.0 x 12 (2100 kW)

Smidth CV 6m (short)

85.0

Date


Cement Plant

Mill

Separator

Test no.

Cement Type

Production t/h

Spec.surf. M2/kg

T separation curve


4. CONCLUSIONSOn the separator performance problem, it is important to remember the assumption of B. Beke (Principles of comminution, Akademiai Kiado, Budapest, 1964):“…luckily the separators do not have a 100% performance, otherwise it would not be possible

to create the granulometries necessary for the development of the cement characteristics…”.

In our opinion it may be added that all the formulas, results and evaluations obtained with theavailable methods, are NOT transferable; that means that an objective analysis of the functioningof the separator is not possible if separated from the analysis of the combined mill.Indisputable is the fact that, inside a grinding system, each single variation of the separationparameters can affect the mill output (and vice versa), and this is revealed by the specific energyconsumption. The successive separation analysis will only confirm the variation (positive or nega-tive) of the parameters of evaluation.

With the above assumptions, and taking into consideration the usefulness of the analysis of aseparation process, we would like to emphasise our belief that it is impossible to have objectivecomparisons of other and different separators when installed on different circuits.

CAPACITY

M t/h “fresh” material feed = FA t/h separator feedF t/h fine materialG t/h coarse material

GRANULOMETRIES with a one reference particle dimension

a % passing of Af % passing of Fg % passing of G

FUNDAMENTAL EQUATION

A = F+ GA*a = F*F + G*G

LOADING CHARGE u = A/F Ratio between the separator feed A and final product F.

u = (f-g) / (a-g)

FINENESS PERFORMANCE Vf = F/A*100 Ratio between the final product F and the feed material A.

Vf = 1/uVf = (a-g)/(f-g) * 100

PERFORMANCE Ew = F/A * f/aEw = (a-g)/(f-g) * f/a

SEPARATION EFFICIENCY Ek = (a-g)/(f-g) * 100 * (f-a)/a * (100-a)

The performance is referred to a granulomoeric dimension:it indicates the feeding material that passes in the final pro-duct after the separation.

Always referred to a granulometric dimension, indicates theyield of the passing material in the product, reduced by theyield of the residue in the same.

SEPARATION ANALYSISSYMBOLOGY BASED ON VDZ MT 28 STANDARD

31


1. SYMBOLOGY

M = fresh feed (t/h)A = separator feed (t/h)F = separator final product (t/h)G = separator coarse material (t/h)a = passing of A (%)f = passing of F (%)g = passing of G (%)

We can define the “passing” of the material as the fraction (% in weight) of particles which have equal or lower dimensions to the granulometry of reference.

Fundamental equations

A = F + G [i]A*a = F*f + G*g [ii]

a = part in weight of a specific granulometric class of A (%)f = part in weight of a specific granulometric class of F (%)g = part in weight of a specific granulometric class of G (%)

We can define granulometric class the interval between the two granulometric measures.

A*a = F*f + G*g [iii]

33

2. GRANULOMETRIC CHARACTERISTICS THE SEPARATOR FLOWS

3. CIRCULATING LOAD CALCULATION

It’s expression is Tc = A/F

It is defined by the granulometric analysis of the 3 separator flows (see table – point 2) using the Koulen

formula.

Being fi ai gi the fine product, feeding material and coarse passing on the mesh i (for the following dimen-

sions: 2,4,8,16,32,64 e 128 µm).

Example

Granulometric Final product Coarse Feedingintervals f % df g % dg a % da

0-2 13.3 13.3 7.4 7.4 10.3 10.32-4 22.2 8.9 12.0 4.6 17.1 6.84-8 34.6 12.4 17.2 5.2 25.3 8.28-16 51.8 17.2 23.5 6.3 37.5 12.216-32 73.2 21.4 32.8 9.3 52.5 15.032-64 92.0 18.8 54.3 21.5 72.1 19.664-128 99.4 7.4 75.1 20.8 87.6 15.5> 128

Σ i 386.5 222.3 302.4


4. SEPARATION CURVE DRAWING - “T CURVE”[with recomposed separator feed]

We calculate:- performance in fine material Vf = 1/Tc- performance on “big” material Vg = 1-Vf- the feeding fraction between 2 granulometric measures.

a = df*Vf + dg*Vga = df*Vf + dg(1-f)

- the separation degree T

Example

We calculate the T separation degrees, with the data from the table - point 2.

Tc = 2,04 Vf = 1/Tc = 0.4902 Vg = 1-Vf = 0,5098

Granulometric Final Coarse f g Feed Separation Meaninterval product degree diameter

m df[%] dg[%] Df*Vf Dg(1-Vf) f+ g T[%] m0-2 13.3 7.4 6.52 3.77 10.29 36.7 12-4 8.9 4.6 4.36 2.34 6.70 34.9 34-8 12.4 5.2 6.08 2.65 8.73 30.3 68-16 17.2 6.3 8.43 3.21 11.64 27.6 1216-32 21.4 9.3 10.49 4.74 15.23 31.1 2432-64 18.8 21.5 9.21 10.96 20.17 54.3 4864-128 7.4 20.8 3.63 10.60 14.23 74.5 96> 128

35

5. T CURVE DRAWING

The curve is resolved in two lines:

- Horizontal: the ordinate is the mean of the separation degrees value, represented by the corre-spondent points. The points to be considered for the calculation of the mean value (Soutirage)are below the ordinate at the abscissa point 1 µm;- a regression line related to the succeeding points on the ascending part of the curve;- [in practice it is better to cancel one or more points on the right that curve the line to the bot-tom. Only the 2 points situated more or less straddling the normalized separation diameter will beoften considered. For this reason it is useful to consider the point on the right of the horizontalline.

6. SEPARATION CHARACTERISTIC PARAMETERES (NORMALIZED)

6.1 SoutiragesMaterial passed through the separator without being classified. It is measured by the minimumordinate (horizontal) of the T curve, calculated as per point 5.

s

d

100


6.2 Separation diameter ΦpThis diameter corresponds to a probability of 50% to be distributed within coarse and fine mate-rial. This per centage is not applicable to all the feeding material, but only to the one that has real-ly been separated; that means 100% - soutirage s. The ordinate is calculated as follows: s +(0,5*(100-s)) and we calculate, on the pending part of the T curve, the corresponding abscissa.

6.3 Imperfection IRepresents the T curve inclination (perfect separation = 0). It is represented by the difference bet-ween the diameters correspondent to the separation coefficients 25% e 75% for the material thathas really been separated. That means 100%- soutirage s. On the separation chart the followingordinates have been reported:

S+(0,25*(100-s))S+(0,75*(100-s))

On the pending part of the curve are defined the correspondent diameters Φ25 e Φ75; The calculation is the following:

100

Φp

Φ25

Φ25 -Φ75I =2 Φp

Φ75

S+(0

.5*(1

00-s

))

d

d

100

S+(0

.25*(1

00-s

))

S+(0

.25*(1

00-s

))

Products

MApei Grinding Aid/CPack set inhibitors for cement

DESCRIPTIONMA.G.A./C are high performance grinding aidsgenerally used to increase mill production and to improve the cement quality.

They are highly concentrated additives formulatedwith only selected raw materials, to guaranteeabsolute constancy of quality and superiorperformance.

TECHNICAL CHARACTERISTICSMA.G.A./C, thanks to their polar nature, notablyreduce the attraction forces of cement particleswhich are the main cause of agglomeration insidetubular mills (pack-set). They are also able to modifythe hydrates’ structure (see pictures on the backpage).

The disappearance or the remarkable reduction ofpack-set phenomena favourably modify thegranulometric curve of the finished product with aconsequent beneficial effect on the strengths andefficiency of theseparation.

It is therefore possible to obtain important productionincreases (savings in kWh/t) or, with the sameproduction, improvements of the specific surface ofthe finished cement.

Specific formulations allow the modification of thehydration products of the cement increasing the earlyand/or ultimate strengths.

APPLICATION PROCEDUREMA.G.A./C may therefore be successfully utilized inall cases of pack-set phenomena (not due tohumidity) inside the mill, particularly in the grinding of Portland and limestone cements. Productiveincreases generally may vary between 10% and30%, depending on the fineness of the cement, on the grinding system available, on clinkermineralogical composition, on the additive dosageetc.

When the right conditions are present, specificformulations for limestone cements allow theincrease of even the ultimate strengths; it is possibleto decrease the percentage of clinker in the cementrecipe, with no loss in cement quality.

CHEMICAL-PHYSICAL DATAPlease refer to the appropriate safety data sheets.

DOSAGE• 0.1-0.5 kg/t.

• Ordinary Portland cements (2600-3200 cm2/g): 100-200 g/t.

• Rapid Hardening Portland cements (3200-4600 cm2/g): 200-500 g/t.

• Limestone cements: 250-500 g/t.

We recommend the higher dosage threshold inpresence of high percentages of limestone and when

MA.G.A./C

MA.G.A./C

tttt

tt

41

1. TRIAL DESCRIPTION

a. Plant description

b. Trial objectives and additive selection

2. TRIAL RESULTS

a. Immediate results during the Trial

b. Post-trial results

c. Technical analysis

3. CONCLUSIONS

Report of an industrial trial performedwith MA.G.A./C1 during the production of high fineness CEM I type cements

INDUSTRIAL TRIAL WITH MA.G.A./C1

42

a) Plant Description

The cement grinding facility consists of two mills side by side, one dedicated to the grinding ofcements while the second is dedicated to the grinding of slag. Our trials were performed on thecement mill which has the following characteristics:

Cement Mill UMS Mill 5.0 x 14.0, two chambers; installed power 5750 kW.

The cement grinding circuit is closed with a 3° generation Sepax 450M222 Separator. Separatorand mill ventilation is realised with sleeve filters. (Fig. 1 – Flow sheet diagram).

b) Trial objectives and additive selection

An industrial trial to evaluate the performance of the product MA.G.A./C1, a high performance grin-ding additive formulated as a concentrated grinding aid able to increase early strengths, on theproduction of CEM I (400 m2/kg Blaine) and CEM I (550 m2/kg Blaine) cements. The plant’s objec-tives was to increase the hourly production (t/h) of the mill as the cement plant had significantlyincreased their quota of the local market and needed to maximise their production output.


Fig. 1 Flow sheet diagram

1. Fresh material feed2. Cement mill3. Elevator4. Separator5. Mill bag filter6. Bag filter

43

a) Immediate results during the trial

Table N°1 in paragraph 3.1 shows the average hourly production obtained during the trial. Theseresults confirm the validity of the MA.G.A./C1 product as a powerful grinding aid.

CEM I (400 m2/kg)In the case of the CEM I (400) trial the average production obtained with Mapei MA.G.A./C1 was144.3 t/hr. This corresponds to an increase of +8.5% with respect to the blank, i.e. without an addi-tive, which was 133.0 t/hr. This blank value is an average value for the month previous to the trial.Grinding without the additive was not possible on this cement due to silo space restrictions. Thevalue of Blaine measured on the mixed sample is 411 m2/kg. This is higher than the desired value(+11 m2/kg) and may indeed be translated into a further increase in hourly production.

