Study On The Comprehensive Flotation Recovery Test Of A Porphery Copper-molybdenum Ore From Heilongjiang Province

The copper-molybdenum resources in China are rich,however,copper-molybdenum ores usually have the characteristics of complex compositions,fine particle size of useful minerals and high sulphur contents.In addition,Kerosene,a traditional molybdenum collector,has the disadvantages of narrow sources,high costs,and weak flotation performances to copper.These two aspects mentioned before restrict the comprehensive recovery of copper and molybdenum.For better understanding the properties and achieving the beneficiation of a copper-molybdenum ore from Heilongjiang province,the flotation experiments of pure and actual minerals were performed through selecting BZ-1 and sodium thioglycollate as collector and depressor,respectively.The mechanism of interaction in flotation was revealed adopting modern testing technologies of adsorption density tests,Zeta potential measurements,solution chemistry analyses and fourier ransform infrared spectroscopy?FTIR?analyses.The studies have potential values for the development of new molybdenum collectors and processes.The pure mineral experiments show that BZ-1 has the characteristics of strong collecting ability to chalcopyrite and molybdenite,but weak collecting ability to pyrite and good pH adaptability.The there regulators used pure mineral experiments have a order of depression performances to pyrite:lime?sodium hydroxide?sodium carbonate.In the pretreatment of rough concentrate,the desorption of BZ-1 from the surfaces of chalcopyrite is easier than that of kerosene and butyl xanthate.Meanwhile,the desorption effects using sodium sulfide is better than that of activated carbon.The chalcopyrite after the pretreatment can be depressed effectively.Actual mineral experiments were preformed using BZ-1 and sodium thioglycollate as copper-molybdenum collector in rough flotation and depressant of chalcopyrite after the pretreartment,respectively.Mo and Cu grade of actual ore are0.114%and 0.016%,respectively.And Mo and Cu grade of the molybdenum concentrate obtained from closed circuit experiments are 52.45%and 0.147%,respectively,Mo recovery is 94.78%.Cu grade and recovery of the copper concentrate are 21.71%and 62.24%,respectively.The mechanism study shows that the differences in the adsorption capacity of BZ-1 among molybdenite,chalcopyrite and pyrite is the reason for their different floatability in roughing.As a result of the selective adsorption of sodium thioglycollate,the chalcopyrite pretreated was depressed.Zeta potential measurements and solution chemistry analyses indicate that the adsorption of HS^-made the Zeta potentials of molybdenite and chalcopyrite more negative,meanwhile,that of chalcopyrite decreased more than molybdenite.Therefore,the desorption of BZ-1from the surfaces of chalcopyrite is due to the selective adsorption between HS^-and BZ-1.The interaction between sodium thioglycollate and molybdenite is very weak,and the zeta potentials of chalcopyrite decreased due to the co-adsorption of HSCH₂COO^-and SCH₂COO^2-.Pyrite was inhibited using BZ-1 as the collector due to the adsorption and covering of CaCO₃,CaSO₃,CaSO₄ and Fe?OH?₃ onto mineral surfaces.FTIR analyses indicate that the adsorptions of BZ-1 on the surfaces of molybdenite,chalcopyrite and pyrite occurred physically,while that of sodium thioglycolate on chalcopyrite surfaces is chemisorption.Both-S^-and-COO^-can adsorb onto the chalcopyrite surfaces simultaneously.When-S^-adsorbed on the surfaces of the chalcopyrite,the hydrophilic-COO^-belonging to the same molecule was outward,or-COO…H…OOC-formed as a result of H-bonding interactions.Similarly,when-COO^-adsorbed on the surfaces,-SH was outward,or-S-S-formed due to the oxidation between the-S^-of the molecule adsorbing on chalcopyrite surfaces and the-S^-on the other thioglycolic anion in solution,and the hydrophilic-COO^-was outward again.The adsorptions occurred between chalcopyrite and sodium thioglycollate made mineral surfaces hydrophilic and depressed effectively.