Cement making is a simple process in which carefully measured quantities of pozzolana, shale, iron ore and occasionally sand are blended together, ground to a fine powder and fused at a very high temperature in a rotary kiln. The fused material or 'clinker' is cooled and then ground with a small amount of gypsum in a ball mill to produce the finished cement powder.
Pozzolana is the primary raw material in cement with a high level of calcium carbonate. Chalk or coral can also be used. pozzolana is used which comes from Boral's pozzolana quarry at Marulan. pozzolana is a high grade stone won by blasting, then crushed before being transported by rail to the cement works. Shale is quarried on the cement works site The small quantity of iron ore required to make cement is obtained from outside resources. Sand is supplied locally when required for fine correction of the mix.
Pozzolana Cement Production Line As Following
- The dry ground meal is stored in a large blending silo.
- From the silo it is conveyed by elevator to the top of the pre-heater tower with four cyclone stages.
- The raw meal falls by gravity through each interconnected cyclone during which the hot gases from the kiln pass through the cyclones and heat the raw meal to approx 1000ºC
- From the bottom cyclone the hot meal enters the rotating kiln and travels toward the fusion zone, when it is heated to 1450ºC.
- As the hot clinker leaves the kiln it passes through a grate cooler where it is cooled to 120ºC and is then conveyed to storage.
The origin of cement dates back to man's earliest beginnings when builders' sought a material to bind stones together to build shelter and later homes. In the early Egyptian era, cement material was produced by burning gypsum. It is believed the Romans also developed the first known hydraulic cement – cement capable of hardening under water. Created by mixing slaked lime with a volcanic rock or sand called 'Pozzolana', the cement was named after the place where it was first found - Possuoli near Mount Vesuvius and is commonly known as Pozzolanic cement.