2. TRIAL RESULTS

Table N°1.Details Units Blank MA.G.A./ % Blank MA.G.A./ %

C1 Difference C1 DifferenceCement Type CEM I CEM I CEM I CEM I

(400 m2/kg) (400 m2/kg) (550 m2/kg) (550 m2/kg)

Additive g/t --- 300 --- 300DosageProduction t/h 133.0* 144.3 +8.5 74.0 83.5 + 12.8Specific S.A. m2/kg 411 562 539 - 4.1Specific S.A. km2/h 59.3 41.6 45.0 + 8.2productionSpecific Mill kWh/t 36.2 70.7 63.0 - 10.9ConsumptionSpecific consumption kWh/km2 125.8 116.9 - 7.1S.A. productionR1 MPa 20.7 27.2 30.5 +12.1R2 MPa 35.2 41.3 44.3 +7.3R28 MPa 59.9 62.4 62.8 +0.6* Average Plant Data

44CEM I (550 m2/kg)In the case of the CEM I (550) trial the average production obtained with Mapei MA.G.A./C1 was83.5 t/hr. This corresponds to an increase of +12.8% with respect to the blank, i.e. without anadditive, which was 74.0 t/hr. This is a significant increase for such high Blaine grinding and is apositive result which allows a reduction of the specific mill consumption from 70.7 to 63.0 kWh/t.Another result is a higher surface production: +8.2% (45.0 km2/h versus 41.6 km2/h).

Additives 133.0 144.3

Mill Production CEM I (400)

133.0

144.3

130.0

135.0

140.0

145.0

150.0

Additives

Blank MAGA/C 1

Additives 3..31440..0133 3

0..0150

0..0145

0..0140

0..0135


3..3144

0..0133

Blank MAGA/C 1

0..0130

Additives


74.0

83.5

70.0

75.0

80.0

85.0

Additives

Blank MAGA/C 10..085

0..080

0..075


5..583

0..074

Blank MAGA/C 1

0..070

Additives

CEM I (550) - Strengths

27.2

30.5

21.0

23.0

25.0

27.0

29.0

31.0

33.0

1 Day


0..031

0..029

0..027

0..025

023


5..530

2..227

Blank MAGA/C 1

0..023

0..021

1 Day


41.3

44.3

40.0

41.0

42.0

43.0

44.0

45.0

2 Days


0..044

0..043

0..042

041


3..344

3..341

Blank MAGA/C 1

0..041

0..040

2 Days

b) Post-Trial results

The results regarding cement strengths are available in Table N°1. All testing is carried out inaccordance with the European Standard EN 196. The cement without additive where available iscompared to that produced with Mapei MA.G.A/C1.

CEM I (550 m2/kg)As regards the strengths at 1 day there is an increase of +12.1% with MA.G.A/C1 from 27.2 to30.5 MPa, while at 2 days the increase is +7.3% from 41.3 to 44.3 MPa. The results at 28 daysare practically the same.

45

c) Technical analysis

The following samples were taken from the separation circuit consisting of a FLS SEPAX 450 typeseparator during the industrial trial:

• finished product• separatore feed • return or recycle – material returning to the mill

On these samples granulometric particle size analysis was carried out with the Alpine sieveequipment and the complete particle size distribution curve was defined using a Coulter LS laserequipment. Successively the following were determined: Separation performance according to DIN andTromp.

Separation Performance According to DIN:

The calculated values according to the DIN are given in Table N°2 determined from the “Dry’’ resi-dues of the materials tested; when one considers the very high specific surface area of the ‘‘fini-shed’’ product: > 400 m2/kg, the calculated characteristic parameters: F/A and ETA w, lie withinthe “normal’’ range. The ETAw parameter is interesting, as it expresses the “ability” of the separator to “clean” thematerial being fed; in our case, on the 40 µm control mesh, the “recovered” fraction of less than-40 µm amounts to 67 % of the total present in the feed material. This can be defined as a “goodresult”.

These results are positive when one considers the increase in production obtained at the sametime. The values of Blaine reported indicates that the cement produced without the additive is sli-ghtly finer than that produced with MA.G.A/C1. Hence here one can appreciate the positiveinfluence of the product’s formulation on the early strengths.

46

Material: CEMENT

Mill: FLS UMS Cement Mill 5.0 x 14.0

Separator Brand: FLS

Type: SEPAX 450

Separation Performance According to DIN, Calcolated with Alpine

TABLE 2 [passing values] Output calculation

µm final p. sep. feed return from TABLE 2 a (D) µm 40

(D) (f) (a) (g)

20 F= t/h 144.3 144.3

30 87.5 44.0 19.0 A= t/h 389.1 389.1

40 93.5 52.5 28.0 G= t/h 244.8 244.8

50

60 99.5 75.0 59.5 A= t/h

70 F= t/h 0.0 0.0

90 100.0 86.0 78.5 G= t/h 0.0 0.0

200

Total 380.5 257.5 185.0

(f) (a) (g) control mesh [D]

PERF a(D) 93.5 52.5 28.0 40.0 µm eta w 0.67

format 0.00

mean a (D) µm

values µm 40

CIRCULATING LOAD A/F 2.70 2.67

EFFICIENCY F/A 0.37 0.37

PERF.ACC. DIN ETA w 0.55 0.67 (§)

CLASS.EFFICIENCY ETA k 0.61

DIVISION PERFORM. ETA s 0.65

NOTES (Rosin-Rammler) (§) intended as "ability" of the

1 A/F f-g/a-g separator to recover the finished

2 F/A (1/U) product (F) the material (D)

3 ETA w 1/U*f/a present in the feed A.

4 ETA k (a-g)/(f-g)*100*(f-a)/a*(100-a)

5 ETA s a-g/a*100/100-g

Separation Performance Analysis according to DIN

Yield

Performance

EFFIC.CLASS.

PERF.DIVIS.

(fraction separated/theorical)-(NON separated fraction)

(granulometric variation)

(effective yield/possible)

U

47According to Tromp:

From the laser particle size curves of the material in the separator circuit, the corresponding Tcurve (of Tromp) was calculated which represents for the various granulometric fractions thedevelopment of the separation process; Table 3 shows the T curve drawn, on the co-ordinates ofa semi-logarithmic graph and the calculation of the characteristic parameters elaborated accor-ding to CETIC.

SepaxCirculating load dimensionless 3.1Soutirage % 23.8Diameter of separation µm 42Inclination angle of regression line (2^ branch separation curve) °G 47

The profiles of the curves and the parameters deducted from them allow the operation of theseparator to be judged as ‘‘discreet’’. In relation to the not very high circulating load: approx. 3,the error of “soutirage” (by pass) is NOT very good; this may depend perhaps on an inadequateventilation.Also as regards the profile of the 2^ branch of the T curve, which represents the type of separa-tion, an “inclination” > 40°G can be considered as “acceptable”.

48

blaine

laser

dim.µm f a g df da dg df*F/A dg*G/F a (§) T (%)

2 1.0 9.7 4.5 2.2 9.7 4.5 2.2 3.1 1.47 4.56 0.32 32.2

4 2.0 17.1 8.1 3.6 7.4 3.5 1.4 2.4 0.96 3.34 0.29 28.8

6 4.0 23.5 11.0 4.6 6.4 2.9 1.0 2.0 0.69 2.73 0.25 25.1

8 6.0 29.5 13.5 5.3 6.0 2.5 0.7 1.9 0.49 2.41 0.20 20.5

10 8.0 34.9 15.8 5.9 5.4 2.3 0.5 1.7 0.37 2.10 0.18 17.6

15 11.5 46.8 20.7 7.1 11.9 4.9 1.3 3.8 0.86 4.67 0.18 18.5

20 15.0 56.4 24.8 8.6 9.6 4.1 1.4 3.1 0.98 4.05 0.24 24.2

30 22.5 71.0 31.6 11.9 14.6 6.9 3.4 4.7 2.28 6.95 0.33 32.8

40 30.0 83.7 39.1 17.4 12.7 7.4 5.5 4.1 3.76 7.82 0.48 48.0

60 45.0 94.7 54.9 36.6 11.0 15.9 19.2 3.5 13.05 16.76 0.79 78.8

90 65.0 97.4 70.3 60.5 2.7 15.4 23.8 0.9 16.21 17.08 0.95 94.9

100 80.0 98.6 74.5 66.5 1.2 4.2 6.0 0.4 4.09 4.47 0.91 91.4

total 663.3 368.8 230.2 Materials in cycle

t/h laser blaine 30 µm 40 µm 60 µm 90 µm 200 µm

calc. F/A 0.32 final 144.3 362 410 12.5 6.5 0.5 0.0 0.0

G/F 0.68 feeding 451.0 181 206 56.0 47.5 25.0 14.0 3.0

coarse 307.0 94 122 81.0 72.0 40.5 21.5 4.0


Soutirage % 23.8 Efficiency Evaluation =(Sep. Line angle)

Sep.diam µm 42 Imperfection ad 0.43

Grinding with MA.G.A./C 1

Production t/h

Spec.surf. M2/kg

Average

Cement Plant

Mill

Separator

Test no.

spec. Surface area m2/kg residue [determ. ALPINE]

FLS UMS Cement Mill 5.0 x 14.0

FLS SEPAX 450


CEM I 400

362

410

144.3

Description

Cement Type

T separation curve (acc. CETIC) - CEM I 400 with MA.G.A./C 1

49

The results obtained can be considered to be very positive both in terms of production (t/hr) andcement quality (MPa at 1 & 2 days). The most important objective of the plant at the time was to increase hourly production and theresults obtained are very interesting when one considers the low dosage (300 g/t) of theMA.G.A./C1 product.

MA.G.A./C1 guarantees significant production increases and increases early strengths. Hourlycement production capacity has reached the levels desired by plant management, at the sametime reducing production energy costs.

3. CONCLUSIONS

Cement Blank MA.G.A./C1 %IncreaseCEM I (400 m2/Kg) 133.0 144.3 +8.5CEM I (550 m2/Kg) 74.0 83.5 +12.8

51

tttt

tt




2. TRIAL RESULTS



3. CONCLUSIONS

Report of an industrial trial performedwith MA.G.A./C2 during the production of CEM I 42.5 R

INDUSTRIAL TRIAL WITH MA.G.A./C2

52


The cement grinding facility has a group of four mills side by side and the trial was performed onmill number 3 which has the following characteristics:

FLS Mill of dimensions 4.6 m x 16.0 m, two chambers of which the first chamber is 3.0 m and thesecond is 13 m long; installed power is 4500 kW. The grinding circuit is closed with a high efficiency SEPOL SVZ separator, with an ESP filter onthe mill. (Fig.1 - Flow sheet diagram)

B) Trial objectives and additive selection

An industrial trial to evaluate the performance of the additive MA.G.A./C2, a high performancegrinding additive formulated to increase 28 day strengths, on the production of the cement CEMI 42.5 R (95.6% Clinker and 4.4% Gypsum). The plant’s objective was to increase the 28 daystrengths in order to maintain it’s market leader position without having to alter the quality of theirclinker.


