Method for producing high-purity ammonium bifluoride

Abstract

The invention discloses a method for producing high-purity ammonium bifluoride, which comprises the following steps of: (1) under the stirring condition, introducing anhydrous hydrogen fluoride into saturated solution of ammonium fluoride until the pH value of the reaction liquid ranges from 1 to 4, and stopping introducing the anhydrous hydrogen fluoride, wherein the temperature is controlled between 25 and 50 DEG C in the reaction process; (2) cooling the reaction liquid to the temperature of between 5 and 20 DEG C, and keeping the temperature for 2 to 4 hours until crystals separate out; and (3) filtering, drying a filter cake to obtain the product of high-purity ammonium bifluoride, and recycling the filter liquor. The method for producing the high-purity ammonium bifluoride has the advantages of small equipment investment, simple process, easy operation, and low moisture content, high purity, high dissolving speed, convenient use, hard agglomeration, and long-term storage of the product ammonium bifluoride. The mother solution is circulated in a closed loop, and the whole technical process has no liquid waste discharge. The raw material ammonium fluoride is prepared by ammonolysis of a byproduct fluosilicic acid in the phosphate fertilizer industry, and the method has the advantages of easily obtained raw materials, low cost, and low production cost. The method provides a new fluoride source, and solves the problem of environmental pollution in the phosphate fertilizer industry.

Description

technical field [0001] The invention relates to a production method of ammonium bifluoride, in particular to a production method of high-purity ammonium bifluoride. Background technique [0002] Ammonium bifluoride can be used as a chemical reagent, glass etchant, disinfectant and antiseptic in fermentation industry, solvent for metal beryllium made of beryllium oxide, and surface treatment agent for silicon steel plates. It is also used in the manufacture of ceramics, magnesium alloys, boiler feed water systems and steam It can be used for cleaning and descaling of generation system, as well as acid treatment of sandstone in oil field, and also used as catalyst component of alkylation and isomerization, etc. [0003] The traditional production methods of ammonium bifluoride mainly include liquid phase method and gas phase method, both of which use hydrofluoric acid and ammonia as raw materials. The liquid-phase method is obtained by vaporizing liquid ammonia and passing it...

AI Technical Summary

Problems solved by technology

Among the above preparation methods, the liquid phase method has less investment and simple process, but the ammonium bifluoride produced has high water content, low purity, slow product dissolution rate, inconvenient use, easy caking, and cannot be stored for a long time

The gas phase method has the disadvantages of large equipment investment and high cost

The direct concentration and decomposition of ammonium fluoride solution to prepare ammonium bifluoride also has the disadvantages of high energy consumption and high cost.