The cement production process is a complex process with a long history which mainly consists of crushing, grinding, homogenization, and calcining operations of raw materials and preheating, calcining and cooling operations of clinker. In the cement manufacturing process, the most common method used is the traditional wet process, and the more advanced cement production method uses the dry process with preheater and precalciner. The current mainstream method for cement production is the dry process cement production with preheater and precalciner technology.
The dry process cement production with preheater and precalciner technology is a complex process, it is generally divided into two main steps. First, the limestone and other components of the raw material are crushed and ground in order to prepare from the raw material needed in the cement production process. Second, the raw materials are further processed and heated in the calcination furnace to form clinker. Lastly, during the process of cement grinding, the clinker and other ingredients in the raw material are finely ground to produce the cement powder or cement clinker.
The production of cement is an energy intensive process and requires a large amount of fuel to heat, grind and homogenize the raw materials and the clinker to the desired product. For the purpose, our research focuses on a lime-burning method, in which limestone and coke, among other materials, are burned together in a kiln. The burning process releases a large amount of heat, heat which is necessary to clinkerize the raw materials. Clinkerization requires heating the raw materials to around 1450°C, while retaining the same temperature level in the kiln.
When making cement using the lime burning method, a foundation of limestone is laid on the floor of the kiln. The kiln is then heated and the limestone melts, reacts with the raw materials, and forms its cement clinker. During the whole process, the temperature is carefully regulated and must remain at the proper temperature or else the clinker will fail to form.
The lime burning method offers a number of advantages. One of its major benefits is that the fuel or limestone does not have to be pulverized to a fine powder before entering the kiln. As a result, the process uses less energy, making it more cost-effective. Additionally, the lime burning method requires a much lower kiln temperature, which lowers energy costs even further. Furthermore, it produces cement with fewer impurities and with better quality than the wet process cement production method.
The lime burning method also has some drawbacks, such as the risk of burns due to the high temperatures involved in the process. Additionally, the generated cement is of a lower grade and contains more impurities. The uncontrolled reaction of limestone to other materials creates dust particles which can be very dangerous to workers if inhaled. Finally, it is a well-known fact that excess lime can result in the corrosion of components of cement plant equipment, thus increasing maintenance costs.
Although the lime burning method presents some drawbacks, its overall performance remains competitive. In comparison to the other cement production methods, the lime burning method uses fewer raw materials, produces better quality cement, requires lower energy input, and has lower emissions. It is clear that this production method has gained in popularity and continues to gain acceptance in the cement industry.
