Copper ore is the composite of copper's sulfide, oxide and other minerals. When reacting with vitriol, glaucous copper sulfate forms. Natural copper ore has various colors. Brass is bright yellow. Bornite is dark copper red and when it is oxidized, it would turn bluish violet. Chalcocite is lead gray while the copper sulphide is indigo blue.
Two common floatation methods
1. Floatation suitable for disseminated copper ore
Usually, the beneficiation process is simple. Firstly, ore is ground until the material whose size is around 200mesh takes up 50%~ 70%. Next, the material would undergo coarse separation once, careful separation twice or three times and scavenging once or twice. If the copper ore is fine, phased grinding and separation process is adopted. For processing bornite, the rough concentrate would be ground again and sent to be separated carefully. Through coarse grinding, coarse separation and scavenging, coarse rough concentrate can be got which would be ground once more and separated carefully to produce high-grade copper concentrate and sulfur concentrate.
2. Floatation suitable for dense copper ore
Because the brass and pyrite coexist in the dense copper ore, the brass is easy to be activated by the secondary copper minerals and the high content of pyrite is difficult to be separated. During separation, copper concentrate and sulfur concentrate need to be selected simultaneously. Usually, the tailing after the copper concentrate is separated is sulfur concentrate. If the gangue content is above 20%~25%, to get sulfur concentrate, it is necessary to separate the gangue further. For processing of dense copper ore, two-stage or even multi-stage grinding is needed and the requirement of fineness must be detailed.