The production of potassium fluoride from industrial by-product fluorosilicic acid causes the accumulation of phosphate and sulfate in the potassium fluoride product to affect the product quality, and the amount of alkali used in the process of alkaline hydrolysis of potassium hydroxide is not good control, slightly over the amount of silica will dissolve and thus affect the product quality of potassium fluoride. Focused on the use of industrial by-product fluorosilicic acid preparation of high purity potassium fluoride co-production of white carbon black technology to solve the problem of impurity accumulation, depth analysis of the experimental principle, experimental method, key point control, product quality and cost. The technology has the characteristics of low production cost, good product quality, reasonable process and small environmental pollution, which is in line with the national energy saving and emission reduction and the comprehensive utilization of resources industry policy.