What is the relationship between lime calcination speed and temperature
In the process of lime calcination, there is a significant correlation between calcination speed and temperature, which profoundly affects the efficiency and quality of lime production.
The decomposition rate of limestone (CaCO3) is greatly affected by temperature. Taking specific data as an example, when the calcination temperature is 900 ℃, the decomposition rate of limestone is slow, only able to burn through 3mm per hour; when the temperature rises to 1000 ℃, the decomposition rate significantly accelerates, and can burn through 6.6mm per hour, almost doubling; The temperature was further increased to 1100 ℃, and the decomposition rate was even more astonishing, reaching 14mm per hour, nearly five times higher than at 900 ℃. This clearly indicates that an increase in temperature will significantly accelerate the decomposition rate of limestone.
The selection of calcination temperature is crucial in actual lime production. Usually, the calcination temperature of a lime kiln is set at around 1050 ℃, and the decomposition rate of limestone is about 10mm per hour. However, in practical operation, taking spherical limestone with a diameter of 150mm as an example, the theoretical calcination time is 7.5 hours, but in reality it needs to exceed 24 hours. This is because the depth of heat transfer inside limestone increases, causing an increase in the resistance to carbon dioxide escape and slowing down the decomposition rate. Therefore, considering various factors comprehensively and controlling the calcination temperature and time reasonably can achieve efficient and high-quality lime production.
