Research On Selective Agglomeration Flotation Of Oxidized Digenite Fine Particles For Separation Of Copper And Sulfur

The effective separation and recovery of oxidized copper sulfide minerals fine particles has always been a technical problem in the field of mineral processing.Because of the small quality,fine grain,and strong hydrophilic surface,it is difficult for fine mineral particles to overcome the energy barrier between mineral particles and bubbles and can not effectively adhere to bubbles in the flotation process,resulting in difficulties in flotation recovery.In addition,the surface of fine copper sulfide minerals is easy to be oxidized.After being oxidized,the surface solubility of copper sulfide minerals increases greatly,which strengthen the interaction between copper sulfide minerals and further increase the difficulty of flotation separation and recovery of fine copper sulfide minerals.Therefore,taking fine-grained oxidized digenite and its common associated mineral pyrite as the research object,this paper studies the agglomeration flotation of fine-grained oxidized digenite and its application in copper sulfide separation from the perspective of improving the apparent particle size and floatability of fine-grained digenite.It is expected to provide a new technical means and theoretical basis for the efficient separation and recovery of fine copper oxide sulfur minerals in flotation production practice.The results of hydrophobic agglomeration flotation of fine-grained oxidized digenite show that after serious oxidation of fine-grained digenite,resulting in poor mineral floatability and slow floation speed.The mineral floatability can be improved by increasing the amount of butyl xanthate and sodium sulfide.But the sulfide flotation effect of fine oxidized digenite is better.The recovery of digenite can reach 88.73%when the dosage of sodium sulfide is1.25×10^-3mol/L.The agglomeration of digenite particles in pulp can be reflected by the results of optical microscope analysis and particle size tests.The results show that the dispersion degree of digenite particles is high after stirring in deionized water.Then,with the addition of different flotation reagents,aggregation groups with different particle sizes are formed between the particles of digenite.In particular,with the addition of sodium sulfide,butyl xanthate and terpineol oil,obvious aggregation behavior can occur.According to the EDLVO theoretical calculation results,strong hydrophobic gravity promotes the formation of large-size polymer groups.Therefore,the finely oxidized digenite can be effectively recovered after adding sodium sulfide and butyl xanthate.The results show that low amount of Fe³⁺have little effect on the sulfide flotation of fine oxidized digenite.But when the amount of Fe³⁺exceeds 5×10^-4mol/L,the flotation recovery and speed of digenite decreased significantly.The main reason is that Fe³⁺is mainly adsorbed on the surface of fine oxidized digenite in the form of Fe（OH）₃,which weakens the effective vulcanization of digenite,reduces the hydrophobicity of mineral surface,prevents the formation of hydrophobic polymer groups and leads to low flotation recovery and slow flotation speed of digenite.The flotation test results of fine oxidized pyrite show that with the increase of butyl xanthate dosage,the floatability of fine oxidized pyrite gradually increases.With the increase of the amount of sodium sulfide,the recovery of fine oxidized pyrite first increased and then decreased.When the content of sodium sulfide is high,the recovery of fine oxidized pyrite is less than 10%,and the separation trend between fine oxidized pyrite and digenite is obvious.When the oxidation time is long,due to the large amount of Fe³⁺produced by the oxidation dissolution of pyrite surface and it is adsorbed on the surface of digenite,so the separation and recovery of the two minerals can not be realized.The Fe³⁺content is low when the oxidation time is short,which has little effect on the agglomeration flotation of digenite,so the efficient separation and recovery of digenite and pyrite can be realized.This study has important guiding significance for the flotation separation of fine oxidized digenite and pyrite.When the content of Fe³⁺produced by pyrite surface oxidation is lower than a certain value,fine digenite can be effectively recovered by sulfur induced agglomeration flotation technology.However,when the Fe³⁺content is higher than a certain value,certain measures must be taken to desorb Fe³⁺from the surface of digenite or reduce the Fe³⁺content in pulp before vulcanization.