Copper ions can catalyze reduction of manganese dioxide by carbon monoxide in ammonia solution. The paper studied on the reduction ammonia leaching process of ocean Co-Mn polymetallic ores, such as the polymetallic nodules and the cobalt-rich crust. The self-catalysis reduction ammonia leaching was carried out, in which the copper ion leached out of the raw materials, the Co-Mn polymetallic ores, was taken as the catalyst and CO as the reducing agent. The concentration of copper in the leaching solution has great effect on the oxidation-reduction reaction rate, and the reaction rate is very fast when the concentration of copper is more than 8g/L. By a suitable mixture ratio of polymetallic nodules to cobalt-rich crusts, the self-catalysis reduction ammonia leaching could be realized. At the condition that polymetallic nodules to cobalt-rich crust 3:1, temperature 45° C and the leaching solution with more than Cu 9g/L, Ni 13g/L, and Co 3.5g/L, the average leaching extractions of nickel, cobalt and copper are 94%, 86% and 93% respectively in continuous leaching process.

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