Abstract:Mineral mixed by ocean polymetallic nodules and cobalt-rich crusts was used as raw material. Effects of mixture ratio of ocean polymetallic nodules to cobalt-rich crusts, concentration of ammonium sulfate, ammonia concentration, cuprous ion concentration and temperature on leaching rate of valuable metals were investigated in low temperature ammonia solution system with cuprous ions as catalyst and carbon monoxide as reductant. The results show that leaching rates of nickel, cobalt, copper and manganese are 97.15%, 93.68%, 92.64% and 20.90% respectively under the optimum conditions including ratio of cobalt-rich crusts of 25%, concentration of ammonium sulfate of 25 g/L, ammonia concentration of 120 g/L, cuprous ion concentration of 10 g/L, temperature of 50 ℃, and flow rate of carbon monoxide of 20 mL/min. Combined metallurgy process of ocean polymetallic nodules and cobalt-rich crusts is achieved, and the problem of low cobalt leaching rate in leaching of single cobalt-rich crusts by ammonia is addressed.