Low-grade Copper-containing Purple Sulfur Nickel Ore Flotation Tests

Bulk flotation and preferential flotation are the main processing technique of Cu-Ni sulfides. Due to the complex ore properties, suitable processing technique is obtained after the investigation of ore properties and tentative tests. Pentlandite is common in Cu-Ni sulfide ores, but violarite is less. Therefore, resource efficient utilization can be achieved by exploring and summing up experience continually.Low grade Cu-Ni sulfide ores from Yunnan province, especially violarite, had been studied in this paper. Ore properties were analysed by some testing methods, such as main composition of the raw ore, chemical phases of copper and nickel, XRD and so on. The results indicated that the content of Ni was 0.54%, the distribution rate of sulphide ores was 88.89%, mineral was mainly violarite, and the content of Cu was 0.38%, the distribution rate of sulphide ores was 97.68%, mineral was mainly chalcopyrite. Gangue consists of silica which possed 40.04%, magnesium oxide which possed 11.66%, and calcium oxide which possed 9.15%. Due to metallic minerals were included reciprocally and appear sparse, it was difficult to dissociate.Due to the complex ore properties, different methods are obtained. The main methods include preferential flotation and bulk floatation. Based on the investigation of ore properties, firstly, conventionally tentative tests, including bulk floatation and preferential flotation, were carried out and flotation flowsheet was ensured. The result of tentative tests indicated that bulk floatation was considered as the feasible program, but preferential flotation was not. The result of preferential flotation indicated that part of nickel minerals was still easy to float under the condition of high depressant dosage and low collector dosage. It also indicated loss rate of nickel was relatively high due to depressed nickel was difficult to activate. Order to avoid the disadvantage of preferential flotation, the anthor put iso-flotability flowsheet forward. And it was the other program.After obtaining optimum condition of bulk floatation,closed-circuit test was carried out,including single-stage roughing, two-stage scavenging and single-stage cleaning.Finally,nickel concentrate of eight levels was obtained,in which the content of Ni was 4.14%, recovery of Ni was 73.90%,and the content of Cu was 3.81%, recovery of Cu was 85.00%, the content of MgO was 7.64%.After confirming reagent system and flowsheet structure of iso-flotability, the copper concentrate, nickel concentrate I and nickel concentrate II were obtained:in the copper concentrate, the content of Cu was 18.43%,recovery of Cu was 69.97%;in the nickel concentrate I, the content of Ni was 3.86%, recovery of Ni was 45.96%and the content of MgO was 9.09%;in the nickel concentrateâ…¡, the content of Ni was 3.80%, recovery of Ni was 23.17% and the content of MgO was 11.79%.Mixed nickel concentrateâ… withâ…¡, nickel concentrate of nine levels was obtained, the content of Ni was 3.83%, recovery of Ni was 69.13%, the content of MgO was 10.00%,and the content of Cu was 0.58%, loss rate of Cu was 15.68% in the nickel concentrate.Therefore, compared the bulk floatation with iso-flotability flowsheet, the latter was consided as the optimum technical route for the low-grade Cu-Ni sulfide ores.