Experimental research and application practice on copper-molybdenumseparation in the high⁃altitude copper polymetallic mine in Lhasa,Tibet

The copper⁃molybdenum separation operation in the high⁃altitude copper polymetallic ore concentratorin Lhasa,Tibet,only uses sodium hydrosulfide as an metal mineral depressant. This causes the residual HS in the re⁃turn water to enter the production water system,causing the pH of the water to exceed 12,which directly affects thefloating of copper⁃bearing minerals in the front⁃end copper⁃molybdenum mixed flotation operation. When the cop⁃per grade is 0.948% and the molybdenum grade in raw ore is 0.032%,the annual copper recovery is only 87.17%and the molybdenum recovery is 33. 79%. In order to avoid the impact of HS in the return water in the cop⁃per⁃molybdenum separation operation on the floating of copper minerals in mixed flotation, the process mineralo⁃gy characteristics of the copper⁃molybdenum mixed concentrate were studied to screen out the inorganic and organ⁃ic combined depressant for copper minerals and environmentally friendly depressant for non⁃copper sulfide mineralsin mixed concentrate. For chalcopyrite,bornite,chalcocite and multi⁃copper minerals,sodium hydrosulfide and sodi⁃um thioglycolate are used as jointly depressant,non⁃copper metallic minerals and non⁃metallic minerals are targeted tobe depressed, which improves the separation effect of copper⁃molybdenum separation operations and greatlyreduces the dosage of sodium hydrogen sulfide by 57.39%,and its unit consumption is reduced to 671 g / t. By adding221 g / t of sodium thioglycolate for depressing copper minerals and 13.53 g / t of organic depressant AT⁃208 for sul⁃fide minerals,the impact of the single use of sodium hydrosulfide inorganic agent on front⁃end copper and molybde⁃num mixed flotation indicators was avoided. When the copper grade is 0.934% and the molybdenum grade in raw oreis 0.025%,the obtained annual copper recovery is 90.102% and the molybdenum recovery is 44.363%. The copperand molybdenum recovery have increased by 2.932% and 10.573% respectively compared with before optimization.The new environmentally friendly organic agents exert their respective targeted depressing effects,which can not onlyreduce agent consumption, ensure the stability of the pH value of mineral processing return water, but also a⁃chieve comprehensive and efficient recovery of mineral resources,providing technical support for high⁃quality develop⁃ment of enterprises and improving their core competitiveness.