Influence Mechanism Of Surface Oxidation On Pyrrhotite Flotation Behavior

In the flotation of polymetallic sulfide ores,the presence of pyrrhotite will have a significant impact on the flotation separation of associated copper,lead,zinc and other sulfide ores.According to the difference in mineral properties,the use of surface oxidation regulation technology can amplify the difference in hydrophobicity between different sulfide minerals,thereby separating the minerals.This technology has been used in the flotation separation of sulfide ores,but it is less used for pyrrhotite.In addition,there are few studies on the influence mechanism of surface oxidation on the flotation behavior of pyrrhotite.Therefore,this paper takes monoclinic pyrrhotite as the research object,studies its flotation behavior under different collection systems,and investigates the influence of surface oxidation on its flotation behavior.The adsorption amount test,flotation kinetic calculation,infrared spectroscopy and XPS test are used to reveal the influence mechanism of surface oxidation on flotation behavior of pyrrhotite.The research results can provide theoretical guidance for the efficient separation of pyrrhotite-bearing sulfide ores.The flotation test results show that the flotation recovery of monoclinic pyrrhotite first increases and then decreases with the increase of the p H value of the pulp under the system of butyl xanthate,ethyl thiocarbamate and ammonium dibutyl dithiophosphate.The floatability of monoclinic pyrrhotite is better when the p H value of pulp is 6-10.The best floatability is when the p H of the pulp is 10.Compared with other collectors,butyl xanthate has stronger ability to collect monoclinic pyrrhotite.Potassium permanganate,sodium hypochlorite and hydrogen peroxide can inhibit the floating of monoclinic pyrrhotite,and the inhibition ability successively weakens in the best flotation condition.In the combined oxidants of sodium hypochlorite + potassium permanganate and sodium hypochlorite + hydrogen peroxide,the flotation recovery rate is similar to that when sodium hypochlorite is used alone,and is lower than that when sodium hypochlorite is used alone,and sodium hypochlorite is the main inhibition.In the combined oxidant of potassium permanganate + hydrogen peroxide,the change rule of flotation recovery rate is similar to that of single use of hydrogen peroxide,and the inhibition of hydrogen peroxide is the main one.Potassium permanganate and hydrogen peroxide may undergo redox reactions,so the synergistic inhibition effect is poor.Among the three combined oxidants,only sodium hypochlorite + hydrogen peroxide has a better flotation inhibition effect than the single oxidant.The test results of adsorption amount,flotation kinetics and infrared spectroscopy indicate that hydrophobic double xanthate may be formed after the interaction between the mineral and butyl xanthate,and the double xanthate will adsorb on the mineral surface to enhance the hydrophobicity of the mineral.However,the oxidant will weaken the adsorption between the mineral and butyl xanthate.It is reflected in the adsorption amount of butyl xanthate by the mineral after the action of the oxidant is reduced to varying degrees,the flotation rate of the mineral is greatly reduced,and the absorption peaks of butyl xanthate in the mineral disappear or shift.The XPS detection results show that the mineral may react with butyl xanthate to form iron xanthate on the surface.After the mineral is oxidized by oxidants,various oxidation products(iron hydroxide and sulfate,etc)are produced,which lead to the weakening of the interaction between the mineral and butyl xanthate,so the mineral is inhibited.After the mineral is oxidized,the surface element binding energy is displaced,and the oxidants can be sorted according to the displacement value: sodium hypochlorite > potassium permanganate > hydrogen peroxide,sodium hypochlorite +potassium permanganate > sodium hypochlorite + hydrogen peroxide > potassium permanganate + hydrogen peroxide.The rule is similar to the oxidizing ability of the oxidant under the same p H condition.After the mineral is oxidized,the Fe2 p and S2 p contents decrease,so the mineral may be dissolved.The change of the molar ratio of sulfur and iron atoms on the surface of the mineral after the action of butyl xanthate or oxidant is the reason for the change of its floatability.