Study On Electrochemistry Flotation Behavior Of Chalcopyrite-Sphalerite

The mineral resources of our country are abundant, while the poor, fine and complicated ores take up a large proportion, which makes the ore dressing work increasingly harder, especially for Cu-Zn intergrowth mineral. Copper ion is the activator of sphalerite, so flotation separation of the two minerals is hard. Therefore, in this case, the author searches after the electropotential control flotation separation feasibility of the two minerals.In this paper, with chalcopyrite from Jiangxi Dexing Copper Mine and sphalerite from Tsinghai Xitieshan Lead-zinc Mine as investigated subjects, the influence of extrocontral potential towards the floatation behavior of chalcopyrite and sphalerite is researched, and the best separation conditions of potential regulation and control flotation separation of chalcopyrite and sphalerite are found; at the same time, the influence of grinding process towards ore pulp potential and floatation behavior of chalcopyrite and sphalerite is researched, and the flotation separation experiment of protogenic potential regulation and control flotation separation is done; through electrochemistry test, surface electrochemistry reaction of chalcopyrite and sphalerite and lyophobic product are analyzed. Mainly research findings are as following:1. Chalcopyrite and sphalerite can be separated without collector in the idea thermodynamic system, however, in practical floatation ore pulp system, effective segregation of chalcopyrite and sphalerite is difficult.2.Under the condition of alkaline medium, low potential and collector-adding, extrocontrol potential regulation and control floatation is in favor of the flotation separation of chalcopyrite and sphalerite. Z-200 is a favorable collector for the separation of copper and zinc. Under the conditions that [Z-200]=5mol/L, pH=10.05, the best floatation potential of chalcopyrite and sphalerite is-48mV～-210mV。When Eh=-200m V, the copper recovery in copper concentrate can reach 84.40% whereas zinc 24.29%. Matching external control potential and traditional flotation factors, we can find that, under the conditions that [Z-200]=5mol/L, pH=10.05, and adding ZnSO4 as regulator, chalcopyrite and sphalerite floatation separation potential range are enlarged, reaching-30mV～-240mV。As a result, the flotation separation data is improved, and the separation effect is better. When Eh=-200mV, the copper recovery in copper concentrate can reach 94.75% whereas zinc lower to 17.97%.3.When grinding with porcelain media, ore pulp potential of chalcopyrite and sphalerite lowers with the rising of pH; when grinding with iron media, ore pulp potential of chalcopyrite and zinc rises and then falls with the rising of pH. Prolonging grinding time can lower ore pulp potential. The addition of collector also lowers the ore pulp potential, while the decreasing amplitude is small.4. The influence of ore pulp pH towards sphalerite floatation is great and zinc recovery rate falls rapidly with the rising of pH. Grinding with porcelain media, prolonging grinding time can raise recovery rate of chalcopyrite and sphalerite. Grinding with iron media, prolonging grinding time can lower recovery rate of chalcopyrite and sphalerite and the influence to sphalerite is larger. For chalcopyrite, no matter grinding with porcelain media or iron media, the floatation recovery rate when adding collector in mill is higher than that in flotation cell; for sphalerite, no matter grinding with porcelain media or iron media, the floatation recovery when adding collector in the flotation cell is higher than that in mill.5. The best flotation separation conditions by protogenic potential regulation and control of hand mixing ore are as following:selecting iron ball as milling medium, adding the medicament directly into mill, initial pH=11, grinding time 10mins, [Z-200] 0.5×10-4mol/L, potential of ore pulp Eh=-63 mV. The separation result is that copper recovery rate in copper concentrate is 87.43%, zinc 26.61%.Copper occupancy in zinc concentrate is 12.57%. If appending a little ZnSO4 as depressor of zinc, the flotation separation effect by protogenic potential regulation and control could be better, copper recovery rate in copper concentrate rising to 91.66%, whereas zinc occupancy down to 19.03%; The zinc recovery rate in zinc concentrate can reach 80.97%, at the same time, copper occupancy lowers to 8.34%.6. With the rising of pH value, the corrosion potential Ecorr of chalcopyrite makes for negative side, and corrosion current density Icorr rises as well, which shows that alkaline medium is in favor of anode reaction and can increase the electrochemical reaction rate; with the rising of pH value, corrosion potential Ecorr of sphalerite makes for negative side, whereas corrosion current density Icorr also weakens, which shows that alkaline medium is in favor of anode reaction, however, the generation of large amount of hydrophilic sediment at mineral surface lowers the electrochemical reaction rate at sphalerite surface. In a large range of pH, sulfur element S0 exists in the ostensible oxidative product of chalcopyrite, however, in alkaline medium, the amount of sulfur S0 produced is not so much. In acid medium, sulfur element S0 exists in the ostensible oxidative product of zinc ore, and it is stable.In alkaline, especially strongly alkaline medium, strong oxygenation occurs for sphalerite, and stably present sulfur element S0 cannot generated. It can be inferred from mineral crystal construct and adsorptive capacity test that Z-200 chemisorbs to the surface of chalcopyrite, and chemisorptions as well as physisorption exists at sphalerite surface.