Production process for preparing aluminium fluoride by using ammonium bicarbonate

Abstract

The invention relates to a production process for preparing aluminium fluoride by using ammonium bicarbonate, which solves the problem that the prior wet-method aluminium fluoride production process adopts more expensive aluminium hydroxide as a raw material, reduces production cost and is easy to carry out industrial production. The process is characterized in that fluosilicic acid reacts with ammonium bicarbonate to generate ammonium fluoride solution and silicon dioxide deposition; then, the filtered and separated ammonium fluoride solution reacts with aluminum chloride hexahydrate to prepare soluble Beta-AlF3.3H2O and ammonium chloride solution; soluble Alpha-AlF3.3H2O is converted into insoluble Beta-AlF3.3H2O through crystallization; and the finished product of aluminium fluoride isobtained through separation, washing, drying and calcination. The process is the most economical process for producing aluminium fluoride from a by product fluosilicic acid of enterprises for producing phosphoric acid and calcium superphosphate by a wet-method.

Description

1. Technical field [0001] The invention belongs to a production method of aluminum fluoride, in particular to an economical production process for producing aluminum fluoride by using silicon fluoride and ammonium bicarbonate. 2. Background technology [0002] Fluosilicic acid is a by-product of wet-process phosphoric acid and superphosphate production, which can be used to produce aluminum fluoride, sodium fluoride, sodium fluorosilicate, high-purity silicon dioxide, etc. Fluorosilicic acid is often used to produce aluminum fluoride in large-scale phosphate and compound fertilizer production plants, such as Guizhou Wengfu Mineral Fertilizer Base and Jiangxi Guixi Fertilizer Factory. The former imported technology and devices from the United States, and the latter from France. The aluminum fluoride production line of Jiangxi Guixi Chemical Fertilizer Plant has been shut down since it was put into trial production in 1991 due to the defects of the device itself and the influ...

AI Technical Summary

Problems solved by technology

The imported aluminum fluoride production lines above all use fluorosilicic acid and aluminum hydroxide as raw materials. Although the technology is advanced, the fly in the ointment is: ①The process conditions are demanding, and defective products will be produced if you don’t pay attention; ②The investment is large, such as Weng Funian An investment of 170 million yuan was invested in an aluminum fluoride plant producing 14,000 tons; 2 Discharge with slag; ④ requires ω(H 2 SiF 6 ) greater than 18%, low concentration of fluosilicic acid is not applicable