METHOD FOR PRODUCTION OF ZINC NITRATE-PHOSPHATE CONCENTRATE Russian patent published in 1998 - IPC

FIELD: phosphating of carbon steel before anode and cathode electrodeposition in automobile industry, machine building and instrument making; phosphating of carbon steel and low alloyed steel without their preliminary mechanical cleansing. SUBSTANCE: aqueous solutions of zinc nitrate and nitric acid extract of apatite are added into aqueous solution of zinc monophosphate, ratio of zinc and P₂O₅= in zinc monophosphate being (1.0-1.25): (3.75-5.0), respectively. Ratio of Zn²⁺ and NO₃ in aqueous solution of zinc nitrate is (1.0-1.79):(3.07-3.6), respectively. Ratio of P₂O₅ and NO-3

in nitric acid extract of apatite concentrate is (1.0-1.15):(3.0-4.62), respectively. Temperature of working mixture is 40-50 C. Ratio of supplying aqueous solution of zinc nitrate and aqueous solution of nitric acid extract of apatite concentrate is 12.7-14.2 kg/cm³•min and 12.5-14.2 kg/cm³•min, respectively. EFFECT: improved efficiency of the method. 3 cl