Method for producing hydrofluoric acid, waterless magnesium sulfate and sodium fluoride

Abstract

The process of producing hydrofluoric acid, anhydrous magnesium sulfate and sodium fluoride with sodium fluorosilicate and magnesia as material includes the following steps: 1. decomposing sodium fluorosilicate to produce sodium fluoride product and silicon tetrafluoride gas; 2. absorbing the gas with water, filtering to prepare fluorosilicic acid solution for preparing magnesium tetrafluoride, washing silica and drying to obtain carbon white; 3. reacting fluorosilicic acid solution and magnesia, filtering to obtain magnesium fluorosilicate solution, and concentrating to obtain crystal magnesium fluorosilicate hexahydrate; 4. decomposing magnesium fluorosilicate hexahydrate to produce magnesium fluoride solid, silicon tetrafluoride gas and water vapor; 5. absorbing the gas with water and hydrolyzing, filtering to obtain fluorosilicic acid solution returned to the step 3, washing silica and drying to obtain carbon white; and 6. reacting magnesium fluoride and sulfuric acid, condensing and rectifying to obtain hydrofluoric acid, and obtaining anhydrous magnesium sulfate.

Description

technical field [0001] The invention relates to a method for producing hydrofluoric acid, anhydrous magnesium sulfate and sodium fluoride, in particular to a method for producing hydrofluoric acid, anhydrous magnesium sulfate and sodium fluoride using sodium fluorosilicate and magnesium oxide as raw materials . Background technique [0002] Hydrofluoric acid can be used to produce fluorine refrigerants, fluorine-containing resins, organic synthesis (polymerization, condensation, alkylation) promoted fusion fluorine resins, flame retardants, dye synthesis, and the manufacture of organic or inorganic fluorides, such as fluorocarbons Compounds, aluminum fluoride, uranium hexanitride, cryolite, etc.; can also be used for etching glass, electroplating, reagents, fermentation, pottery treatment, catalysts in the petroleum industry, and the manufacture of frosted bulbs, and desanding of metal castings , the removal of graphite ash, the cleaning of metals (pickling copper, brass, s...

AI Technical Summary

Problems solved by technology

The traditional production process of sodium fluoride uses sodium fluorosilicate and soda ash as raw materials, reacts sodium fluorosilicate and soda ash in the water phase to generate a mixture slurry of sodium fluoride and silicon dioxide, and separates the two according to gravity sedimentation , get sodium fluoride product, use soda ash as raw material cost is higher