Fig. 1 Flow sheet diagram

1. Fresh material feed2. Cement mill3. Elevator4. Separator - SEPOL SVZ5. ESP Filter

53MA.G.A./C2 was proposed given it’s ability to meet the client’s objectives of increased 28 daysmechanical strengths while at the same improving the cement mill’s hourly production. The per-formance of the product in terms of it’s excellent grinding aid characteristics and strength impro-vement are directly related to the product formulation and the high quality of the raw materialsutilised.


The MA.G.A./C2 product was added onto the clinker transported on the conveyor belt just befo-re the entrance to the mill at a dosage of 450 g/t. The diagram in Figure 2, related to the circula-ting load (elevator cycle absorption), clearly shows the effect of the additive on the grinding cycle.The yellow line represents the elevator consumption while the red line represents the fresh mate-rial feed. Subsequently the circulating load has been returned to previous levels by the followingoperations:

• Mill output increase • Cement fineness improvement

2. TRIAL RESULTS

54 Table N°1.Details Units Blank MA.G.A./C2 % DifferenceCement Type CEM I 42.5 R CEM I 42.5 R ---Additive Type Blank MA.G.A./C2 ---Additive Dosage g/t -- 450 ---Production t/h 82.1 90.2 + 9.9 %Specific surface m2/kg 408 410 + 0.5 %areaSpecific surface km2/h 33.5 37.9 + 13.0 %area productionSpecific kWh/t 51.7 47.3 - 8.5 %mill consumptionSpecific kWh*t-1/ km2 126.6 112.6 - 11.1 %consumptionsurface area productionFlow mm 73 83 + 13.7 %Initial Setting min. 95 80 - 16.7 %TimeStrengths 1 days MPa 15.6 20.1 + 29.4 %

2 days MPa 25.2 28.4 + 13.0 %28 days MPa 49.8 55.6 + 11.7 %

55Table N°1 in paragraph 1.4 shows the average hourly production obtained during the trial. Theseresults confirm the validity of the MA.G.A./C2 product. The mill output increase t/h: + 9,9%, hasbeen realised with a slightly higher Blaine specific surface: 410 m2/kg versus 408 m2/kg; a fur-ther result is a higher surface production: + 13% (37.9 km2/h versus 33.5 km2/h).

The results show a reduction of the average specific mill consumption from 51,7 to 47,3 kWh/t.

b) Post-Trial analysis

The results are available in Table N°1. All testing was carried out in accordance with the EuropeanStandard EN 196.

Table N°1 shows information regarding cement strengths, Blaine, setting times and cement flow.The cement produced without any additive, i.e. Blank, is compared to that produced withMA.G.A/C2.

As regards the strengths there are increases at all ages with MA.G.A/C2. At 1 and 2 days theincreases are respectively +29,4% and 13,0%. There is also a reduction in the setting time from95 minutes to 80 minutes, particularly appreciated by the cement plant as this cement is for themost part employed by precast clients.Meanwhile at 28 days the strengths have increased from 49,8 MPa to 55,6 MPa correspondingto an increase of +11,7%.

This increase at 28 days fully meets the clients objectives while at the same time obtaining asignificant production increase.

Compressive Strengths

10.0

20.0

30.0

40.0

50.0

60.0

1 day 2 days 28 days

Days


0..050

0..040


Blank


MAGA/C 2

0..030

0..020

0..010

2 days1 day 28 days2 days

Days

28 days

15.6

20.125.2

28.4

49.8

55.660.0

50.0

40.0

30.0

20.0

10.0

56

The comparison between the energy consumption indexes, with reference to the strength cha-racteristics of the cement produced (kWh*t-1/MPa), clearly demonstrates the improvements whichmay be obtained using a high performance product such as MA.G.A/C2.

Laser particle size analysis of the cements are available in Fig. 3 (Blank cement) and Fig. 4(MA.G.A./C2). The laser distribution curves demonstrate the superior fineness (higher laser spe-cific surface) of the cement with the additive even though at the same time significant increasesin production are achieved. The increases in strengths at all ages can be principally accredited tothe positive effect of the MA.G.A./C2 additive.

In Fig. 5 and Fig. 6 the granulometric curves for the two cements produced have been drawn onthe RRB grid using data from the laser analysis, based on the correspondent regression equa-tion, calculating also the characteristic distribution parameters.

The two distribution lines are quite similar, having the same uniformity coefficient(n) of 0,66 whichalso is not particularly high. This could possibly be interpreted as being related to a low or per-haps insufficient level of air for separation.

The principal objective of the client to increase 28 day strengths on the CEM I 42.5 R has beenfully achieved through the use of the MA.G.A./C2 product , increasing strengths from 49.8 MPato 55.5 MPa equivalent to an increase of +11.7%. At the same time a production increase of+9.9% has been obtained further improving the client’s grinding performance while reducingenergy costs.

The MA.G.A./C2 product is an effective solution where ultimate strength increases are specificallyrequired on Portland and on blended cements where there is a significant limestone addition.

3. CONCLUSIONS

Description Blank MA.G.A./C2 %VariationStrengths at 28 days 49.8 55.6 +11.7%

(MPa)Production 82.1 90.2 +9.9%

(t/h)Energy Consumption 51.7 47.3 -8.5%

(kWh/t)

Description Blank MA.G.A./C2kWh*t-1/MPa kWh*t-1/MPa

28 days 0.96 0.85

57Fig. 3 Blank cement

58 Fig. 4 MA.G.A./C2

59Fig. 5

blaine

laser

dim.µm pass. (%)

1 3.4 30 µm 40 µm 60 µm 90 µm 200 µm

2 7.7 Residue (%) 34.5 24.6 11.1 5.7 0.0

4 14.8

6 21.4 Linear Regression Y = a + n x

8 27.4

10 32.8 Uniformity Coe (n) 0.6606 Line coordinates

15 44.1 Cross (a) -2.2878 X(µm) Y(% R)

20 52.8 Line Angle (Gr) 33.5 2 85.2 14.8

30 65.5 Charact. Diam. (Xo) Res. 36,8% 32 µm 90 13.8 86.2

40 75.4 Corrsp. Diam. P80 66 µm 32 36.8 63.2

60 88.9

90 94.3

Notes

Equation of the Regression Curve (RRB Curve) according to Laser analysis

CEM I 42.5 R

305

408

Description

Cement TypeCement Plant

Mill

Separator

Test no.

Sepol SVZ

Blank, June 2004

Production t/h

Spec.surf. M2/kg

Cement Mill

GRANULOMETRIC CURVE ACCORDING TO RRB

60 Fig. 6

blaine

laser

dim.µm pass. (%)

1 4.1 30 µm 40 µm 60 µm 90 µm 200 µm

2 9.1 Residue (%) 30.2 20.0 8.3 4.1 0.0

4 17.3


8 30.6


15 47.3 Cross (a) -2.1600 X(µm) Y(% R)

20 56.2 Line Angle (Gr) 33.4 2 83.3 16.7


40 80.0 Corrsp. Diam. P80 54 µm 26 36.8 63.2

60 91.7

90 95.9

Notes

Sepol SVZ

MA.G.A./C 2, June 2004

Production t/h

Spec.surf. M2/kg

Cement Mill

Cement Plant

Mill

Separator

Test no.


CEM I 42.5 R

344

410

Description

Cement Type


MApei Grinding Aid/MPack set inhibitors for minerals

DESCRIPTIONMA.G.A./M are high performance grinding aids forminerals (limestone, quartz, feldspar, zirconium,sands) and raw materials and are suitable forobtaining a higher level of fineness.

They increase mill output, and modify the particlesize distribution, improving the dry flowcharacteristics of the grinded materials.

They are used in dry grinding processes, preferablyin tubular mills, but are also effective in vertical mills,hammers mills, etc.

TECHNICAL CHARACTERISTICSMA.G.A./M, thanks to their polar nature, notablyreduce the attraction forces of cement particleswhich are the main cause of agglomeration inside the mill. MA.G.A./M act by coating the particleswhich normally cause agglomeration, with a mono-molecular film which neutralizes the surfaceelectrical charges, improving dry flow characteristicsduring transport, storage and handling.

APPLICATION PROCEDUREMA.G.A./M has been conceived taking into accountthe characteristics of the different minerals and theirfinal use. A first distinction can be made betweenadditives for the grinding of limestone and additivesfor the grinding of other minerals.

LimestoneGrinding limestone is always difficult due to thepack-set phenomena inside the mill. For this reasona highly effective grinding aid is recommended.

MA.G.A./M offers specific additives for:• limestone for the food industry;

• limestone for applications with controlled dielectricconstant (power line fillers, etc.).

Other mineralsOther minerals such as quartz, feldspar, sands etc.are usually used in the ceramic industry (tiles,sanitary ware), glass and refractory productsindustry. For these minerals with a low agglomerationtendency, specific formulations of MA.G.A./M areavailable.

CHEMICAL-PHYSICAL DATA Please refer to the appropriate safety data sheets.

DOSAGE0.3-0.8 kg/t.The optimum dosage depends on the grindingsystem and material type and fineness. In any case ithas to be found through a reliable industrial trial,preferably with the help of MAPEI Cement AdditivesDivision technicians, that are also available to selectthe most suitable additive for each specific need.

MA.G.A./M

MA.G.A./M

MApei PerformanceEnhancer/SPack set inhibitors andstrength enhancers

DESCRIPTIONMA.P.E./S are highly concentrated grinding aidsformulated with only selected raw materials, toguarantee absolute constancy of quality and superiorperformance.

They are additives formulated to improve cementquality (early and/or ultimate strengths) and to aidcement grinding by increasing mill production.

TECHNICAL CHARACTERISTICSMA.P.E./S also guarantee, in addition to all theadvantages which come from the usage of thegrinding aids (refer to MA.G.A./C), remarkableincreases to early and ultimate strengths.

At equal cement fineness, MA.P.E./S are able toincrease mechanical strengths thanks to a bettergranulometric redistribution of the finished cement,to a higher fineness and to a higher rate of thecalcium silicates hydration, which can be significantlymodified.

APPLICATION PROCEDUREMA.P.E./S may be successfully utilized in thegrinding of blended cements (i.e. pozzolanic, blastfurnace slag and fly ash cements) and in all caseswhere a significant increase in early strengths isneeded.

MA.P.E./S are generally formulated to reach the

goals placed by the cement factory. The obtainablestrength increases may be used to improve thebinder quality, reaching early strengths quite similarto those of Portland cements.Alternatively, keeping the cement quality unaltered, it is possible to substitute in the mixture up to 4-6%of clinker with blended material.

