Recovery of Silver from the Nitrate Leaching Solution of a Spent Ag/α-Al₂O₃ Catalyst by Solvent Extraction and Reduction

Abstract

Nitric acid was employed to strip silver from loaded 5,8-diethyl-7-hydroxy-dodecan-6-oxime (LIX63) in the recovery of silver from a leaching solution of a spent Ag/α-Al 2 O 3 catalyst. The loaded LIX63 was obtained by contacting the real leaching solution with 0.5 mol/dm 3 LIX63 diluted in kerosene. In order to produce silver powder by reduction, the HNO 3 in the stripping solution was recovered by extraction with tri 2-ethylhexyl amine (TEHA) followed by stripping with distilled water. Silver powder was obtained by reduction with 0.1 mol/dm 3 L-ascorbic acid. A owsheet was proposed to recover Ag from the leaching solution of the spent Ag/α-Al 2 O 3 catalyst by solvent extraction and reduction with minimum waste emissions.

Application of Polymer Inclusion Membranes Doped with Alkylimidazole to Separation of Silver and Zinc Ions from Model Solutions and after Battery Leaching

“…In hydrometallurgical processes, solid waste-containing metals, including silver and zinc, are comminuted and then leached [22,23]. For leaching silver, nitric acid is most commonly used [24]. Additionally, attempts were made to leach waste with thiourea and its derivatives [25].…”