PROCESS FOR THE PRODUCTION OF ALUMINIUM FLUORIDE TRIHYDRATE

摘要

In the process for the production of aluminium fluoride trihydrate by reaction of aluminium hydroxide with hexafluorosilicic acid, 2 to 3% aluminum ( as A 1 in relation to SiO2 dry) remain behind in the dilicic acid occurring as by-product, and consequently reduce the yield of aluminium fluoride trihydrate The yield of the aluminium fluoride trihydrate production process as regards the expensive aluminium component can be increased in that the silicic acid , after a brief washing with mother liquor from the aluminium fluoride trihydrate crystallization, is treated with agitation with the whole of the hexafluorosilicic acid, heated to 60 to 100C, used for the subsequent reaction, and filtered off, in that mother liquor washing filterate is united with the reaction solution metastably containing the aluminium fluoride, wherefrom the aluminium fluoride trihydrate is crystallized out, and the hexafluorosilicic acid filtrate, preferably heated to 80 to 95C, is brought together with the filter cake washing water to rapid reaction with the aluminum hydroxide