In normal conditions the strength increases are in the range of 20-50% after one day and 5-15% after28 days.MA.P.E./S can also be used successfully whengrinding Portland and limestone cements to increasesignificantly early strengths.


DOSAGE1.0-3.0 kg/t.We suggest the higher dosage threshold, if the aim is the substitution of clinker points with blendedmaterial (i.e. blast-furnace slag, fly ash, pozzolan).

The optimum dosage, in any case, has to be found through a reliable industrial trial, preferablywith the help of MAPEI Cement Additives Divisiontechnicians.

MA.P.E./S should be added to the clinker on the mill feed conveyor belt or sprayed in the first mill

MA.P.E./S

MA.P.E./S

65

tttt

tt




2. TRIAL RESULTS




3. CONCLUSIONS

Report of an industrial trial performedwith MA.P.E./S during the preparation of CEM I 52.5

INDUSTRIAL TRIAL WITH MA.P.E./S

66


In the cement plant of reference, the clinker is produced in a rotary kiln with cyclone preheatersproduced by PSP Eng., with a potentiality of 2500 t/d. The cements produced in the plant are:CEM I 52.5 R, CEM II/AL 42.5 R, CEM IV/B 32.5 ARS.

The industrial trial has been performed on a grinding system Wyss 3.2 x 14 (see Fig. 1) during theproduction of the CEM I 52.5 R.


MILL

Øut (m) lg ut (m) Vut (m3)

REDUCTION GEAR brand

3.00 4.20 30.40 type

3.00 9.10 65.30 Installed power kW

rpm (n1/n2) n/1'

6.0 13.3 95.7 rotation speed n/1'

1^cham 2^cham 3^cham Critical speed %

100 ø t Loading device type

90 ø t diameters [in/out] m

80 ø t 15 CYCLE ELEVATOR type

70 ø t 10 capacity t/h

60 ø t 10 STATIC SEPARATOR type

50 ø t 5 10 diametre m

40 ø t 20 SEPARATOR brand

30 ø t 50 type

25 ø t diametre m

20 ø t Q air Em�/h

25 ø x 25 Lg t FILTERS

22 ø x 22 Lg t type

20 ø x 20 Lg t model

16 ø x 16 Lg t chambers no.

1^cham 2^cham 3^cham filtering surface m�

Total t 40 80 FILTER FAN

Filling Level % 29.9 26.6 capacity Em�/h

Mill Total t pressure mbar

LININGS head 1^cham 2^cham 3^cham temperature °C

type wave classifying FEEDING MEASURES No.

blocking system type

material

DIAPHRAGM

type double discharge

slots mm 8 10 CEMENT TRANSPORT

material tipo type

ø central hole mm capacity t/h

regulable no

position

pneumatic/conveyor

Drying chamber FLS

1^chamber Symetro

2^chamber 1850

3^chamber 990/16.3

INSTALLED POWER

CHAMBER DIMENSIONS

Total values 16.3

BALL CHARGE 67.1

channel

150

Wedag

cycle elevator kW measuring

contr.gravim.sep.refusal

electronic ear

ZUB 32

3.2

50,000

mill

80

yes

yes

GRINDING PLANT CHARACTERISTICS

1850 Kw

120

Pulse Jet

sleeve/tissue

mill

37,600

36

REGULATION SYSTEM

Fig. 1

67

b) Trial Objectives and additive selection

A “strength enhancer” has been added to the CEM I 52.5 R type cement, at a dosage of about2.5-3.0 kg/t. When formulating our offer, we also proposed an enhancer, the MA.P.E./S, thatoffers, in addition, good grinding aid characteristics.We added our MA.P.E./S in the plant during a normal production cycle with the addition of the com-petitor’s product, without intervals, at the same dosage. The diagram in Figure 2, related to the cir-culating charge (cycle elevator absorption), clearly shows the effect of the additive on the grindingcycle. Subsequently the circulating charge has been re-settled by the following operations:

• Cement fineness improvement• Mill output increase

Fig. 2 Loading charge

Introduction of MA.P.E./S

clinker limestone gypsum pozzolan fly ashcycle

elevator

dynamicseparator

channel

pre-separator

filter

compressordosingsystem

cotto-2VISS

cementsampling

additive

Fig. 1 bis Flow sheet “Cement grinding” - cement mill no. 2 Wyss

68


The above results confirm the validity of our MA.P.E./S in comparison to the competitor additive.The mill output increase t/h: + 11%, has been realised with a higher Blaine specific surface: 504m2/kg versus 490 m2/kg; a further result is a higher surface production: + 13% (11.8 km2/h ver-sus 9.8 km2/h); in practice this means that, at the same specific surface of the competitor’s addi-tive: 490 m2/kg, a production of 24 t/h could have been realised, with a final increase of 20%.

b) Post-Trial Analysis

The physical-mechanical characteristics of the cement improved thanks to Mapei additive. Athigher strengths value at 1 and 2 days (+7 e + 6%) respectively, corresponds also better harde-ning times if compared to the competitor’s product: 250/1’ vs. 270/1’.It is also to be noted that the problem of the cement hardening is, in this case, particularly per-ceived, and the competitor's additive has been previously modified due to its tendency to exces-sively protract the hardening times.

c) Technical Analysis

During the trial with the MAPEI additive, some samples of the materials in the system have beencollected:• separator final product;• mill exit (separator feeding);• separator coarse.On the above samples we performed the granulometric analysis with the Alpine Siever, and thecomplete distribution curve has been determined by the laser Coulter LS.

Additive Type COMPETITOR MA.P.E./S DIFFERENCEDosage Kg/t 3.0 2.8 0.93Production t/h 20.0 22.2 1.11Specific surface m2/kg 490 504 1.03Spec. Surf. Produc. km2/h 9.8 11.1 1.13Mill consumption kW 1346 1350 1.00Specific mill cons. kWh/t 67.3 60.8 0.90Specif. surface kWh/km2 137.3 120.6 0.87production cons.

Flow mm 72 71 0.99Mixing water % 28.5 28.5 1.00Start hardening min 270 250 0.92

Strengths 1 d MPa 29.5 31.7 1.072 d 41.7 44.3 1.06

28 d 52.2 55.1 1.05

2. TRIAL RESULTS

69Wedag separatorThe separator working, in the plant closed circuit, has been evaluated with the usual analysismethods:• Performance based on the DIN rule;• Tromp separation curve.

Tables 7 e 8 report the performance calculation based on DIN, related to the granulometric deter-minations with the Alpine siever; Table 8, in particular, analyses the “cleaning” function of theseparator: quantity of fine material extracted from the feeding, referred to a 40 µm separation dia-meter.From the granulometric laser analysis of the loading charge, the T separation curve (foll. Tromp)has been traced on a scheme with linear coordinates: table 9. Then, the characteristic parame-ters of the curve following CETIC have been calculated: soutirage and curve inclination.

The strengths improvements obtained with the MA.P.E./S, if compared to the competitor’s pro-duct, did not change at different aging (1-28 days).Obviously also the comparison between the energy consumption indexes, referred to thestrengths characteristic of the cement produced (kWh/Mpa), demonstrates the better performan-ce of MAPEI additive:

The results of the Separator Performance Analysis have been summarised in TAB. 3.The granulometric curves of the 3 samples have been drawn on the RRB reticule(Fig. 4,5,6) based on the correspondent regression equation, calculating also the characteristicdistribution parameters:• uniformity coefficient n (curve inclination)• characteristic diameter Xo (diameter correspondent to R 36.8).For the final product the uniformity coefficient was 0.96 (line pending of 44 degrees); this is amean/high value, that is characteristic of the 2nd generation separators, when producing cementsthat need water additions on “normal” values.

3. CONCLUSIONS

COMPETITOR (kWh/MPa) MA.P.E./S (kWh/MPa)1 day 2.28 1.911, 3, 28 days 0.54 0.46

70 Tab. 4 Regression line equation

blaine

laser

dim.µm pass. (%)

2 15.1 30 µm 40 µm 60 µm 90 µm 200 µm

4 23.3 Residue (%) 17.7 8.8 2.3 0.3 0.0

6 29.7


10 40.9


20 65.4 Cross (a) -2.7215 X(µm) Y(% R)

30 82.3 Line Angle (Gr) 44.0 2 87.9 12.1


60 97.7 Corrsp. Diam. P80 27 µm 17 36.8 63.2

90 99.7

Notes

Wedag ZUB 32

Additive MA.P.E./S 5

Sample

Spec.surf. M2/kg

Wyss 3.2 x 14.0

Cement Plant

Mill

Separator

Test no.


CEM I 52.5 R

492

n.d.

Separator Final Product

Description

Cement Type


71Tab. 5 Regression line equation

blaine

laser

dim.µm pass. (%)

2 7.1 30 µm 40 µm 60 µm 90 µm 200 µm

4 10.9 Residue (%) 57.7 46.1 30.0 16.2

6 13.8


10 18.7


20 30.6 Cross (a) -3.4147 X(µm) Y(% R)

30 42.9 Line Angle (Gr) 40.5 2 94.2 5.8


60 70.0 Corrsp. Diam. P80 96 µm 55 36.8 63.2

90 83.8

Notes


CEM I 52.5 R

246

n.d.

Separator Coarse Product

Description


Mill

Separator

Test no.

Wedag ZUB 32


Sample

Spec.surf. M2/kg

Wyss 3.2 x 14.0


72 Tab. 6 Regression line equation

blaine

laser

dim.µm pass. (%)

2 10.3 30 µm 40 µm 60 µm 90 µm 200 µm

4 16.1 Residue (%) 40.9 30.9 19.5 9.7

6 20.5


10 28.4


20 45.4 Cross (a) -2.9117 X(µm) Y(% R)

30 59.1 Line Angle (Gr) 39.4 2 90.8 9.2


60 80.5 Corrsp. Diam. P80 62 µm 35 36.8 63.2

90 90.3

Notes

Wedag ZUB 32


Sample

Spec.surf. M2/kg

Wyss 3.2 x 14.0

Cement Plant

Mill

Separator

Test no.


CEM I 52.5 R

346

n.d.

Separator Feeding

Description

Cement Type


73

Material: CEMENT

Mill: Wyss 3.2 x 14.0

Separator Brand: Wedag

Type: ZUB 32

Separation Performance According to DIN

TABLE 2 [passing values] Output calculation

µm final p. sep. feed return from TABLE 2 a (D) µm

(D) (f) (a) (g)

20 F= t/h 22.2

30 A= t/h 70.4 0.0

40 98.8 86.1 80.4 G= t/h 48.2 0.0

50

60 99.7 88.2 82.8 A= t/h

70 F= t/h 0.0 0.0

90 99.9 95.3 93.1 G= t/h 0.0 0.0

200 100.0 99.7 99.6

Total 398.4 369.3 355.9

(f) (a) (g) control mesh [D]

PERF a(D) 98.8 86.1 80.4 40.0 µm eta w 0.36

format 0.00

mean a (D) µm

values µm 40

CIRCULATING LOAD A/F 3.17 3.23

EFFICIENCY F/A 0.32 0.31

PERF.ACC. DIN ETA w 0.34 0.36 (§)



NOTES (Rosin-Rammler) (§) intended as "ability" of the

1 A/F f-g/a-g separator to recover the finished

2 F/A (1/U) product (F) the material (D)

3 ETA w 1/U*f/a present in the feed A.

4 ETA k (a-g)/(f-g)*100*(f-a)/a*(100-a)

5 ETA s a-g/a*100/100-gPERF.DIVIS.

(fraction separated/theorical)-(NON separated fraction)



U


Yield

Performance

EFFIC.CLASS.

