Cement Manufacturing Process

MADE BY:-ABHINAV KP

• Cement sector notably plays a critical role in the economic growth of the country•  Cement is vital to the construction sector

and all infrastructural projects.•  Occupies an important place in the

Indian economy because of • Construction• Transportation• Coal• Power

 

INTRODUCTION

• Concrete is the second most consumed material after water, with nearly three tones used annually for each person on the planet.• One of the basic elements for setting up

strong and healthy infrastructure cement plays a crucial role in the economic development of any country• The Indian cement industry is the second

largest producer of cement in the world after China • Cement industry in India comprises 183

large cement plants and over 365 mini cement plants

• Produced strictly as per the Bureau of Indian Standards (BIS) specifications and their quality is comparable with the best in the world.• Indian cement majors—ACC Ltd, Gujarat Ambuja Cements ,Ultratech

•  Industry is split into five geographical segments named as • North • South• East• West • Central

GEOGRAPHIC DISTRIBUTION

ComPosition of Cement

Portland Cement

. A hydraulic cement made by finely powderising the clinker produced by calcining to incipient fusion a mixture of argillaceous and calcareous materials.

.Portland cement is a powder that is the active ingredient in concrete.

Concrete

It is prepared by:-

. Shovel powder…………Portland Cement

. Shovels sand…………Mineral Aggregate

. Shovels Rock………. Mineral Aggregate

. Add water & mix.

. It is ready to mend .

• Mixture of ingredients into a paste &triggers a chemical reaction – hydration.

• Reaction forms a gel which coats & fills

spaces between the stone/sand;• Hardens into a solid mass thatgets stronger & stronger.

• The world’s most widely used building

material.• Global production is 5 billion cubic yards

per year (using approximately 1.25 billion

tons of cement).

Concrete owes its strength anddurability to one essential ingredient -Portland Cement.

Portland Cement

• Limestone + Shale/Clay + Heat = Clinker +

CKD + Exit Gas.• Material Temperatures Exceed 2700

degrees F• Pulverized Clinker + Gypsum = PortlandCement.• Cement is powder so fine that one poundcontains 150 billion grains.

– Calcium (Ca)– Silicon (Si)– Aluminum (Al)– Iron (Fe)• Typical Raw Materials:– Limestone (CaCO3)– Sand (SiO2)– Shale, Clay (SiO2, Al2O3, Fe2O3)– Iron Ore/Mill Scale (Fe2O3)

Basic Chemical Components of Portland Cement:

. Calcareous Component . Argillaceous Component

(providing Lime - CaO) (SiO2, Al2O3, and Fe2O3)

– limestone -clay– marly limestone -shale– chalk -calcareous

marl– coral limestone -marl– marble -marly clay– lime-sand -tuff, ash– shell deposits - phyllite ,slate

– lime sludge -glass

• Clinker Chemistry– Tricalcium silicate (3CaO.SiO2), (50-

70%)– Dicalcium silicate (2CaO.SiO2), (15-30%)– Tricalcium aluminate (3CaO.Al2O3), (5-

10%)– Tetracalcium aluminoferrite(4CaO.Al2O3.Fe2O3), (5-15%)

SiO2

CaO

CaO

CaO

CaO

CaO

CaO

Al2O3

History of Portland Cement

• First cements produced by early Greeks andRomans from volcanic ash mixed with slaked lime.• This art was lost during the Middle Ages.• Portland cement developed in England bybricklayer Joseph Aspdin in early 1800’s.• Called “Portland” because concrete made with itresembled natural stone from the Isle of Portland.

• First rotary kiln designed to produce Portlandcement patented in 1885 by Frederick Ransome.• First economical U.S. kilns developed by AtlasCement Company in 1895.• Thomas A. Edison first developed long kilns

(150feet compared to 60 to 80 feet).

Types of Cement Processes

• Wet Process.• Dry Process - 74% of cement produced.

• Preheater/Precalciner Process.

Evolution of the cement Process

• Wet process easiest to control chemistry & better

for moist raw materials.• Wet process high fuel requirements - fuel

neededto evaporate 30+% slurry water.• Dry process kilns less fuel requirements• Preheater/Precalciner further enhance fuelefficiency & allow for high production rates.

Cement Kilns

• High temperature• Long residence time• Natural alkalineenvironment• CKD is only by-product of the process.• Thermal stability

Kiln Process Control

• Critical Parameters: Fuel, Feed,Kiln Speed, Gas Flow• Kiln Temperatures - Burning

Zone• Kiln Stability• Chemistry• Instrumentation

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