What are the cement production processes? Six major steps in the cement process
Cement is the most widely used building material for a variety of buildings, indoor and outdoor decoration. What are the cement production processes? Xiaobian will introduce you to the six major steps of the cement process.
1. Broken, pre-homogenized. In the cement production process, most of the raw materials are broken, such as limestone, clay, iron ore and coal. As the raw material for producing the largest amount of cement, limestone has a large particle size and high hardness. The crushing of limestone is the most important step in material crushing. The pre-homogenization technology is to use the scientific stacking and reclaiming technology in the process of depositing and taking raw materials, so that the raw materials are initially homogenized, and the raw material storage yard has the ability to store and homogenize.
2. Raw material preparation. In the cement production process, each ton of Portland cement needs to be ground for 3 tons of materials, including various raw materials, fuels, clinker, mixture, and gypsum. The power consumed by the dry cement production line is about the entire plant. More than 60% of the power, of which raw material grinding accounted for more than 30%, coal mill accounted for about 3%, cement grinding accounted for about 40%.
3. Raw material is homogenized. In the process of new dry process cement production, the stable raw material composition is the premise of stable clinker burning heat processing, and the raw material homogenization system has the effect of stabilizing the raw material composition.
4. Preheat decomposition. Preheating and partial decomposition of the raw material by the preheater can replace the function of the rotary kiln, and the length of the kiln can be shortened. The heat exchange between the kiln and the kiln can be carried out in a stacked state, and moved to the preheater to be carried out in a suspended state. The raw material can be completely mixed with the hot gas discharged from the kiln, increasing the contact area of the gas material, the heat transfer speed is fast, and the heat exchange efficiency is high.
5. The cement clinker is fired. After the raw material is preheated and pre-decomposed in the cyclone preheater, it is required to enter the rotary kiln for clinker firing. The carbonate is further rapidly decomposed in the rotary kiln and produces a series of solid phase reactions that produce minerals in the cement clinker. When the temperature of the material rises, the minerals will appear as a liquid image, which will dissolve in the liquid image to produce clinker. After the clinker is fired, the temperature gradually decreases. Finally, the high temperature clinker discharged from the rotary kiln is cooled by the cement clinker cooler to the temperature that can be withstood by the downstream conveying, storage and cement grinding, and the sensible heat of the high temperature clinker is recovered, and the thermal efficiency and clinker quality of the system are improved.
6, cement grinding. The final process in the cement process is also the most power consuming. Its main function is to grind the cement clinker to a suitable particle size, produce corresponding particle gradation, increase the hydration area, accelerate the hydration speed, and meet the cement slurry coagulation and hardening requirements.