19 - Flotation of Oxide Copper and Copper Cobalt Ores

Abstract

The process of flotation of oxide copper and copper cobalt ores involves two basic flotation methods: fatty acid flotation of oxide copper minerals from siliceous ore and sulphidization of oxide copper minerals followed by flotation using sulfhydryl collectors, such as xanthate from carbonate ores. The flotation characteristics of the oxide copper minerals from natural ore are dependent on several main factors, for instance, chemical composition and physical structure of the oxide copper minerals and the ionic composition of the slurry phase. The oxide copper minerals are often porous, and in some cases they are water-soluble. Some of the oxide minerals tend to slime during grinding, and flotation of fine oxide minerals is rather difficult. Floatability of malachite is one of the most important oxide copper minerals for production of copper from oxide ores using flotation. Cationic flotation of malachite, using mono- and diamines in alkaline pulp, is also examined in this study. Malachite floats readily using monoamines under laboratory conditions. The floatability of oxide cobalt minerals is strongly influenced by the presence of small amounts of copper in its crystalline structure. From the point of view of flotation properties, the cobalt minerals can be classified in two main groups: crystalline varieties with compositions closely responding to the formula CoO·OH, and crypto- crystalline or amorphous varieties that contain various amounts of copper–nickel–iron and also bivalent cobalt.