Effect And Mechanism Of Thermal Pretreatment On Flotation Separation Of Low Grade Copper-lead-zinc Sulfide Ore

Copper,lead and zinc are a large number of basic raw materials in short supply for the development of national economy and science and technology.Due to the poor resource endowment of copper lead zinc sulfide minerals in China,the surface properties of sulfide minerals are very similar due to the same electron source sulfur,which makes flotation separation difficult.In this paper,the surface oxidation mechanism and flotation separation behavior and mechanism of copper lead zinc sulfide minerals are studied by using thermal pretreatment method,combined with Fitr,contact angle,XPS,zeta potential and other test methods.The high-efficiency flotation separation method of copper lead zinc sulfide ores is explored,which provides theoretical basis and technical support for the high-efficiency separation and comprehensive recovery of copper lead zinc sulfide ores in China The operation support.The main research contents and results are as followsThe effect of thermal pretreatment on flotation behavior of copper lead zinc sulfide ore was studied.The results show that when the temperature of 170 ? is used for thermal pretreatment,the surface of chalcopyrite is strongly inhibited under the condition of pH > 9,with poor floatability and low flotation recovery;while the floatability of galena and sphalerite has little change,and the influence of thermal pretreatment and pH on flotation recovery is small.The effect of thermal pretreatment on flotation separation of copper lead zinc sulfide ore was studied.The results show that after thermal pretreatment at 170 ?,the flotation separation effect of CuPb,Cu Zn mixed minerals is good under the condition of pH > 9,while the flotation separation effect of Pb Zn,CuPbZn mixed minerals is poor.Thermal pretreatment can realize the effective separation of CuPb,Cu Zn sulfide minerals.The process flow of "copper lead mixed flotation,thermal pretreatment separation zinc separation from tailings" is adopted to preferentially flotation copper lead minerals.The mixed concentrate is pretreated at 200 ? for 4 hours before copper lead separation.Under the condition of raw ore containing 0.30% Cu,2.13% Pb and 3.33% Zn,copper concentrate with 21.25% Cu,4.38% Pb,5.72% Zn and 72.51% Cu recovery rate,lead concentrate with48.65% Pb,0.44% Cu,7.26% Zn and 81.67% Pb recovery rate,zinc concentrate with 46.13%Zn,0.51% Cu,1.49% Pb and 81.02% Zn recovery rate were obtained by small closed circuit test.Compared with the original process,the grade of copper concentrate is increased by5.53%,the recovery of copper is increased by 3.01%,the grade of lead concentrate is increased by 1.53%,and the recovery of lead is increased by 9.64%.FTIR,XPS,contact angle and zeta potential were used to test and analyze the surface properties of CuPbZn sulfide ore before and after thermal pretreatment.The results show that after heat pretreatment,butyl xanthate can still chemically adsorb on the surface of galena and sphalerite,and the surface potential of galena and sphalerite shifts negatively,while butyl xanthate has no obvious adsorption characteristics on the surface of chalcopyrite,and the surface potential of chalcopyrite does not shift negatively;at the same time,the surface hydrophobicity of chalcopyrite and sphalerite decreases greatly,but the change of galena is not obvious The surface oxidation of chalcopyrite,galena and sphalerite is weaker.When NaOH solution is added to the treated chalcopyrite slurry,the interaction between Fe³⁺ and OH-produces a strong hydrophilic Fe(OH)₃ colloid,which prevents the adsorption of butyl xanthate on chalcopyrite,resulting in the poor floatability of chalcopyrite.