Sulfuric acid leaching of ocean manganese nodules using aromatic amines asreducing agents

Sulfuric acid leaching of ocean manganese nodules was carried out using aro matic amines as reducing agents. Seven aromatic amines were tested and they were: aniline, o-phenylene diamine, o-aminobenzoic acid, o-nitroaniline, p -amino toluene, p-aminobenzene sulfonic acid and 1-naphthylamine. Ar ambien t temperature and pressure, these aromatic amines markedly! increased metal extraction from the nodules. Generally, extraction of Mn, Ni and Co increa sed with increasing reductant dosages. However, for most of the tested arom atic amines, high reagent dosages resulted in rapid decrease in copper extr action, with the exception of p-aminobenzene sulfonic acid. The p-aminobenz ene sulfonic acid was found to be the most effective reducing agent for the extraction of Mn, Ni, Cu and Co from the manganese nodules. (C) 2001 Publi shed by Elsevier Science Ltd. All rights reserved.