Sulfuric acid leaching of ocean manganese nodules using phenols as reducing agents

摘要: Abstract Pacific Ocean manganese nodule samples were leached with dilute sulfuric acid in the presence of phenol type aromatic reducing agents. Six phenols, including hydroxybenzene, o-dihydroxybenzene, m-dihydroxybenzene, p-dihydroxybenzene, o-trihydroxybenzene and m-trihydroxybenzene, tested. The results indicated that all tested phenols effective agents significantly increased extraction Mn, Cu, Ni, Co from nodules. At a dosage 0.25 ∼ 0.4 grams 0.925 H 2 SO 4 per gram nodules, over or nearly 95% Ni could be extracted 10 20 minutes an aqueous slurry containing about 20% nodule, under ambient temperature pressure. In absence agents, Cu was 65% below 20%. ESCA, TLC UV/VIS spectroscopic analyses Mn nodules reduced medium, while oxidized to p-benzoquinone.