Manganese ores are processed by adding the ore to an aqueous solution of acid and h2o2 to form a leach pulp. The pulp is agitated for a predetermined time at predetermined temperatures. The leach pulp is then separated into a solid fraction and liquid fraction containing solubilized metals. Thus, 30 g of minus 10-mesh cobalt-manganese crust was mixed with 200 ml of a water solution containing 3.4 Wt pct h2so4 and 1.2 Wt pct h2o2 at room temperature. The crust, obtained from the ocean floor of the U.S. exclusive economic zone in the Central Pacific Basin, assayed 6.07 pct mn, 11.3 pct fe, 0.19 pct CO, and 0.14 pct ni. After 1 h of agitation, the pulp was filtered and the filter cake was washed with fresh water. The combined filtrate and wash assayed 0.84 G/l mn, 0.42 G/l fe, 0.037 G/l CO, and 0.015 G/l ni. Distribution to the filtrate, in percent, was 95 mn, 28 fe, 96 CO, and 90 ni. The test was repeated using a synthetic seawater solution in place of fresh water with similar results.
U.S. Pat. 4,872,909, Oct. 10, 1989