METHOD FOR LEACHING COBALT FROM OXIDISED COBALT ORES

摘要

A method for leaching cobalt from a non-lateritic oxidised cobalt ore, the method comprising the method steps of: curing the non-lateritic oxidised cobalt ore to be leached through the application of an aqueous solution of a cobalt reducing agent selected from the group: iron (II) salts, sulfite salts, sulfur dioxide, and combinations thereof; at a pressure of between about atmospheric pressure and about 5 atmospheres, at a temperature between about 5 °C and about 65 °C; wherein the pH of the aqueous solution of the cobalt reducing agent is between about 1.0 and 10.0; and wherein the relative volumes of the aqueous solution of the cobalt reducing agent and the non-lateritic oxidised cobalt ore to be leached are such that the combination of the aqueous solution of the cobalt reducing agent and the non-lateritic oxidised cobalt ore to be leached forms a mixture with a solids content not less than about 100 g/L of aqueous solution; substantially retaining the aqueous solution of the cobalt reducing agent in contact with the non-lateritic oxidised cobalt; and leaching the cured ore at a pressure of between about atmospheric pressure and about 5 atmospheres, at a temperature between about 5 °C and about 65 °C, through the application of an ammonium carbonate solution containing free ammonia thereby producing a pregnant leach solution; then passing the pregnant leach solution resulting to a means for cobalt recovery.