Method for preparing potassium fluoride with white carbon black as co-product by using fluorosilicic acid as raw material

Abstract

The invention relates to a method for preparing potassium fluoride with white carbon black as co-product by using fluorosilicic acid as a raw material. The method comprises the following steps: S1 dissolving potassium chloride and filtering to obtain potassium chloride solution; S2, injecting the potassium chloride solution obtained by S1 into the fluorosilicic acid solution for reaction, and after the reaction is completed, stirring, filtering and washing to obtain the potassium fluorosilicate filter cake; S3, adding water in proportion to the potassium fluosilicate filter cake obtained in the step S2 and stirring into a paste to obtain potassium fluosilicate slurry, and then injecting potassium hydroxide solution into the slurry to carry out reaction; S4, after the reaction is completed,filtering the mixed slurry obtained in the step S3 to obtain a silica filter cake and a filtrate containing potassium fluoride. The invention uses fluorosilicic acid as a raw material to prepare potassium fluoride with white carbon black as co-product, and the by-product potassium chloride and by-product silicofluoric acid from hydrofluoric acid industry are used as main raw materials to preparehigh purity potassium fluoride with high added value white carbon black as co-product. Compared with the raw materials in the neutralization method in which potassium hydroxide and hydrofluoric acid are reacted are used for the longest time at present, the production cost of the method is low.

Description

technical field [0001] The invention belongs to the technical field of fluorine chemical industry, and in particular relates to a method for preparing potassium fluoride and co-producing white carbon black by using fluosilicic acid as a raw material. Background technique [0002] Potassium fluoride is white monoclinic crystal or crystalline powder, salty, easy to absorb moisture, soluble in water, insoluble in ethanol, its aqueous solution is alkaline, can corrode glass and porcelain, relative density is 2.454, melting point is 858°C; available Used in glass engraving, food preservation, electroplating, welding flux, insecticide, catalyst, absorbent (absorbing HF and moisture), used as analytical reagent, complex forming agent, and raw material for preparing potassium bifluoride; [0003] White carbon black is the general term for white powdery X-ray amorphous silicic acid and silicate products, mainly refers to precipitated silica, fumed silica and ultrafine silica gel, and...

AI Technical Summary

Problems solved by technology

The traditional method of preparing white carbon black is to use sodium silicate, silicon tetrachloride, and ethyl orthosilicate as the silicon source. Except for sodium silicate, other costs are very high

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