Effect Of The Oxidation Of Chalcopyrite Surface On Flotation Performance

The oxidation of chalcopyrite affected its surface properties and floatability,especially when it co-exists with other sulfide ores,caused the decrease of the grade and recovery of copper concentrate.In this work,chalcopyrite was pretreated with hydrogen peroxide to simulate different degrees of oxidation in real ore.The effect of surface oxidation of chalcopyrite on it’s flotation performance was studied by flotation test,XPS analysis,ICP test,and reagent adsorption test of FTIR and UV-visible to determine the reason of low grade and recovery of copper concentrate.The main conclusions are as follows:(1)The effect of the oxidation pretreatment on floatability of chalcopyrite was studied.The changes the concentration of hydrogen peroxide,soaking time of hydrogen peroxide and drying temperature and the results of flotation tests showed that the recovery and floatability of chalcopyrite decreased after oxidation.(2)The mechanism of chalcopyrite surface oxidation has been studied:The surface of chalcopyrite was mainly covered by iron hydroxyl substances after the oxidation pretreatment,caused the increased hydrophilicity and decreased floatability;After oxidation,sulfate radical formed on the chalcopyrite surface and a large amount of copper ions dissolved;The surface oxidation of chalcopyrite has little effect on the amounts of xanthate adsorption,and xanthate mainly adsorbed on the mineral surface in the form of dixanthate after oxidation.(3)The recovery of the floatability of oxidized chalcopyrite and flotation separation of oxidized chalcopyrite and activated pyrite by copper ion were studied.The results of flotation test showed that sodium sulfide,triethanolamine and sodium citrate can improved the floatability of oxidized chalcopyrite to a certain extent,butyl xanthate and ethyl thiamine and their combination had better collection ability of oxidized chalcopyrite and improved its floatability.Ca O inhibited pyrite activated by copper ions,and had little effect on oxidized chalcopyrite,which was beneficial to flotation separation of the two.(4)The surface oxidation of chalcopyrite resulted in the dissolution of a large number of copper ions,which increased the difficulty of copper and sulfur separation and reagent consumption.For the real ore containing copper sulfide and oxidized copper sulfide,the sulfide part and the oxidized part respectively recovered after roughing,and finally the concentrate of Cu grade 19.01% and recovery 61.96% was obtained,and the flotation recovery of copper was preliminarily realized.