Application of Ammoniacal Solutions for Leaching and Electrochemical Dissolution of Metals from Alloys Produced from Low-Grade E-Scrap

Abstract

Paper reports results of the research on the application of ammoniacal solutions (sulfate, chloride, carbonate) for hydrometallurgical treatment of smelted low-grade e-waste. Two Cu-Zn-Sn-Ag-Pb alloys were analyzed in details and discussed. Leaching of copper from the alloys was slow in sulfate solution, but the dissolution rate decreased in chloride and carbonate baths. Anodic alloys dissolution was uniform in sulfate and carbonate electrolytes, but high degradation of the material was observed in chloride bath. Chemical and phase composition of slimes and cathodic deposits produced during electrolysis were characterized. In all cases, separation of copper from other metals was found, but efficiencies of the processes were low.

Concept for a Hydrometallurgical Processing of a Copper‐Cobalt‐Nickel Alloy Made from Manganese Nodules

“…In this case, cementation of the copper through the less noble metals takes place (Eqs. (5)- (7)). However, the cemented copper is also leached by sulfuric acid according to Eq.…”

“…In a first experiment, the FeNiCuCo alloy provided by RWTH Aachen was leached with copper sulfate according to Eqs. (4)- (7). The high copper sulfate excess was chosen to prevent hydrogen gas formation.…”

“…The alloy produced by the pyrometallurgical process contains mainly the valuable metals copper, cobalt and nickel. Options for further processing for alloys are POX, ammonia leaching and anodically dissolving in acidic electrolytes .…”