Cryolite, also known as sodium hexafluoroaluminate, is a mineral that is slightly soluble in water. Molten cryolite can dissolve alumina. It can be used as a flux in the electrolytic aluminum industry, a shading agent for manufacturing milky glass and enamel, and also as a wear-resistant additive for grinding products. It can effectively improve the wear resistance, cutting and cutting of high grinding wheel, and prolong the service life and storage time of grinding wheel.

The ignition loss is an important test index of cryolite, which is the proportion of two percent of the ignition loss of cryolite material at 550 ℃ for 0.5h. The burning of cryolite was a new index when the national standard was formulated in 1999, but there was no such index in the national standard in 1984. With the progress of society and the development of aluminum electrolysis industry, the automation level and environmental protection of industrial production have been paid attention to and urgently need to be improved. As the raw material of aluminum electrolysis - cryolite, its performance also needs to be improved.

Cryolite calcination directly affects its application effect in aluminum electrolysis production. High calcination alkali will cause cryolite hydrolysis, flying, low material utilization rate, aggravating environmental pollution and other problems. The lower the calcination, the better the application effect. Therefore, reducing burning loss is the primary problem to improve the quality of cryolite products and produce high-quality cryolite.