A method for producing anhydrous hydrogen fluoride from ammonium fluoride acidolysis mixed liquor

Abstract

The invention relates a fluorine-containing compound, in particular to a method for producing anhydrous hydrogen fluoride from an acid hydrolysis mixed solution of ammonium fluoride. The method comprises the following steps: 1) heating concentrated sulfuric acid to 170-220 DEG C, and keeping circulation; 2) spraying the acid hydrolysis mixed solution of ammonium fluoride to the surface of the circulating concentrated sulfuric acid, collecting gas, and performing cooling to obtain a hydrogen fluoride crude product; and 3) performing rectification and degassing on the hydrogen fluoride crude product to obtain an anhydrous hydrogen fluoride product. By use of the method provided by the invention, the anhydrous hydrogen fluoride product of which the content is more than 99.9% can be obtained, and the recovery rate of hydrogen fluoride is more than 92%. The method provided by the invention has the characteristics of simple process, low energy consumption, and safe and reliable operation, solves the problem of corrosion resistance of equipment, and improves the utilization rate of the equipment.

Description

technical field [0001] The invention relates to fluorine-containing compounds, in particular to a method for producing anhydrous hydrogen fluoride from ammonium fluoride acidolysis mixed liquor. Background technique [0002] In recent years, with the advancement of technology and the growth of demand, the application of fluorine products has penetrated into new industries such as construction, electronics, energy, environmental protection, information, and biomedicine. Fluorine resins, fluorine rubber, fluorine coatings, fluorine-containing fine chemicals, The demand for inorganic fluoride and other products is growing rapidly. However, with the rapid development of China's fluorine chemical industry, fluorite resources are becoming more and more depleted. Recycling and utilizing the rich fluorine resources in phosphate rock is not only beneficial to control fluorine pollution, but also helps to reduce the pressure on fluorite resources. . [0003] The traditional method of...

AI Technical Summary

Problems solved by technology

[0003] The traditional method of producing anhydrous hydrogen fluoride from fluosilicic acid is to react solid ammonium fluosilicate with 92%-99% concentrated sulfuric acid to produce SiF 4 Mixed gas with HF; the amount of sulfuric acid added is H 2 SO 4 Calculated as 100%-150% of the theoretical amount; analyze and volatilize SiF under vacuum conditions 4 and HF, the vacuum degree is controlled at 55kPa-85kPa, and the temperature is controlled at 120°C-140°C; 4 and HF, the temperature is controlled at 140°C-175°C; the mixed gas is washed, purified, and condensed to obtain anhydrous hydrogen fluoride, SiF 4 For the preparation of ammonium fluorosilicate, such as patent number 201210565361.1, "A method for preparing anhydrous hydrogen fluoride from fluorine-containing waste liquid or fluorosilicic acid of a phosphate fertilizer enterprise", which discloses the use of fluorine-containing waste gas absorption liquid or water in fluorosilicic acid Excluded by concentrated ammonium fluorosilicate, and then use concentrated sulfuric acid to acidify the solid ammonium fluorosilicate stage to produce a mixed gas of hydrogen fluoride and silicon tetrafluoride with a very low water content; but in the above scheme, the yield of hydrogen fluoride is not as good as satisfactory

[0004] At present, although there are many production methods of anhydrous hydrogen fluoride, most of them have the problems of low yield of hydrogen fluoride and serious corrosion of production equipment