The principle and attention of calcined dolomite

When the dolomite rotary kiln is calcining dolomite, Mg-Al is fused, and the internal calcination process is actually an endothermic decomposition process. The thermal decomposition of dolomite is carried out in two stages: first, MgCO3 is decomposed to generate MgO; then CaCO3 is decomposed to generate CaO . The decomposition temperature of Mg2CO3 needs to be 720℃～800℃, and the decomposition temperature of CaCO3 needs to be 900℃～930℃. In actual production, the calcination temperature is slightly different due to the difference in the characteristics of the ore and the particle size of the calcined ore. Generally, the calcination temperature is set at 1100℃～1250℃, which can be determined through experiments. If the calcination temperature is too low, the decomposition will be incomplete, resulting in the phenomenon of "under-burning"; when the temperature is too high, the MgO grains will grow up and gradually lose activity, resulting in the phenomenon of "over-burning".

Fused magnesia-aluminum spinel

1. The good preheating of dolomite in the dolomite rotary kiln is a necessary condition to ensure the quality of calcination and save energy and reduce consumption. During the calcination process, the ore preheating should be strengthened as much as possible, and the kiln speed should be reasonably controlled. Ensure that the thickness of the material layer in the kiln is uniform.

2. When the rotary kiln is used as the calcining equipment, the particle size of the ore should be reasonably determined, and the particle size should be kept as uniform as possible. Because it affects the calcined white quality and activity of dolomite rotary kiln calcined.

3. In the rotary kiln, in order to ensure the emission rate of carbon dioxide gas, the kiln tail needs to maintain a certain negative pressure.