99.2% Potassium Cryolite For Aluminum Magnesium Cast Boron Containing Alloys Potassium Cryolite is produced by the reaction of anhydrous hydrofluoric acid and aluminum hydroxide to produce fluoroaluminate, and then reacting with potassium hydroxide at high temperature, filtering, drying, melting and crushing. It can also be prepared by the reaction of aluminum fluoride, ammonium fluoride and potassium chloride. Physical properties: White or light gray powder, slightly soluble