Complex Processing of Wastes Generated in Chrysotile Asbestos Production

摘要

A new recycling technology has been studied in this work to produce magnesium chloride from wastes generated in chrysotile asbestos production. The steps include enrichment of raw material by sizing, leaching of magnesium with hydrochloric acid, purification of solution from impurities of iron and nonferrous metals, and the production of magnesium chloride solutions. Thermodynamic analysis shows the possibility of dissolution of magnesium compounds in the waste by hydrochloric acid. Magnesium chloride solution is subjected to hydrolytic purification from iron and nickel. Enrichment has been carried out with material particle size of 0.25mm and liquid to solid ratio of 4:1 and leaching with 25% concentrated hydrochloric acid has been accomplished with a stoichiometric flow rate. Hydrolytic treatment was carried out at a pH 7.5-8.0. pH adjustment was carried out by magnesium oxide. Extraction of 92% of magnesium from serpentinite was achieved.