How to beneficiate mixed copper ore?

About 90% of copper in nature comes from sulfide deposits, mainly chalcopyrite, which accounts for about half of all copper production. In a few deposits, copper also occurs in the form of copper oxide. In addition to this, there are mixed forms of the two, which are mixed ores of copper oxide and copper sulfide minerals. So, how to choose mixed copper ore?

The oxidized copper deposit in Dali, Yunnan, China contains 0.69% copper (0.46% and 0.23% copper sulfide and oxide minerals, respectively) and 11.24 g/t silver. The ore is upgraded through a sulfidation process and then subjected to xanthate collector flotation. Although it is a mixed ore, the focus is on the flotation of sulfide minerals. Finally, after two rounds of roughing, two rounds of cleaning, and one purge in closed-circuit tests, a concentrate with a copper content of 20.20% and a recovery rate of 68.11% was obtained.

There are also mixed copper mines in Guizhou, China. The ore contains 1.15% copper. The sulfide minerals are chalcopyrite, chalcocite, copper blue and bornite. The oxide minerals are malachite and golden malachite. The gangue minerals are mainly quartz, Dolomite and mica. For this ore, we use oleic acid as a collector and pine oil as a frother for reverse flotation to retain the copper oxide minerals in the pulp. The results showed that about 90% copper recovery and 10% copper grade could be achieved using 1.5 kg/t oleic acid collector. Copper minerals lost in froth products can be recovered by washing the concentrate under the same flotation conditions.

The copper oxide minerals in the Mexican mixed copper ore are ransbeckite and malachite, the copper sulfide minerals are chalcopyrite, and SiO2 is the main gangue mineral. The total copper content is 1.19%, of which copper oxide is 0.84% and copper sulfide is 0.35%. We performed a combination of flotation and leaching. Using sodium sulphide and butyl xanthate, a concentrate was obtained with a copper grade of 19.01% and a recovery of 35.02%. After flotation and leaching are completed, the final yield is 89.18%, which is better than single leaching or flotation process. It was concluded that the combination of flotation and leaching is beneficial for the beneficiation of mixed copper ores in Mexico.

Therefore, the "flotation-stirring-leaching-solvent extraction-electric extraction" process route can produce 99.9% pure copper.