Tab. 5 Performance based on DIN

74

Material: CEMENT

Mill: Wyss 3.2 x 14.0

Separator Brand: Wedag

Type: ZUB 32

Separation Performance According to DIN

Calculation of the values related to [D] 40µm

Output calculation

(f) (a) (g) Dµm

98.8 86.1 80.4 40.0 F= t/h 22.2

A= t/h 71.7

passing residue G= t/h 49.5

t/h t/h

A 61.70 9.96 71.66 A= t/h

F 21.93 0.27 22.20 F= t/h 0.0

G 39.77 9.69 49.46 G= t/h 0.0

% t/h

separated 35.5 21.93 presence in final prod. (F) of [-D], [3]

in the feeding A.

not separated 64.5 39.77 material of [-D], present in A,

that remains in the separator coarse

Separation characteristic parameters Dµm 40

CIRCULATING LOAD A/F 3.23

EFFICIENCY F/A 0.31

PERF.ACC. DIN ETA w 0.36



NOTES (Rosin-Rammler)

1 A/F f-g/a-g

2 F/A (1/U)

3 ETA w 1/U*f/a

4 ETA k (a-g)/(f-g)*100*(f-a)/a*(100-a)

5 ETA s a-g/a*100/100-gPERF.DIVIS.

U

(fraction separated/theorical)-(NON

separated fraction)


Yield

Performance

EFFIC.CLASS.



Tab. 8 Performance based on DIN

75Tab. 9 Separation analysis

blaine

laser


2 1.0 15.1 10.3 7.1 15.1 10.3 7.1 6.3 4.14 10.42 0.40 39.71

4 3.0 23.3 16.1 10.9 8.2 5.8 3.8 3.4 2.23 5.64 0.40 39.55

6 5.0 29.7 20.5 13.8 6.4 4.4 2.9 2.7 1.69 4.36 0.39 38.89

8 7.0 35.4 24.6 16.3 5.7 4.1 2.5 2.4 1.46 3.83 0.38 38.12

10 9.0 40.9 28.4 18.7 5.5 3.8 2.4 2.3 1.40 3.69 0.38 38.00

15 12.5 53.9 37.3 24.5 13.0 8.9 5.8 5.4 3.39 8.79 0.39 38.52

20 17.5 65.4 45.4 30.6 11.5 8.1 6.1 4.8 3.56 8.35 0.43 42.69

30 25.0 82.3 59.1 42.9 16.9 13.7 12.3 7.0 7.18 14.21 0.51 50.55

40 35.0 91.2 69.1 53.9 8.9 10.0 11.0 3.7 6.43 10.13 0.63 63.45

60 50.0 97.7 80.5 70.0 6.5 11.4 16.1 2.7 9.40 12.11 0.78 77.67

90 75.0 99.7 90.3 83.8 2.0 9.8 13.8 0.8 8.06 8.89 0.91 90.65

100 95.0 99.8 92.1 86.8 0.1 1.8 3.0 0.0 1.75 1.79 0.98 97.68


t/h 30 µm 40 µm 60 µm 90 µm 200 µm

calc. F/A 0.4159 final 22.2 1.2 0.3 0.0

G/F 0.5841 feeding 53.4 13.9 11.8 4.7 0.3

coarse 31.2 19.6 17.2 6.9 0.4


Soutirage % 38.8

Ord.Sep.diam % 48


22.2

CEM I 52.5 R

Wyss 3.2 x 14.0

Test no.

492

Wedag ZUB 32

Date

Cement Type

Production t/h

Spec.surf. M2/kg

with MA.P.E./S 5

Cement Plant

Mill

Separator


T separation curve

MApei PerformanceEnhancer/WPack set inhibitors,strengths and flow enhancers

DESCRIPTIONMA.P.E./W are highly concentrated grinding aidsformulated with only selected raw materials, toguarantee absolute constancy of quality and superiorperformance.

They are additives formulated to improve cementquality (early and/or ultimate strengths, flow) and toaid cement grinding, increasing mill production.

TECHNICAL CHARACTERISTICSMA.P.E./W also guarantee, besides all theadvantages which come from the usage of thegrinding aids (refer to MA.G.A./C), remarkableincrements in early and ultimate strengths and an improvement of the workability (flow) of thecement paste.

At equal fineness MA.P.E./W are able to increasemechanical strengths thank to a better granulometricredistribution of the finished cement and to a higherrate of calcium silicates hydration, which can besignificantly modified.

APPLICATION PROCEDUREMA.P.E./W may be successfully utilized in thegrinding of blended cements, (i.e. pozzolanic, blastfurnace slag and fly ash cements) and in all caseswhere it is necessary to improve the cement flow.

MA.P.E./W are generally formulated to reach the

goals placed by the cement factory. The achievablestrength increment may be used to improve thequality of the binder or, keeping cement qualityunaltered, it is possible to substitute in the mixtureup to 4-6% of clinker with blended material.

In normal conditions the strength increases are in the range of 20-50% after one day and 5-15% after28 days.

The formulations, which are specifically orientedtowards improving the water demand of the cement,especially used in the production of pozzolaniccements, allow increases to the flow of up to even 20 points (UNI standard 7044-72).


DOSAGE1.0-3.0 kg/t.We suggest the higher dosage threshold, if the aim is the substitution of clinker points with blendedmaterial (i.e. blast-furnace slag, fly ash, pozzolan) orthe reduction of the water demand of the cement.

The optimum dosage has, in any case, to be found through a reliable industrial trial, preferablywith the help of MAPEI Cement Additives Divisiontechnicians.

MA.P.E./W

MA.P.E./W

79

tttt

tt




2. TRIAL RESULTS




3. CONCLUSIONS

Industrial Trial Report on the productionof CEM IV/B-P 32.5 R using the Mapeigrinding additive MA.P.E./W1

INDUSTRIAL TRIAL WITH MA.P.E./W1

80


The grinding circuit is particularly interesting in that it consists of two mills and a mixer. Pozzolana is dried and ground in a Löesche LM24 vertical mill and is then stored in an interme-diate silo.

Clinker and gypsum are ground in a Fema tubular ball mill, Ø 3.8 x 13.75m in a closed circuit con-sisting of a 3° generation Humboldt separator, Ø 3.5 m with 4 cyclones. The gases exiting fromthe mill are filtered by means of a bag filter. The grinding additive is added to the first chamber ofthe ball mill.

A mixer receives and homogenises the cement (clinker & gypsum) coming from the ball mill andthe pozzolana coming from the intermediate silo, thus producing the finished CEM IV/B-P 32.5 Rcement.

The power absorption of the principle machines are as follows:

Löesche vertical mill: 465 kWFema tubular ball mill: 1.990 kW Humboldt separator: 98 kW

b) Trial Description and Additive Selection

An industrial evaluation of the grinding additive MA.P.E./W1, a liquid product for the productionof Pozzolanic cements specifically formulated with raw materials of the highest quality.

MA.P.E./W1 is an additive with a triple action, developed to increase the workability and mecha-nical strengths of the ground cement as well as ensuring high mill productivity.

The trial consisted of grinding a CEM IV/B-P 32.5 R cement at the same level of fineness, withand without the addition of MA.P.E./W1, verifying immediately the effects on mill productivity andsuccessively on workability, mechanical strengths and separation performance.


81


On examination of Table A, it is possible to see that the addition of MA.P.E./W1 has produced anincrease in productivity of 11.8% with relevant energy savings. This confirms the product’s validgrinding aid characteristics.

Industrial Trial Data

0.0

20.0

40.0

60.0

80.0

100.0

Productivity (t/h) Energy Consumption

(kWh/t)

Blank MAPE/W 10..0100

0..080

0..060

rial DataIndustrial T

Blank MAPE/W 1

rial Data

MAPE/W 1

0..040

0..020

0..00

Productivity (t/h)

(kWh/t)

Energy Consumption

2. TRIAL RESULTS

Details Units Blank MA.P.E./W1Cement Type CEM IV/B-P 32.5 R CEM IV/B-P 32. 5 RAdditive dosage g/t --- 2.700Production t/h 83.9 93.8Passing material at 40 µm. % 80 81.5Passing material at 63 µm. % 94 95Specific Mill & Separator Consumption kWh/t 30.4 27.2Workability Flow 36 48Strengths at 24 hours MPa 8.0 10.6Strengths at 2 days MPa 16.3 18.5Strengths at 28 days MPa 34.9 40.3

Table A

83.993.8

30.4 27.2

82

Workability

The utilisation of the additive increases the workability by 12 points equivalent to 33.3%.

b) Post Trial AnalysisStrengths

Strength testing was conducted in accordance with the European standard EN 196-1. The utilisation of the additive increases the strengths of the cement as follows: + 32.5% at 24 hours, + 13.5% at 2 days and + 15.5% at 28 days.


0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

45.0

1 day 2 days 28 days


0..040

0..035

0..030

0..025


Blank MAPE/W 1


MAPE/W 1

0..020

0..015

0..010

0..05

0..00

2 days1 day 28 days

Cement Flow

20.0

30.0

40.0

50.0

60.0

Flow


0..050

040

Cement Flow

Blank MAPE/W 1

Cement Flow

MAPE/W 1

0..040

0..030

0..020

Flow

8.0 10.6

16.3

18.5

34.9

40.3

36.0

48.0

83c) Technical Analysis

During the industrial trial samples of the following materials were taken:

Separator feed Separator finished productRecycle from separatorFinished cement

The samples were subjected to laser and Alpine granulometric particle distribution analysis.In Table B the results of the separator yield, the Tromp curve and the R.R.B. regression line equa-tion are reported.

The results indicate the separator’s (3° generation) good level of separation efficiency in both con-ditions of operation.It is interesting to observe how the utilisation of the additive leads to a significant reduction of thecirculating load from 4.1 to 3.0. Mill grinding has improved and the cement particles are lessagglomerated. In addition there is a substantial reduction in the quantity of the material which by-pass the separator without being classified, passing from 41.5% without an additive (blank) to18.8% with the additive.As regards the investigations conducted on the cement, tracing the R.R.B. regression line we donot find substantial differences except a minimal increase in the slope of the line and a minimalreduction of the particle distribution curve when the additive is utilised.

