Some of the byproducts of cryolite are also produced by chemical processes. The preparation processes of the former type mainly include mixed grinding method and synthesis method. Potassium cryolite manufacturers can call them general processes, and the latter type of products are the by-products of manufacturing Al-Ti-B central alloy. Al-Ti-B central alloy is the grain refiner of aluminum alloy, which must be added in the manufacture of aluminum materials, so as to refine the grain and structure of the alloy and improve the function of materials.
The important disadvantages of preparing potassium cryolite by mixed grinding method are: the basic material is KF or kalf4 or K3ALF6, which is expensive and difficult to prepare; The products prepared by potassium cryolite manufacturers often contain free KF, which is easy to dissolve in water and absorb water, causing weldment erosion. Although the melt grinding method does not have these shortcomings, it has cumbersome operation, high energy consumption and needs high-temperature melting and grinding. Therefore, the mixing method has been developed, and some commercial preparation processes such as potassium metaaluminate method, potassium fluoride method, potassium aluminum hydroxide method, potassium carbonate method and potassium compound method have been formed with Al (OH) 3, HF, KCl, Koh, K2CO3 and KBr as materials. Corundum carbide
Cryolite can melt alumina well, and the melt can be electrolyzed below the melting point of pure cryolite, with good activity. Second, at the electrolysis temperature, the density of cryolite alumina melt is 10% lower than that of aluminum melt, so the electrolytic aluminum melt can be deposited on the cathode under the electrolyte, which can reduce the oxidation loss of aluminum and greatly simplify the layout of aluminum electrolytic cell; Third, cryolite has superior conductivity; Fourth, cryolite does not contain metal impurities whose potential is higher than that of aluminum, which can ensure the quality of aluminum products. At present, cryolite or aluminum electrolytic manufacturing is a very ideal flux.
