Magnetite commonly used mineral processing method for magnetic separation, but what if magnetite contains copper? Copper-bearing magnetite is widely distributed in the world and has large reserves. In addition to magnetite and hematite, this kind of ore is also associated with copper-based non-ferrous metal minerals, such as chalcopyrite, pyrite and cobaltite.
Common beneficiation processes of copper-bearing iron ore include floating-magnetic process, magnetic-floating process, magnetic separation-gravity separation combined process, stage grinding stage separation process, etc.
The flotation tailings after floating-magnetic process can directly enter the magnetic separation operation, while the magnetic separation tailings after magnetic-floating process need to be concentrated before entering the flotation operation, so the equipment investment such as sand pump and thickener is increased, and the production cost such as hydropower is increased. In addition, in the floating-magnetic process, copper recovery rate is higher.
Chinese scholars have done experimental research on Australian Cairn Hill magnetite containing copper and gold. Because the iron content in the raw ore is high, the copper content is low, and the content of other associated symbiotic metals is relatively low, the combined process of preferential flotation of copper, post-flotation of sulfur and tailings low-intensity magnetic separation of iron is adopted. In the small closed-circuit test, copper concentrate with copper grade of 21.15 %, copper recovery of 88.94 %, gold grade of 4.10 g / t and gold recovery of 49.50 %, iron concentrate with iron grade of 70.68 % and iron recovery of 92.14 %, and sulfur concentrate with sulfur grade of 40.58 % and sulfur recovery of 56.80 % were obtained.
For magnetite-based ores containing a small amount of copper, sulfur and other metals, magnetic-floating process is generally adopted. Magnetic separation enriches copper ore in tailings, creating conditions for the next flotation of copper. In the experimental study of the magnetic-flotation process of an iron-copper ore containing 26.30 % iron and 0.24 % copper in Yunnan, an iron concentrate with iron grade of 66.93 % and iron recovery of 56.28 % and a copper concentrate with copper grade of 20.79 % and copper recovery of 80.02 % were obtained.
The combined process of various beneficiation methods requires customized beneficiation schemes for different copper-bearing magnetite. For example, for the copper-iron ore with iron grade of 44.23 % and copper grade of 0.24 %, a qualified iron concentrate with iron grade of 60.12 % and recovery rate of 78.52 % and a qualified copper concentrate with copper grade of 22.13 % and recovery rate of 59.37 % were obtained by using the process of weak magnetic-strong magnetic-flotation-gravity separation.
The stage grinding stage separation process can discard part of the tailings in advance, reduce the amount of grinding in the lower grinding, thus reducing energy consumption and achieving the purpose of cost saving. Common stage grinding stage separation process includes: magnetic rough concentrate regrinding iron separation process, copper rough concentrate regrinding copper separation process, copper and iron rough concentrate regrinding copper and iron separation process.
The beneficiation production index of a copper oxide iron ore has been relatively low. The copper grade of copper concentrate is 12 % ~ 16 %, the copper recovery rate is 55 % ~ 65 %, and the flotation index is also relatively low. The modified beneficiation process adopts a new process of step flotation of copper sulfide and copper oxide and leaching of copper oxide flotation, which can greatly improve the beneficiation index of copper. Compared with the production process before modification, the copper grade of copper concentrate is increased by 5 % and the total copper recovery rate is increased by more than 20 %.
Above we introduced the copper magnetite commonly used several kinds of beneficiation process. In fact, The design and development of the beneficiation process should not be uniform or fetishistic, because there are no two mines in the world that are exactly the same, and any batch of ore has its own uniqueness. So for how to choose magnetite containing copper, we still recommend that you find a professional mineral processing factory to do an ore beneficiation test and based on the test results to develop a suitable program, in order to obtain better recovery and higher returns.