Details Units Blank MA.P.E./W1Cement Type CEM IV/A 32.5 R CEM IV/A 32. 5 RAdditive dosage g/t --- 2,700Circulating load A/F 4.1 3.0Soutirage (by-pass) % 41.5 18.8Diameter of separation µm 45 37Inclination of the 2° branch of the curve ° 56 56Efficiency evaluation Good GoodAngle R.R.B line ° 45.2 45.7Characteristic diameter (res. 36,8%) µm 29.4 28.4

Table B

84

blaine

laser


2 1.0 6.9 3.1 2.0 6.9 3.1 2.0 1.69 1.51 3.20 47.2

4 2.0 13.8 6.2 3.8 6.9 3.1 1.8 1.69 1.36 3.05 44.6

8 5.0 27.1 11.6 6.7 13.3 5.4 2.9 3.26 2.19 5.45 40.2

10 7.0 33.4 14.1 7.9 6.3 2.5 1.2 1.54 0.91 2.45 37.0

15 11.5 47.9 20.0 10.6 14.5 5.9 2.7 3.55 2.04 5.59 36.4

20 15.0 59.4 25.2 13.5 11.5 5.2 2.9 2.82 2.19 5.01 43.7

30 22.5 74.1 33.0 19.1 14.7 7.8 5.6 3.60 4.23 7.83 54.0

40 30.0 85.7 41.6 26.6 11.6 8.6 7.5 2.84 5.66 8.50 66.6

60 45.0 93.0 55.9 43.6 7.3 14.3 17.0 1.79 12.83 14.62 87.8

90 65.0 96.8 69.0 62.0 3.8 13.1 18.4 0.93 13.89 14.82 93.7



calc. F/A 0.245 final 94.0 300 14.5 7.5 1.5 0.0 0.0

G/F 0.755 feeding 383.0 157 58.3 49.2 21.3 10.1 1.0

coarse 289.0 104 78.4 66.7 31.0 14.2 1.0


Mayer's Min. Ord. (S) % 36.4 Efficiency Evaluation =(Sep. Line angle)

Soutirage % 41.5 Imperfection ad 0.24

Sep.diam µm 45


Intermediate

342

411

93.8

Description

Cement Type

Production t/h

Spec.surf. M2/kg

Good

Cement Plant

Mill

Separator

Test no.


FEMA 3.8 x 13.75

Humboldt

Blank Grinding

T (%) corr

16.9

12.8

5.9

0.8

0.0

11.4

27.6

47.4

80.7

90.1

Tromp Curve according to Mayer

85

blaine

laser


2 1.0 6.8 2.9 1.1 6.8 2.9 1.1 2.23 0.74 2.97 24.8

4 2.0 13.3 5.7 1.9 6.5 2.8 0.8 2.14 0.54 2.67 20.1

8 5.0 24.7 10.1 2.9 11.4 4.4 1.0 3.75 0.67 4.42 15.2

10 7.0 29.7 11.9 3.3 5.0 1.8 0.4 1.64 0.27 1.91 14.0

15 11.5 41.3 16.4 4.5 11.6 4.5 1.2 3.81 0.81 4.62 17.4

20 15.0 51.8 21.0 5.9 10.5 4.6 1.4 3.45 0.94 4.39 21.4

30 22.5 68.1 29.8 10.7 16.3 8.8 4.8 5.36 3.22 8.58 37.6

40 30.0 82.4 40.4 19.9 14.3 10.6 9.2 4.70 6.18 10.88 56.8

60 45.0 93.1 60.7 43.7 10.7 20.3 23.8 3.52 15.98 19.50 82.0

90 65.0 97.2 77.2 68.5 4.1 16.5 24.8 1.35 16.65 18.00 92.5



calc. F/A 0.329 final 94.0 300 14.5 7.5 1.5 0.0 0.0

G/F 0.671 feeding 285.0 157 58.3 49.2 21.3 10.1 1.0

coarse 192.0 104 78.4 66.7 31.0 14.2 1.0


Mayer's Min. Ord. (S) % 14.0 Efficiency Evaluation =(Sep. Line angle)

Soutirage % 18.8 Imperfection ad 0.39

Sep.diam µm 37

79.0

91.3

4.0

8.6

27.4

49.7

12.6

7.0

1.3

0.0

Humboldt

Grinding with MA.P.E./W 1 (0.27%)

T (%) corr

Production t/h

Spec.surf. M2/kg

Good

Cement Plant

Mill

Separator

Test no.


FEMA 3.8 x 13.75


Intermediate

342

411

93.8

Description

Cement Type

Tromp Curve according to Mayer

86

blaine

laser

dim.µm pass. (%) res. (%)

1 2.8 97.2 30 µm 40 µm 60 µm 90 µm 200 µm

2 6.6 93.4 Residue (%) 26.5 20.0 6.0 1.0 0.0

4 13.0 87.0

6 18.9 81.1 Linear Regression Y = a + n x

8 24.3 75.7

10 29.2 70.8 Uniformity Coe (n) 1.0075 Line coordinates

15 40.6 59.4 Cross (a) -3.4078 X(µm) Y(% R) 100-R

20 50.2 49.8 Line Angle (Gr) 45.2 1 96.7 3.3

30 62.3 37.7 Charact. Diam. (Xo) 29.4 µm 29 36.8 63.2

40 73.1 26.9 Res. 36,8% 90 4.6 95.4

60 84.0 16.0

90 94.4 5.6

100 97.3 2.7

Notes


296.7

419.7

Description


Mill

Separator

Test no.

Pozzolanic CEM IV/B-P 32.5 R

Humboldt Ø 3.5m

Blank Grinding

Sample

Spec.surf. M2/kg

FEMA 3.8x13.75m; Loesche Ø 2.4m


87

blaine

laser

dim.µm pass. (%) res. (%)

1 2.8 97.2 30 µm 40 µm 60 µm 90 µm 200 µm

2 6.7 93.3 Residue (%) 25.0 18.5 5.0 1.0 0.0

4 13.0 87.0

6 18.9 81.1 Linear Regression Y = a + n x

8 24.5 75.5

10 29.6 70.4 Uniformity Coe (n) 1.0240 Line coordinates

15 41.5 58.5 Cross (a) -3.4357 X(µm) Y(% R) 100-R

20 51.5 48.5 Line Angle (Gr) 45.7 1 96.8 3.2

30 64.7 35.3 Charact. Diam. (Xo) 28.4 µm 28 36.8 63.2

40 76.0 24.0 Res. 36,8% 90 3.8 96.2

60 86.5 13.5

90 95.4 4.6

100 97.5 2.5

Notes

Grinding with MA.P.E./W 1 (0.27%)

Sample

Spec.surf. M2/kg

FEMA 3.8x13.75m; Loesche Ø 2.4mMill

Separator

Test no.

Pozzolanic CEM IV/B-P 32.5 R

Humboldt Ø 3.5m


296.7

419.7

Description



88

The results obtained from the industrial trial have confirmed the triple action of the additiveMA.P.E./W1 and continuous utilisation of this product gives the following benefits:

• Increases in productivity, especially in the periods when energy costs are lower ensuring signi-ficant energy savings.

• Cement mechanical strength increases.

• An increase in the workability of the cement. The inferior water demand reduces the consum-ption of cement and helps the synergy with plasticizer additives employed in the production ofconcrete.

3. CONCLUSIONS

MApei PerformanceEnhancer/AGrinding aids formasonry cement

DESCRIPTIONMA.P.E./A are air-entraining agents formulated forgrinding of artificial and natural hydraulic masonrycements.

Artificial hydraulic masonry cements are obtained by the grinding of clinker (15/40%) together with one or more inert materials (limestone or siliceous).Natural hydraulic masonry cements are obtained byfiring natural marls at +900°C, and are characterizedby low mechanical strengths, but have a pastyconsistency, high workability and adhesiveness.

MA.P.E./A confer to artificial hydraulic masonrycements characteristics similar to those of thenatural ones (workability, adhesiveness, resistance to frost-thaw cycles, etc). MA.P.E./A can also further improve the performance of natural hydraulicmasonry cements. Specific formulations ofMA.P.E./A also allow mill output increases.

Masonry cement evaluation is principally based onair entrapment (>10%) and water retention (> 85%)potential.

These characteristics guarantee better workability,yield and durability of the cement.

TECHNICAL CHARACTERISTICSMA.P.E./A have both air entraining and waterretention actions. Air entraining can reach 15 to 18%

improving the workability of the product. Waterretention can easily exceed 95% (based on ASTMstandards).

Air is entrained in micro-bubbles, homogeneouslydistributed, improving workability, yield per surfaceunit and resistance to freeze-thaw cycles. Micro-bubbles, with controlled diameter and high stability,act as a lubricant between mortar layers, improvingflow and workability.

Water retention prevents the mortar mixing waterfrom migrating towards the external substrate,improve adhesiveness and helps avoid crackformation. Regular water content in the mortar allowsa homogeneous and controlled hardening.

APPLICATION PROCEDUREMA.P.E./A are formulated to improve thecharacteristics of natural and artificial hydraulicmasonry cements. They are to be added to the millduring the grinding phase for a correct dispersionand to maximize the performance.

CHEMICAL-PHYSICAL DATA Please refer to the appropriate safety data sheets.

DOSAGE0.6-1.0 kg/t.The optimum dosage depends on the type andfineness of the masonry cement.

MA.P.E./A

MA.P.E./A

MApei PerformanceEnhancer/Cr 05Cr(VI) Reducing Additive

DESCRIPTIONMA.P.E./Cr 05 is a chromate reducing agent,formulated with selected raw materials, ensuring an elevated and constant quality.

MA.P.E./Cr 05 is a liquid additive which has to be added to the mill during the cement grindingprocess. It ensures the production of cementswithout Cr(VI), according to European obligation2003/53/EC.

TECHNICAL CHARACTERISTICSMA.P.E./Cr 05 guarantees, besides advantagescoming from the usage of a liquid product, anefficient and stable reduction of soluble chromates in cement and hydraulic binders.

It is an absolutely innovative liquid product, based on antimony*, dispersed on to clinker and other rawmaterials during the grinding of cement. Duringcement hydration the reducing agent acts on soluble chromates, transforming Cr(VI) into Cr(III).

In comparison with traditional Cr(VI) reducingadditives, MA.P.E./Cr 05 has an alkaline pH.

APPLICATIONSMA.P.E./Cr 05 can be successfully employed incement or hydraulic binders and in general whereverit is necessary to reduce Cr(VI).

The additive must be used only during grinding,added on to the clinker conveyor belt or directly infirst chamber. In any case it should be added asclose as possible to the mill entrance, avoiding longand complicated distances which could cause a lossof additive before mill entrance.

It is recommended to avoid mixing MA.P.E./Cr 05with grinding aids normally employed in cementfactories.

Under normal cement storage conditions andapplying a dosage based on grinding plantconditions, the reducing action shall remainunchanged for at least six months.

