The FLSmidth OK millThe high-effiency and reliable roller mill for cement

and slag grinding

FLSmidth – Slide 1

First FLSmidth vertical mill (1922)

FLSmidth – Slide 2

ATOX Raw Mill

FLSmidth – Slide 3

• Simple and space-saving layout

• Proven technology based on alicense (1993) from Onoda and

Kobe Steel, Japan

• High efficiency separator

• Equivalent or better cement quality

OK Mill layout

FLSmidth – Slide 4

• Equivalent or better cement qualitythan tube mill cement

• Energy saving. 25% to 45% in kWhcompared to Ball Tube Mills

• Very suitable for grinding blendedcement or slag

• Easily controllable particle sizedistribution

• Easy maintenance due toswing-in/out roller support system

FLSmidth OK mill

Separator

Grinding roller

Separator drive

Mill outlet

FLSmidth – Slide 5

Rocker arm

Gear box

Mill stand

Mill feed inlet

Grinding table

Hydraulic system

OK Mill - a Unique design developed specifically fo r cement and slag grinding ……

FLSmidth – Slide 6

OK Vertical mill grinding partsPressure distribution

FLSmidth – Slide 7

OK mill efficiency compared to ball mills

50

55

60

65

70

Spec. Energy Cons.,Tota

l, kW

h/t

Ball mill

FLSmidth – Slide 8

20

25

30

35

40

45

2500 2700 2900 3100 3300 3500 3700 3900 4100 4300 4500

Blaine, cm2/g

Spec. Energy Cons.,Tota

l, kW

h/t

OK mill

≈ 33 %

≈ 45 %

Raw material preparation

38%Cement grinding

44%

Cement storage / dispatch

1%

with OK mill

Importance of cement grinding on total plant power consumption

FLSmidth – Slide 9

Clinker production

17%

Raw material preparation

44%

Clinker production

19%

Cement grinding

36%

Cement storage / dispatch

1%

with ball mill

with OK mill

CO2 reduction substituting ball mill with OK mill

Example

40,000

50,000

60,000

CO2 reduction, t CO2 per year

Clinker production capacity: 1.5 mill t/yearCement type: Ordinary Portland CementEF = Emission Factor (tCO2/MWh)

EF = 1.0

EF = 0.75

FLSmidth – Slide 10

0

10,000

20,000

30,000

2500 3000 3500 4000 4500 5000

Blaine, cm2/g

CO2 reduction, t CO2 per year

EF = 0.5

Clinker replacement materials for blended cement

It is good for the environment:

• Saving of raw materials

• Energy saving

• Reduced CO2 emission

• Waste utilization (slag and fly ash)

FLSmidth – Slide 11

OK mill is very suitable for grinding of blended cement:

• It is more versatile than a ball mill. Separate drying facilities are not required. It is easy to change from one product type to another product with practically no transition periods between products.

• Besides pure slag it can grind any type blended of cement with additives such as limestone, pozzolana, fly ash and slag; even with high water content

50

60

70

80

90

100

OK mills - Composition of mill feed

FLSmidth – Slide 12

0

10

20

30

40

A+B C C D D D E F + G +H

I + J I + J

Plant

Clinker, % Gypsum, % Limestone, % Pozzolana, % Slag, % Fly ash, %

Entry Cement type Capacity, t/h Blaine kWh/t Guarant. Achieved Guarant. Achieved Garant. Achieve d

1 Slag cement 145 192 3670 3550 37.1 28.3 2 OPC 170 189 3000 2900 26.3 23.0 3 OPC 170 189 3000 3300 26.3 24.3

Slag cement 55 60 4000 4105 36.0 34.4 4

Slag 45 51 4000 3982 44.0 40.3 5 OPC 66 70 3800 3800 34.3 31.0 6 OPC 145 161 3000 3060 24.8 21.8 7 Blended 140 155 7% > 45 µµµµ 6.2% > 45 µµµµ 17.2 (Mill) 17.6 (Mill) 8 Blended 170 172 4400 4378 None 27.4

