Improvements in or relating to the concentration of cobalt-nickel ores

摘要

In a method of concentrating the sulphides of nickel and cobalt from an ore containing nickel, cobalt and iron sulphides, an aqueous pulp of the ore is conditioned with a selective collector for the nickel and cobalt sulphides, and a selective depressant for the iron sulphide, which depressant comprises an alkali ferricyanide and/or an alkali ferrocyanide together with an oxidizing agent such as an alkali permanganate and/or dichromate, and then subjected to froth flotation. Xanthate promoters and higher aliphatic alcohol frothers have been found satisfactory for the flotation of the nickel and cobalt sulphides and sodium and/or potassium ferrocyanide with sodium or potassium permanganate or dichromate for the depression of the iron sulphide. The pulp may be given a preliminary alkaline flotation at pH 9-10 to remove copper and lead.