1. Method for producing precipitated aluminum silicate (P820) Precipitated aluminum silicate is made of aluminum sulfate and sodium silicate. After the reaction, the precipitated aluminum silicate slurry is formed, aged, filtered, dried and air pulverized. Finished product. The iron-free aluminum sulfate and sodium silicate are used as raw materials to prepare a solution of a certain concentration; the two liquid materials are respectively added to the reaction tank with stirring and pre-added with water and a certain additive at a certain flow rate, and steam is used. Indirect heating, keeping the reaction temperature constant, by adjusting the flow rate of the raw material liquid, the system is maintained at a certain pH value for reaction, and then aging, filtering, washing, drying, and jet milling to obtain a qualified precipitated aluminum silicate product. 2, microsphere aluminum silicate gel: First, sodium silicate and sulfuric acid react to form silicic acid, silicic acid is very unstable, and soon aggregated into particles into a sol, sol gel becomes a hydrogel. Na2O·mSiO2 + H2SO4 = Na2SO4 + mSiO2 + H2O where m is the modulus and is generally between 3,0 and 3,3. After the formation of the silicon hydrogel, an aluminum sulfate solution is added and then neutralized with ammonia to form an aluminum hydroxide gel: AL2(SO4)3+6NH4OH = 3(NH4)2SO4+2 AL(OH)4 Special Flat Washers,Stainless Washers,Thick Washers,Flat Spring Washer NINGBO YWC IMP. & EXP. CO.,LTD , https://www.nbywc-fastener.com