+ 9 % + 3 % - 14 %

OK mill performance

FLSmidth – Slide 13

8 Blended 170 172 4400 4378 None 27.4 9 OPC 118 144 3900 3900 - 25.7

10 Blended 120 130 3450 3900 26.8 22.8 11 Blended 150 154 3200 3650 22.9 18.3 12 Slag 84 91 4600 (a) 4210 (b) 32.5 (M+S) 31.1 (M+S) 13 OPC 150 150 3300 3350 19.7 18.0 14 OPC 152 155 3800 4024 36.7 29,4 15 OPC 154 166 3750 3743 n/a 29,4 16 Blended 120 123 3450 3700 26.8 23.5 17 OPC 180 186 3000 3050 29 21.5 18 OPC 175 194 3000 3050 n/a 22,6 19 OPC 180 182 3200 3300 33 25,4 20 OPC 180 189 3200 3230 33 26,0 21 Blended 120 138 3650 3702 27 20,0

(a): With gypsum (b): Without gypsum

150.0

200.0

250.0

3000

4000

5000

3800 - Guar.

Guar. - 168

Easy commissioning of millFirst 40 days of OK mill operation

FLSmidth – Slide 14

0.0

50.0

100.0

150.0

2/1 2/3 2/5 2/7 2/9 2/11 2/14 2/16 2/18 2/20 2/22 2/24 2/26 2/28 3/3 3/5 3/7

Date, 2006

Pro

duct

ion

0

1000

2000

3000

Bla

ine

OK mill – product quality

Plant Plant A Plant B Plant C

Cement type OPC Blended Blended

Mill BM OK BM-1 BM-2 OK-1 OK-2 BM OK

Fineness . PSD

Blaine(m2/kg) 375 377 399 436 399 376 437 385

Res. 45 µm (%) 5.3 1.3 5.4 5.6 7.4 4.5 2.4 3.2

PSD / d-50% (µm) 13.4 12.0 13.6 12.8 14.1 14.9 11.7 13.0

PSD / d’ (µm) 17.7 16.3 18.6 17.8 19.4 19.5 16.3 17.6

PSD / n-value 1.05 1.10 1.11 1.07 1.07 1.06 1.01 1.05

FLSmidth – Slide 15

PSD / n-value 1.05 1.10 1.11 1.07 1.07 1.06 1.01 1.05

Dehydr./Prehydr.

Gypsum (%) 0.1 2.0 1.2 0.9 1.9 3.2 4.0 3.5

Hemihydr. (%) 1.5 0.5 2.3 2.3 1.7 1.0 2.0 1.5

Prehydr. (%) 0.25 0.15 - - - - 0.29 0.20

Cement testing (EN / ISO)

Water to NC (%) 27.0 26.5 29.5 29.0 31.0 32.5 27.5 27.5

Initial set (h:min) 2:05 1:50 2:35 2:25 3:05 3:15 1:20 1:45

Final set (h:min) 2:50 2:40 3:20 3:10 4:00 4:20 2:30 2:30

Str.-1day (MPa) 19.0 18.8 13.8 12.1 10.6 10.2 15.5 14.8

Str.-2 days (MPa) 27.6 28.8 32.1 32.5

Str.-3 day (MPa) 29.8 28.4 26.9 28.8

Str.-7 day (MPa) 39.0 42.8 39.4 36.1 35.7 37.5 39.8 41.7

Str.-28 day (MPa) 60.5 60.3 50.0 47.9 49.2 50.3 50.5 52.0

Conclusion: Quality of cements produced in OK mills is very similar to those produced in ball mills with high efficiency separators

50

60

70

80

Num

ber

of m

ills

sold

Sale of ball mills and VRM for cement grinding ex. China

FLSmidth – Slide 16

0

10

20

30

40

Num

ber

of m

ills

sold

2003 2004 2005 2006 2007

BMVRM

OK mills sold – July 2008

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OK

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OK

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OK

OK

OK

OK

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OK

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OK

OK

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OK

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All together 92 FLSmidth OK mills sold world wide

OK OK

OK

OKOK

OK

OK

Summary of experiences with OK Mills commissioned by FLSmidth

• The production is above guaranteed

• The spec. energy consumption below guaranteed

• It grinds all kind of cements with additives

FLSmidth – Slide 18

• It grinds all kind of cements with additives

• The operational parameters can be adjusted to meet quality requirements

• It can be operated with two rollers only

• It is reliable in operation, easy to operate and easy to maintain

Thank you for your attention

FLSmidth – Slide 19