Manufacturing Of Cement

MANUFACTURING OF CEMENT

Raw materials used

ü Calcareous

ü Argillaceous

Calcareous materials used are

ü Cement rock

ü Lime stone

ü Marl

ü Chalk

ü      Marine shell Argillaceous materials used are

ü Clay

ü shale

ü slate

ü blast furnace slag

Process manufacturing cement

ü Dry process

ü Wet process

1.Dry process

Lime stone and clay are ground to fine powder separately and are mixed together Water is added to make a thick paste which contains 14% of moisture. The paste format are dried and off charged into a rotary kiln. The product obtained often calcinations in rotary kiln. The linker I obtained as a result of incipient fusion and sintering at a temp about 1400?c to 1500? c. The linker is cooled to preserve the meta stable compounds and there solid solutions Dispersion of one solid with another solid which made the clinker again heated Clinker is again cooled and grounded in tube mills where 2-3% gypsum is added. The purpose of adding gypsum is to coat the cement particle by interfering the process of hydration of cement particles.

2 Wet process

The operations are

·       Mixing

·       Burning

·       Grinding

Process

The crushed raw materials are fed in to a ball mill and a little water is added. The steel balls in the ball mill pulverized the raw material which form a slurry with water. The slurry is passed through storage tanks where the proportioning of compound is adjusted to ensure desired chemical composition. The corrected slurry having moisture about 40%,is then fed into rotary kiln where it loses moisture and form on to lumps. These are finally burned at 1500? to 1600 ?c.

It becomes clinker at this stage, the clinker is cooled and then grounded in tube mills While grinding the clinker 3% gypsum I added this is stored in silos and packed.