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, were tested. The results indicated that all the tested phenols were effective reducing agents that significantly increased the extraction of Mn, Cu, Ni, Co from the nodules. At a dosage of 0.25 (similar to) 0.4 grams of the reducing agents and 0.925 grams of H2SO4 per gram of nodules, over or nearly 95% of the Mn, Cu, Ni and Co could be extracted in 10 (similar to) 20 minutes from an aqueous slurry containing about 20% manganese nodule, under ambient temperature and pressure. In the absence of the reducing agents, the extraction of Cu was about 65% and that of Mn, Ni and Co was below 20%. ESCA, TLC and UV/VIS spectroscopic analyses indicated that the Mn in the nodules was reduced in the presence of phenols in the acid medium, while the phenols could be oxidized to p-benzoquinone.


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    Title :

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


    Contributors:
    Zhang, Y. (author) / Liu, Q. (author) / Sun, C. (author)

    Published in:

    Minerals Engineering ; 14 , 5 ; 525-537


    Publication date :

    2001


    Size :

    13 Seiten, 22 Quellen




    Type of media :

    Article (Journal)


    Type of material :

    Print


    Language :

    English








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