METHOD OF AMMONIUM FLUORIDE SOLUTION PREPARING Russian patent published in 1995 - IPC

FIELD: production of phosphorus-containing fertilizers. SUBSTANCE: fluosilicic acid and/or ammonium silicofluoride is treated with ammonium carbonate and then ammonium solution is added to the reaction mass and silicon dioxide is separated from the end solution by known procedures. Ammonium carbonate is taken at quantity 1.6-2.2 g-mole and 1 g-mole fluosilicic acid or 0.6-1.2 g-mole per 1 g-mole ammonium silicofluoride. Use of ammonium carbonate ensures to decrease heat effect of process that excludes heat removal and heat-exchange surface cleansing. Degree of raw hydrolysis is 98-98.5% EFFECT: improved method of product producing. 3 cl, 2 tbl