METHOD FOR PROCESSING NON-SELECTIVE GALVANIC AND PHOSPHATIC MUDS

摘要

Zinc redn. is used to recover Cu, Sb, Pb, and As from waste HCl and HCl/HNO3 solns. Fe(-), Cr(-), and Al hydroxides are pptd. with NH4. Fe may be pptd. as phosphate. The ppte. is dissolved in an acid, iron hydroxide and phosphate are pptd. with alkaline hydrogen peroxide, Al and Cr remain in soln. Al is crystallised from the alkaline soln., Cr is recovered as dischromate by evapn. with an acid. - After the sepn. of the above ions, NaOH is used to ppte. hydroxides of Ni, Mn, Co and Cd. Zn complex remains in soln. The filtered hydroxides are dissolved in acetic acid, KNO2 pptes. the Co, H2S pptes. Cd, alkaline pptes. Mn and Fe hydroxides. Mn and Fe are sepd. by H2O2, Ni is pptd. as amino complex.