Cement is the glue that holds the concrete together, and is therefore critical for meeting society's needs of housing and basic infrastructure. This paper deals with a case study of a reputed cement raw material milling, some changes in the process has been suggested, which leads to reduction in labor cost and production cost.
A Case Study Of Cement Raw Material Milling
Being one of the basic elements for setting up strong and healthy infrastructure, cement plays a crucial role in economic development of any country. Having more than a hundred and fifty years history, it has been used extensively in construction of anything, from a small building to a mammoth multi purpose project. This paper deals with a case study of a reputed process industry, some changes in the process has been suggested, which leads to reduction in labor cost and production cost.
There are three types of processes to form cement - the wet, semi-dry and dry processes. In the wet/semi-dry process, raw material is produced by mixing limestone and water (called slurry) and blending it with soft clay. In the dry process technology, crushed limestone and raw materials are ground and mixed together without the addition of water.
The dry and semi-wet processes are more fuel-efficient. The wet process requires 0.28 tonnes of coal and 110 kWh of power to manufacture one tonne of cement, whereas the dry process requires only 0.18 tonnes of coal and 100 kWh of power.
The major operations carried out in the cement raw material milling are as follows:
- Crushing of limestone, coal, and other materials
- Storage arid blending of raw materials
- Preparation of raw mix
- Raw mix grinding and homogenisation
- Pyro processing of raw materials in the kiln
- Cooling and storage of clinker
- Grinding of clinker with gypsum to cement
- Storage and dispatch of cement
The manufacturing process of cement consists of mixing, drying and grinding of limestone, clay and silica into a composite mass. In this process will need some cement crusher machines, such as jaw crusher, impact crusher,VSI crusher and so on.The mixture is then heated and burnt in a pre-heater and kiln to be cooled in an air-cooling system to form clinker, which is the semi-finished form. This clinker is cooled by air and subsequently ground with gypsum to form cement.