Study On Activation Flotation Behavior And Mechanism Of Cu-Zn-Sulfide Ore Inhibited By Cyanide Sodium

The cyanide tailings produced by cyanide gold extraction contain a lot of valuable metals such as copper,lead,zinc and gold and silver which have not been recovered,and have high recycling value.There are few researches on activation recovery of copper,lead,zinc and sulfur from cyanide slag at home and abroad and the research on mechanism is not enough.As for the recovery of useful minerals from cyanide residue,the traditional activation reagents have disadvantages such as high cost,large dosage and poor activation effect,so it is necessary to develop new activation reagents.In this paper,the flotation test was carried out to study the activation effect of hydrogen peroxide,persulfate,ferrate,pyrosulfite,copper sulfate and their combination agents on the copper,zinc and sulfur sulfide ore inhibited by cyanidation.The feasibility of inhibition and activation was theoretically analyzed by electrochemical method,and the activation mechanism of activator on cyanide-inhibited sulfide ore was analyzed by infrared spectrum,XPS,Zeta potential and EPR detection methods.Flotation tests show that pyrite,chalcopyrite and sphalerite can all be deeply inhibited by sodium cyanide.When pH=8.5-9.5,the recovery rates of the three minerals decrease to less than 10.5%.Single and combined reagents can activate the three suppressed sulfide ores,and the recoveries can be restored to 80%-95%.Among them,the dosage of strong oxidant should be controlled to prevent excessive oxidation of minerals.Combined reagents can greatly reduce the dosage of reagents,it is recommended that hydrogen peroxide/copper sulfate/pyrophosphate,persulfate/ferrous sulfate and pyrosulfite/copper sulfate as the activator,the dosage is small,the activation effect is better.The results of EH-PH diagram and thermodynamic calculation show that the groups of sulfide ores inhibited by sodium cyanide can be divided into metal cyanide complexes.Reduction potential in activator were higher than the CN^-oxidation potential,activator react with CN^-the gibbs free energy change of values are less than zero,and than reaction with mineral activator of gibbs free energy change value is small,activator can spontaneously and CN^-response,and priority and CN^-reaction,when excess hydrogen peroxide,persulfate and ferrate,further oxide minerals.The change value of Gibbs free energy in the reaction of pyrosulfite with minerals is greater than 0,indicating that it cannot react with minerals and is conducive to the activation of sulfide ore.Zeta potential analysis showed that the surface potential of pyrite,chalcopyrite and sphalerite decreased significantly,indicating that Na CN chemically adsorbed on the mineral surface and reduced the floatability of minerals,while the activator can destroy the adsorption of CN^-,restore the surface potential of minerals and activate minerals.The results of infrared spectroscopy and XPS show that the corresponding cyanide complex peaks appear on the surface of pyrite,chalcopyrite and sphalerite,and the chemical adsorption of CN^-occurs on the surface of pyrite,chalcopyrite and sphalerite after adding sodium cyanide.However,after activation of the activator,the metal cyanide complex peak weakened or disappeared,in which the activation of sodium metabisulfite,the surface of the mineral CN^-into SCN^-,weaken the inhibition of CN^-.After the activation of the highly oxidizing activator,part of Fe on the mineral surface is oxidized to Fe₂O₃ and Fe₃O₄,and part of S is oxidized to the high-priced SO₄^2-.EPR shows that the SO₄^-·and HO·radicals produced by the advanced oxidation system composed of pyrite and persulfate,persulfate/ferrous sulfate and hydrogen peroxide can help to destroy the adsorption of sodium cyanide on pyrite.