PROCESS FOR RECOVERY OF PRECIOUS METALS

摘要

A process for the recovery of metals (hereinafter PM) from solids includes dissolving the PM and base metals in acid. The PM are precipitated using substituted quaternary ammonium salts (hereinafter SQAS). The PM may be oxidized or reduced. The substituted quaternary ammonium salts are generally stated as H_0-3 R_4-1 NX where H = hydrogen, R = organic group, N = nitrogen and X = halide, tetramethylammonium chloride being employed in the Examples. Au-SQAS is separated by washing with solvent. Rh-SQAS is dissolved in acid, oxidized to precipitate salts and separated. SQAS is added to the filtrate, heated and cooled to precipitate Rh- SQAS which is separated. Rh-SQAS is purified before forming a final product. Other metals are separated by boiling the initial acidic solution of metals to precipitate metal salts, cooling and separating. The filtrate is oxidized. Pd-SQAS is dissolved and separated. A slurry is separated by dissolving and separating.