CHEMICAL-PHYSICAL DATAPlease refer to the appropriate safety data sheets.The dosage depends on Cr(VI) cement content andplant type. Generally speaking we suggest a dosagebetween 50 and 55 g/t for each ppm of Cr(VI)existing in cement.The optimum dosage, in any case, has to be foundthrough a reliable industrial trial, preferably with thehelp of MAPEI Cement Additives Divisiontechnicians.

DOSAGEMA.P.E./Cr 05 can be dosed by means of peristaltic or membrane pumps.

MA.P.E./Cr 05

MA.P.E./Cr 05

93

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SCIENTIFIC BACKGROUND

(Previously published in ZKG-

Magazine)

MA.P.E./Cr 05: Industrial case studies

and economical considerations

MA.P.E./Cr 05

The liquid revolution

94Thanks to intensive Research, D.A.M. developed a new, liquid and now patented technology forthe reduction of Cr(VI) in cement, with numerous advantages in terms of technical functionality,practical application and economic impact.

In fact, MA.P.E./Cr 05 allows cement manufacturers to guarantee their customers extremely longlasting Cr(VI) reduction (up to 12 months), even in extreme conditions (like cement transport bysea) and without any negative effects in concrete applications. The advantages for the cementmanufacturers themselves, however, are confirmed in terms of material handling (the product hasa neutral pH), application (dosing a liquid product is much easier than powder compounds) andcosts (the product is to be dosed stoichiometrically which allows it to be competitive in certaincases, even with Ferrous Sulfate).

SCIENTIFIC BACKGROUND (Previously published in ZKG-Magazine)

Hexavalent chromium in cementThe raw material for grey Portland cement manufacturing may contain chromium. Due to the highlyoxidizing and alkaline conditions of the kiln, during clinker production chromium is partially con-verted to hexavalent chromium and probably fixed as alkaline or calcium chromate (Na2CrO4,K2CrO4, CaCrO4). As a result, Portland clinkers and cements contain soluble chromates (usually inthe range of 5 – 20 ppm or mg/kg, while the total chromium may reach 200 ppm) which are repor-ted to cause skin irritation (allergic contact dermatitis). This is the reason why the EuropeanCommunity has introduced the obligation (Directive 2003/53/EC) to maintain the level of solublechromates below 2 ppm. This has a significant economical impact on the cement industry.

The reduction of soluble chromates: iron(II) and tin(II) saltsWhile Cr(VI) is a strong oxidising agent in acid solution, in an alkaline media (such as the cementmixing water) the situation is completely different and it is impossible to reduce the Cr(VI) withmost of the reducing agents which usually work at pH lower than 7. The reason lies in the factthat the red-ox potential of the couple Cr(VI)/Cr(III) changes with pH. Using the Nernst equationit is possible to calculate the value of red-ox potential at different pH and evaluate, from a ther-modynamic point of view, which red-ox couple can reduce Cr(VI) to Cr(III) [1].The reduction of soluble chromates is usually obtained with the addition of ferrous or stannoussalts (in powder or in the form of liquid additives) during cement grinding. Both iron and tin formpoorly soluble hydroxides in alkaline media, and this lowers the red-ox potential of the couplesFe(III)/Fe(II) and Sn(IV)/Sn(II), allowing the reduction of Cr(VI) to Cr(III) according to the followingequations:

1) CrO42- + 3Fe(OH)2 + 4H2O = Cr(OH)3 + 3Fe(OH)3 + 2OH-

2) 2CrO42- + 3Sn(OH)2 + 2OH- + 8H2O = 2Cr(OH)3 + 3Sn(OH)62-

The mechanism of action of ferrous and stannous salts can be considered as follows:• as soon as the cement (ground with the reducing agent) is mixed with water, chromates andferrous/stannous salts are released in solution, while the pH quickly increases following thehydration of cement;• Fe2+ and Sn2+ ions form insoluble hydroxides, their red-ox potential drop (in particular as the pH

95increases, their red-ox potential drop faster than the red-ox potential of Cr6+) and the Fe(OH)2 andSn(OH)2 become strong reducing agents;• soluble chromates are reduced to Cr(OH)3.

In Table 1 the red-ox potential of Cr(VI)/Cr(III), Fe(III)/Fe(II) and Sn(IV)/Sn(II) in alkaline solution arereported [2]: the lower is the red-ox potential, the higher is the reducing power of the couple.Both ferrous and stannous salts present advantages and disadvantages. Ferrous sulphate (available in different hydrated forms) is very cheap, but presents serious pro-blems related to the durability of the reducing properties: it is very sensitive to moisture and tem-perature and tends to loose efficacy after grinding and during cement storage. This requires theuse of very high dosages of ferrous sulphate, with costs higher than expected and undesiredeffects (spots on the concrete surfaces, due to the red colour of Fe3+ compounds, are reported). In our opinion, the poor durability of iron(II) reducing agents can be explained considering the acidcharacter of iron and the presence of water of crystallisation. We can suppose that ferrous sul-phate may react during cement grinding (or storage) with very alkaline free lime, being partiallyconverted to ferrous hydroxide according to the following acid-base reaction:

3) FeSO4·7H2O + CaO = Fe(OH)2 + CaSO4 + 6H2O

If ferrous sulphate is converted before having soluble chromates available for reduction, due tothe strong reducing properties, ferrous hydroxide is readily oxidised by oxygen and looses it’sreduction ability.

Stannous sulphate has a superior reduction capacity (allowing very low dosages) and no undesi-red effects, but is very expensive. Recently it has been reported [3] that in presence of highamounts of free lime and moisture, stannous compounds partially loose their reduction ability. Thisis more evident with liquid additives based on tin(II) compounds (stannous chloride or sulphate), inparticular with stannous sulphate aqueous solutions, as reported elsewhere [4]. The reason, asexplained for iron(II), can lie in the fact that tin(II) has strong acid properties, and during cementgrinding it can react with free lime and water being partially converted to stannous hydroxide:

1) SnSO4 + CaO + H2O = Sn(OH)2 + CaSO4

2) SnCl2 + CaO + H2O = Sn(OH)2 + CaCl2

The stannous hydroxide, due to its very low red-ox potential, is unstable and, if no soluble chro-mates are present, is immediately oxidised by oxygen or water or spontaneously converts to

Red-ox couple Half-reaction Red-ox potential in alkaline solution E (Volt)

Cr(VI)/Cr(III) CrO42- + 3e- + 4H2O = Cr(OH)3 + 5OH- -0.12

Fe(III)/Fe(II) Fe(OH)3 + e- = Fe(OH)2 + OH- -0.56Sn(IV)/Sn(II) Sn(OH)62- + 2e- = Sn(OH)2 + 4OH- -0.96

Table 1

96tin(IV) and metallic tin. This behaviour is summarized in the Pourbaix diagram of tin [5], thatreports the stability range of several tin compounds in function of pH and red-ox potential (Figure1). It is possible to see that, as the pH increases, the stability area of Sn(OH)2 is reduced and,above pH=12, only Sn4+ and metallic tin are stable. As a result, in some cases higher tin dosagesare required, with negative effects on costs and durability of reducing properties. The reactions 4and 5, in order to proceed, require the presence of water. This may be the reason why stannoussulphate in powder is more efficient than water-based liquid formulations containing tin salts.

A brand new technology: antimony(III) compoundsA very promising and innovative class of reducing agents (at the moment object of an internatio-nal patent application by Mapei SpA) has recently been studied and developed in Mapei R&D lab.The efficacy and the superior performances of this novel class is based on the red-ox propertiesof antimony(III). The couple Sb(V)/Sb(III), has a red-ox potential in alkaline solution E=-0,59 volt [2].From a thermodynamic point of view, this means that Sb(III) is a strong reducing agent at high pHand can reduce Cr(VI) present in the cement mixing water, according to the following equation:

6) 2CrO42- + 3H2SbO3

- + 2H2O = 2Cr(OH)3 + 3SbO3- + 4OH-

The Pourbaix diagram of antimony [5], reported in Figure 2, shows that the Sb(III) is stable at alka-line pH. In comparison to ferrous and stannous salts, Sb(III) compounds have weaker acid pro-perties. This is an interesting advantage, because the reaction with free lime does not proceed,

Figure 1: Pourbaix diagram of tin. The red area represents the pH range of cementmixing water. The variation of red-ox potential of oxygen and hydrogen are pointed out

E (volt) 2.0

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97avoiding any efficacy loss during cement grinding or storage, even in case of high free lime con-tent and high level of humidity. As a result, the reduction performance of antimony(III) is unaffected by moisture and high grin-ding or storing temperatures. The reducing properties of antimony(III) remain unchanged evenafter more than one year.

Antimony(III) in a liquid additive: MA.P.E./Cr 05The formulation of a liquid additive based on antimony(III) for the reduction of hexavalent chro-mium requires the selection of the most appropriate Sb(III) compound. This should be:

• easy to incorporate in a water-based formulation;• with an economical impact inferior to tin-based liquid additives; • no effect on the properties and quality of the cement.

Most of all, in order to maintain it’s reduction ability safe for as long as possible, the reducingagent should remain unaltered during the storage of the additive and, after being added in themill, during the storage of cement. Strong reducing agents (like ferrous or stannous salts) are rea-dily oxidised by oxygen (or directly by water, as described for stannous hydroxide), and high tem-peratures and high levels of humidity (e.g. presence of coordination water, as in the case of fer-

Figure 2: Pourbaix diagram of antimony. The red area represents the pH range ofcement mixing water. The variation of red-ox potential of oxygen and hydrogen arepointed out

E (volt) 1.0

0.5

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98rous sulphate) speed up the reaction. If it was possible to activate the reducing agent only whencement is mixed with water (when soluble chromates are available for reduction), we would obtainan excellent improvement of shelf life and durability after prolonged storage. We have found that it is possible to reach all the targets using a liquid additive based on antimo-ny trioxide. This compound is amphoteric: it is soluble only at very low or very high pH and iscompletely insoluble at medium pH. A liquid additive with high load of insoluble particles of anti-mony trioxide can be easily prepared by using the well-known technology of solid liquid disper-sion, widely used in several industrial sectors (ceramic, polymers, textile, paints, paper, cosme-tics and pharmaceutical, detergents) [6].The principle of action is now clear: the antimony trioxide is dispersed in to the cement by sim-ply dosing the liquid additive on to the clinker conveyor belt and ground in the mill. Thanks to itsinsolubility and low acidity, it is not modified by water or free lime and it remains unaltered untilcement is mixed with water: at pH higher than 12 the antimony trioxide is dissolved in water andis fully available to reduce the Cr(VI) released in water.

The advantages of MA.P.E./Cr 05 are the following:

• neutral (or alkaline) pH, while other liquid additives based on tin have strong acid pH and arehighly corrosive.• No recrystallisation of partially solubilised salts (the active component is completely insoluble)and consequently no formation of precipitate and difficulties in pumping. • No reducing agent lost, in any mill conditions (high amount of cooling water, high temperature).This allows the cement plant to avoid any extra dosage, as usually happens with ferrous sulpha-te and sometimes with tin-based liquid reducing agents.• No reducing agent lost during storage: this allows to maintain constant the Cr(VI) content for avery long time, without requiring an over dosage.

