Potassium fluoride is an important inorganic fluorine chemical products, widely used in medicine, anti-corrosion and glass carving, etc., especially in the synthesis of fluorine-containing organic products has an important role. With the shortcomings of traditional fluorochemical fluorite, the use of wet phosphoric acid to produce fluorine resources in the production of potassium fluoride is of great significance.

The fluoride resources in the liquid phase of the wet phosphoric acid are used to defluoride and prepare potassium fluoride. In this paper, the preparation process of defluorination and potassium fluoride was studied, and the related mechanism was studied and analyzed. The desulfurization process of wet-process phosphoric acid with potassium sulfate and potassium chloride as fluoride was studied. The optimum desulfurization conditions of potassium sulfate were as follows: the dosage of potassium sulfate was 1.2 times of the theoretical amount, the reaction time was 1h, the reaction temperature was 30 ℃. The best defluorination process of potassium chloride is: the amount of potassium chloride is the theoretical dosage of 1 times, the reaction time is 1h, the reaction temperature is 30 ℃. The reaction was carried out under stirring and the stirring speed was 30 rpm. At the same time, the experiment also studied the fluorination process of fluorosilicic acid, the best technological conditions are as follows: the reaction temperature of 30 ℃, potassium sulfate and potassium chloride dosage is the theoretical amount of 1 times the reaction time of 1h, Acid yield of about 92%. In the experiment, the defluorination process was studied. The flocculant was silica, and it was found that the reactive silica had good defluorination effect. The reaction of the hydrofluoric acid in the silica and the wet phosphoric acid was continuous reaction , The production of silicon tetrafluoride into fluorosilicic acid; experimental also potassium sulfate recovery of wet phosphoric acid and fluorosilicic acid in the process of fluorosilicic acid thermodynamic analysis of the reaction product of potassium fluorosilicate yield mainly by chemical reaction balance and precipitation of potassium fluorosilicate precipitation balance, but because the reaction equilibrium is very large, it can be considered a complete reaction, the yield of potassium fluorosilicate is mainly controlled by the precipitation of potassium fluorosilicate. The optimum conditions were as follows: the amount of potassium hydroxide was 1.07 times of the theoretical dosage, the reaction time was 1h, the reaction temperature was 80 ℃, and the reaction conditions were as follows: the reaction temperature was 80 ℃, potassium concentration of 30% to 40%.