Abstract
The present review systematizes and summarizes the results of research on utilization processes of fluorosilicic acid solutions as large-tonnage toxic by-products of phosphate fertilizers, phosphoric acid and elemental phosphorus production. Considering the marked decline in the world's fluorspar reserves, fluorosilicic acid is emerging as the main alternative source of fluoride for the chemical industry. The main ways of H2SiF6 processing are highlighted with obtaining of commercially demanded products: hexafluoridosilicates of metals and ammonium, metal fluorides, anhydrous hydrogen fluoride, hydrochloric acid, amorphous silicon dioxide, aluminosilicates and titanosilicates catalysts, and enriched isotopes of silicon. Examples of H2SiF6 use as a main reagent for drinking water fluoridation municipal programs, in processes of surface modification and removal of trialkylsilyl protection in reactions of organic synthesis are also discussed. Known examples of H2SiF6 use as a raw material and reagent in industrial technologies and laboratory tests largely conform to principles of green chemistry.
Publisher
SHEI Ukrainian State University of Chemical Technology
Subject
Materials Chemistry,General Chemical Engineering,Environmental Chemistry,General Chemistry