Case studyIn order to check the reduction performance of MA.P.E./Cr 05, the following laboratory test hasbeen performed. The performances of ferrous sulphate, stannous sulphate and MA.P.E./Cr05 (aliquid suspension of antimony trioxide, with 20% active matter), have been compared. A cementhas been reproduced in a laboratory mill by grinding clinker and gypsum. A clinker with a veryhigh level of free lime has been chosen (free CaO = 1.78%). The amount of soluble Cr(VI) relea-sed in water (without reducing agent) is 10 ppm. The same cement has been reproduced by grin-ding with the reducing agents reported in the table 2.

The samples of cement have been stored in the same conditions and the soluble Cr(VI) contenthas been evaluated for a period of six months, using the following method: 100 g of cement are

Reducing agent Dosage (weight % over Dosage (g/t) for each ppm cement weight) of Cr(VI)

Ferrous sulphate 0.200 % 200 g/t·ppm(FeSO4·7H2O)

Stannous sulphate 0.020 % 20 g/t·ppm(SnSO4)

MA.P.E./Cr 05(20% water suspension 0.045 % 45 g/t·ppm

of Sb2O3)

99added to 100 g of water. After magnetic stirring for 15 minutes, the water is filtered off and ana-lyzed by ionic chromatography (see [7] for details). The results are summarized in the graph 1.It can be clearly seen that with this cement (characterised by a high content of free lime) the stan-nous sulphate is effective only for a limited period of time: after two months the soluble Cr(VI)content exceeds the limit of 2 ppm. The ferrous sulphate at a dosage commonly used (0,2%) isunable to eliminate Cr(VI). The performances of antimony trioxide (MA.P.E./Cr 05) are clearlysuperior: the Cr(VI) level is close to zero even after several months. On an industrial scale, the results are similar. In addition it is possible to see that the economicalincidence of such an additive is lower than the incidence of stannous sulphate and sometimescan be similar to that of ferrous sulphate.

ConclusionsThe use of antimony(III) compounds for the reduction of hexavalent chromium in cement andcement based materials presents interesting advantages: 1. Due to the high stability and low acidity of antimony(III), these reducing agents are insensitiveto temperature and humidity and are not affected by the presence of high levels of free lime. Thisallows superior performances to be obtained in comparison to the usual reducing agents basedon ferrous or stannous salts. 2. Antimony(III) compounds can also be used for the formulation of liquid additives. If antimonytrioxide is dispersed in water (using well known technologies), it is possible to obtain a stablesuspension that can be dosed during cement grinding as a liquid additive. Thanks to its ampho-teric properties, the antimony trioxide remains unchanged on the surface of cement and is acti-vated only when the cement is mixed with water and the pH rises above 12. This theoreticallyallows to maintain the efficacy of the reducing agent for an infinite time.3. The MA.P.E./Cr 05, a liquid additive formulated according to this new technology, shows supe-rior performances in comparison to iron and tin based reducing agents.

Graph 1: results of lab test about reducing agents

day days days days days month months months months

Ferrous sulphate0.2%

Stannous sulphate

100

Industrial useIn lab test the dosage of MA.P.E./Cr 05 is about 50 g/t for each ppm of Cr(VI) to be reduced.During industrial trials dosages sometimes are lower, in the range 40 - 45 g/t for each ppm ofCr(VI). This difference is probably related to a better dispersion of the product in cement, allowedby industrial milling. MA.P.E./Cr 05 should be dosed directly on the clinker/feed conveyor belt using a peristaltic or apiston pump, with a dedicated pipeline. MA.P.E./Cr 05 should be stored avoiding contaminationwith different products (e.g. grinding aids, reducing agent based on tin).MA.P.E./Cr 05 is a very stable suspension, so it doesn’t need additional mixing system to avoidsolid particles sedimentation.The picture below shows a typical industrial application:

How to use MA.P.E./Cr 05It is important to point out that, thanks to the long term stability, it is not necessary to reducecompletely the hexavalent chromium present in cement. MA.P.E./Cr 05 can be dosed in order toreach a Cr(VI) level of about 1 ppm. This value will usually be maintained even after severalmonths, which allows interesting cost savings.MA.P.E./Cr 05 has a great Cr(VI) reducing effect on any type of cement, as shown in Table 2.

MA.P.E./Cr 05: Industrial case studies and economicalconsiderations

Table 2: efficacy of MA.P.E./Cr 05 on different cementsCement type Cr(VI) Dosage Cr(VI) Cr(VI) after 6 monthsCEM I 52.5 R 22.3 ppm 1.02 kg/t 1.1 1.1CEM II/A-LL 42.5 R 10.3 ppm 0.45 kg/t 1.0 1.0CEM II/B-S 32.5 R 7.6 ppm 0.29 kg/t 0.9 0.9CEM II/B-M (LL-P) 32.5 R 6.0 ppm 0.23 kg/t 0.8 0.8CEM III/A 32.5 N 4.4 ppm 0.17 kg/t 1.0 1.0CEM IV/B-P 32.5 R 5.7 ppm 0.22 kg/t 1.2 1.2

101Comparison with stannous sulphate Stannous sulphate is a widespread Cr(VI) reducing agent, available in both powder and liquidform. Usually, the powder is more difficult to handle and to dose accurately than the liquid pro-duct. The average dosage of stannous sulphate is 15 g/t for each ppm of Cr(VI) and guaranteesa Cr(VI) reduction for several months. Stannous sulphate prices have increased very much in thelast few months. At the moment we can consider a price of around 8 - 9 €/kg.

Industrial case n°1A CEM I 52.5 R is produced with 5000 cm2/g Blaine fineness, with a mill productivity of 48 t/h.The hexavalent chromium content of this cement is about 13 ppm. The reducing agent used isstannous sulphate (powder form) at a dosage of 15 g/t·ppm. MA.P.E./Cr 05 was tested in com-parison to stannous sulphate. As summarized in Table 3, it has been possible to dose MA.P.E./Cr 05at 48 g/t*ppm, allowing a 17% cost saving.Compared to stannous sulphate MA.P.E./Cr 05 presents the following advantages:

• Technical advantages: easy dosing and pumping • Economical advantage: cost savings in the cement production process (-17,3%)

Considering the use of stannous sulphate-based liquid additives, it is possible to overcome thedifficulties in handling a powder, but the economical impact is obviously higher, sometimes even40 – 50% higher than MA.P.E./Cr 05.

Comparison with iron sulphateIron sulphate is available only in powder form. It is commonly employed in cement plants in spiteof the following technical problems:

• Unstable product: over dosage is necessary in order to guarantee Cr(VI) reduction for at least 3months.• Dosing system: difficult and expensive handling. • Side effects: possible red/dark spots on concrete surface.

The very low price is the only advantage of iron sulphate, even if this is not always true: someti-mes the economical impact of MA.P.E./Cr 05 has been found lower (or comparable) than iron sul-phate. The following example describes one of our practical experiences.

Industrial case n°2An Italian cement plant produces a CEM II/A-LL 42,5 R (80% clinker, 15% limestone, 5% gyp-sum) with Cr(VI) content of 5 ppm. To reduce and maintain the level of Cr(VI) constant for three

Table 3: industrial case - comparison with stannous sulphateStannous sulphate MA.P.E./Cr 05

Price (€/kg) 8.5 2.2Dosage (g/t*ppm of Cr(VI) 15 48Dosage (g/t) 195 624Economical impact (€/t) 1.66 1.37Differences (%) // -17.3%

102months, iron sulphate is used at a dosage of 1.5 kg/t (0.15%) of cement produced. The price ofiron sulphate is 0.14 €/kg (including delivery costs) so its economical impact is 0.21 €/t of cement. Several dosages of MA.P.E./Cr 05 were tested in order to clarify the economical impact.Considering that no overdosing is needed, it is not necessary to reduce Cr(VI) completely: theindustrial trial was performed in order to have a final Cr(VI) content of 1 ppm. Graph 1 shows thatMA.P.E./Cr 05 dosed at about 100 g/t has the same economical impact as iron sulphate. Anydosage below this value means lower economical impact and allows to maintain the level of Cr(VI)below 2 ppm even for several months.

Conclusions1. MA.P.E./Cr 05 is a new liquid additive for Cr(VI) reduction in cement and cement based materials. 2. Thanks to the properties of its active ingredient (antimony trioxide), MA.P.E./Cr 05 shows supe-rior performances in comparison to iron and tin based products. 3. In most cases, the use of MA.P.E./Cr 05 allows lower economical impact (in terms of euro foreach ton of cement produced), with technical performances comparable (or superior) to otherreducing agents.

Graph 1: industrial case - economical impact of MA.P.E./Cr 05 in comparison to ironsulphate.Pink line: ppm of Cr(VI) residual. Blue line: economical impact of MA.P.E./Cr 05 (€/t)Red line: economical impact of iron sulphate

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Cement Grinding Additives Division

Since 2008 DAM is part of Mapei’s Liquid Admixtures Division. This division has been formed in order to optimise the synergy between the various stages of the building process of any type of structure: Cement Manufacturing - Concrete Application - Terrain Decontamination - Underground Technology. Through joint projects in terms of Research & Development, Technical Customer Assistance and Product Development, knowledge is shared and products and services are improved. Within the Liquid Admixture Division special attention is paid to the reduction of CO2 emissions and the limitation of the use of non-renewable resources. In this specifi c fi eld of interest, DAM is offering various specifi c solutions to the cement industry for the reduction of both clinker content and the specifi c energy consumption during the production of cement.

Mapei Spa, since 1995 has enforced theQuality System certifi ed according toUNI EN ISO 9001. The program also entailed the ISO 9001 certifi cation of many other subsidiaries in the Group

Mapei Group’s main productionsand distribution centres enforcethe Environmental Management SystemIn accordance with the ISO 14001 standard

EMAS is the EU environmentalmanagement systemin accordance tothe CE 761/01 regulation

In the year 2000 the Robbiano di Mediglia plant obtained the certifi cation of its occupational health and safety management system in accordane with the OHSAS 18001 standard, as well as the certifi cate of excellence that attests to its compliance with the requirements of the ISO 9001, ISO 14001, OHSAS 18001 standards and of CE 761/01 (EMAS) Regulation

Mapei Vietnam (1 plant)No. 162° Nguyen Chi Thanh streetHai Chau District - Da Nang - VietnamTel. +84 511 356 5001 / 02 / 03 / 04

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Group HeadquartersMapei / DAM ItalyVia Cafi ero 2220158 Milano - ItalyTel. +39 02 376 73 760

Internet:www.mapei.it/damE-mail:[email protected]

Mapei Italy (2 plants)Strada Provinciale 15920060 Robbiano di Mediglia (MI) - Italy and 84100 Salerno - Italy Tel. +39 02 376 73 760

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