What is the melting point of cryolite?

What is the melting point of cryolite?

Cryolite is used as a solvent to dissolve alumina and then electrolyze. Cryolite plays a key role here. It solves the difficulty of high melting point of alumina (up to 2050°C), non-conductivity, and the melting point of cryolite that cannot be electrolyzed alone. After alumina is dissolved in cryolite, it can be electrolyzed at a temperature of 940℃～980℃. Cryolite has other magical functions. It is lighter than aluminum when it is in a molten state. The aluminum obtained by electrolysis sinks to the bottom of the tank, and cryolite floats on it, which plays an effect of preventing aluminum from being oxidized by air.

    Cryolite is used the most in the aluminum industry. The annual consumption in the world is about 700,000 tons. In 1999, the sales volume of cryolite in China was about 130,000 tons. The melting point of cryolite is used as a flux for electrolytic aluminum smelting, and cryolite must meet certain requirements in terms of sodium-aluminum molecular ratio, impurity content, and water content.

    First, the ratio of sodium to aluminum in cryolite should be as high as possible. The higher the molecular ratio, the higher the current efficiency of electrolytic aluminum smelting, the less fluorine is lost, the less environmental pollution is formed, and the polymer is more suitable than cryolite. Use of occupations other than aluminum industry

    In addition to dissolving alumina, it also has other indispensable properties. For example, it does not contain more positively charged elements than aluminum. It has good stability and decomposes under normal conditions. The melting point of cryolite is non-volatile and non-deliquescent, and its melting point is higher than that of aluminum. , Good conductivity, potassium cryolite saves electricity and so on. It can be said that if there is no cryolite, there may not be such a large-scale aluminum industry in the world, the price is not so low, and the application is not so widespread.

    Cryolite can be divided into high molecular ratio cryolite and low molecular ratio cryolite according to the molecular comparison of sodium and aluminum. And this is divided into sand cryolite, cryolite melting point granular cryolite and powder cryolite according to its physics class. Different shapes, effects and requirements are also different, we can choose suitable products according to our needs.