Patent ID: 11891344

Abstract:
The present disclosure discloses a method for graded utilization of fluorine and silicon resources in a phosphate ore. While the phosphate ore reacts with sulfuric acid, a fluorine-containing and silicon-containing tail gas is produced. SiO2 and H2SiF6 solution with a high concentration are obtained by concentrating and filtering a solution containing HF and H2SiF6 formed after tail gas is absorbed by water. Crude SiF4 and a solution containing HF and H2SO4 are obtained by extracting, adsorbing, and dehydrating the H2SiF6 solution. SiF4 with a 5N purity is obtained after the crude SiF4 is adsorbed and distilled, at the same time, an impurity-enriched SiF4 is returned to operations of concentration and filtration to react with the solution containing HF and H2SiF6 to generate the H2SiF6 and SiO2. High-purity HF and waste sulfuric acid are obtained after the H2SO4 solution containing HF is separated by steam stripping and distillation.