| Ores containing zinc oxide are important components of zinc ore resources,and for a long time,zinc sulfide mineral,which is common and easily utilized,is one of the main raw ores for people to get zinc resources.However,ores containing zinc oxide have not been effectively utilized because of the difficulties in their extraction and utilization process.As the main mineral of zinc oxide ore,hemimorphite is one of the most difficult minerals to be upgraded because of its strong hydrophilicity.At present,the recovery of hemimorphite is mainly by "sulphidizing-amination flotation",and meanwhile,this technology still has the problems of low vulcanization degree,large amount of reagent consumption and low recovery.Therefore,it is of significant value to make various attempts to pretreat hemimorphite,in order to enhance the flotation efficiency of hemimorphite.This paper is based on the study of hemimorphite,with the aid of pure mineral flotation tests,bench-scale flotation tests,solution chemical analysis,zeta potential measurements,infrared spectrum and XPS tests.The effect of Pb2+ in strengthening the sulfuration flotation of hemimorphite was studied.Along the process,the changes in zeta potential,element composition and valence state of hemimorphite surface were detected,hoping to explore the relevant mechanism.The main conclusions are as follows:The results of pure mineral flotation tests showed that the effects of five kinds of metal ions(Pb2+?Zn2+?Cu2+?Mg2+?Ca2+)on the recovery of hemimorphite by sulfuration flotation were different.Different rules were correspondingly presented when the concentration and type of metal ions changed.Among them,Pb2+ had the most significant influence on the sulphide flotation of hemimorphite,and could increase the recovery of hemimorphite by 10%?15%.The results of the solution chemical analysis showed that the distribution rate of each component in the solution was greatly influenced by the pH value of the pulp.The optimum floatation pH range of hemimorphite was 8-10,and the concentration of components beneficial for the flotation of hemimorphite was higher under this pH interval.With the help of zeta potential,UV spectrum,infrared spectrum and XPS measurements,the flotation mechanism of Pb2+ in hemimorphite flotation by sulfuration was studied.The ability of Na2S to activate the flotation of the hemimorphite was to increase its surface negative electricity,which was in favor of the subsequent reaction of eighteen amines and other cationic collectors.It was found that during the flotation process,the hydrophilic complex of hemimorphite(Zn(OH)2 complex)was replaced or covered by the lead hydroxyl complex(Pb(OH)2 complex),and then,the activation occurred.Pb2+ had the following points for the strengthening of the hemimorphite flotation:1)Destruction of hydrated layer;2)Increasing the number of active points;3)Changing the surface potential of minerals.Hemimorphite was the main occurrence mineral of ores containing zinc oxide in a lead-zinc mine in Huili,Sichuan province.In view of the characteristics of this ore,experimental study on the flotation recovery of zinc oxide by " sulfuration-amine method" was conducted,and the effect of Pb2+ pretreatment on the recovery of zinc oxide was also studied with attention.The experimental results showed that with Pb2+pretreatment,the recovery of zinc oxide was increased by 5%?6%,showing that a good result was achieved. |
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