Explanation

cryolite is mainly composed of sodium hexafluoroaluminate or sodium aluminum fluoride. It is a small white crystal, odorless, with a specific gravity of 3, a hardness of 2-3, and a melting point of 1009 ℃. It is easy to absorb water and moisture. cryolite is mainly used as flux for aluminum electrolysis, wear-resistant filler for rubber and grinding wheel, enamel opacifying agent, glass shading agent and metal flux, pesticide for crops, etc. The Hall Heroult process is a method of producing metal aluminum with cryolite based fluoride melt as solvent. So far, no other compound has been found that can replace cryolite. This is because cryolite not only can dissolve aluminum oxide, but also has some other indispensable properties. For example, it does not contain elements that are more conductive than aluminum, has good stability, does not decompose, volatilize, or deliquescence under general conditions, has a melting point higher than aluminum, has good conductivity, and saves electricity. It can be said that without cryolite, the world might not have such a large-scale aluminum industry, the price would not be so low, and the application would not be so widespread. The west coast of Greenland is the main source of cryolite, which was mined in 1987. At present, fluorite is mostly used to synthesize sodium hexafluoroaluminate for industrial use. Spain, Russia, and the United States also have output.

Classification