Method for aminolysis of fluorosilicone compounds and separation of fluorine and silicon

Abstract

The invention discloses a separating method of aminolysis and hydrofluosilicic element of silicofluoride, which comprises the following steps: 1. adding solid ammonium fluosilicate or silicon tetrafluoride gas in the saturated ammonium fluoride circulating reacting liquid; putting raw material amino to proceed aminolysis reaction; 2. reducing slurry temperature; screening the reacted slurry; 3. filtering the screened silica suspension and ammonium fluoride crystal slurry to obtain saturated ammonium fluoride solution, silica solid and ammonium fluoride crystal; returning to former procedures as the circulating reacting liquid; washing the ammonium fluoride crystal; drying through normal drying method to obtain high-purity product. The invention can improves technological and economical index, which is fit for wet-producing phosphoric acid, phosphate fertilizer and other phosphor businesses.

Description

technical field [0001] The invention relates to inorganic fluorosilicon compounds such as silicon tetrafluoride, fluorosilicic acid, and fluorosilicate produced during the processing of wet-process phosphoric acid and phosphate fertilizer, in particular to the ammonolysis of fluorosilicon compounds and the separation method of fluorosilicon elements. Background technique [0002] It is well known that inorganic fluorosilicon compounds such as silicon tetrafluoride, fluorosilicic acid and fluorosilicate will be produced during the processing of wet-process phosphoric acid and phosphate fertilizer. If these by-products are not recycled, they will not only pollute the environment, but also cause waste of resources. The inorganic fluorosilicon compound is converted into ammonium fluoride and silicon dioxide by reacting with ammonia, ammonium hydroxide or ammonium carbonate, and then the ammonium fluoride and silicon dioxide are separated by filtration, thereby realizing the separ...

AI Technical Summary

Problems solved by technology

The ammonolysis and fluorine-silicon element separation methods of these technologies have the following defects: ①NH 4 F conversion rate is low: depending on the NH in the solution 4 Depending on the concentration of F and the reaction temperature, the conversion rate is only 70% to 95%; ②The ammonium fluoride solution contains a large amount of unprecipitated silica, which exists in the form of ammonium fluorosilicate, and contains NH 4 SiO in F20%~45% ammonium fluoride solution 2 The content is 0.27% to 1.9%, which will seriously deteriorate the technical and economic indicators of subsequent product production; ③ low concentration of ammonium fluoride: the mass fraction of ammonium fluoride solution is only 20% to 45%, which reduces the unit of subsequent product production equipment Volume production capacity; for processes that require evaporation and concentration, it also increases the energy consumption of product production