| Copper-nickel sulfide ore has complex property,with uneven disseminated grain size,easily to be oxidized and overcrushed,poor natural floatability,gangue easily been mudded,similar floatability with iron sulfide,additionally,mineral particles are prone to heterogeneous condensation,which leads to poor flotation index of copper-nickel sulfide ores and seriously restricts efficient utilizing copper and nickel resource in China.Pentlandite,chalcopyrite,pyrrhotite and serpentine minerals,existing in copper-nickel sulfide ores,have a relative greater effect on the floatation.And research on the relationship among their crystal structures,surface properties and flotation behaviors as well as impact of floatation agent on aggregation and dispersion behavior of interaction between minerals,contribute to a further understanding of the crystal chemical characteristics,mineral flotation rule and interaction mechanism,and provide a theoretical basis for copper-nickel sulphide flotation.Aimed at pentlandite,chalcopyrite,pyrite,pyrrhotite and serpentine 5 kinds of single mineral,by single mineral flotation,solution chemical calculated and potential test,relationships of mineral crystal structure,surface electrical and natural floatability were researched.And result shows that:point of zero charge of nickel pyrite,chalcopyrite,pyrrhotite,pyrite were 4.8,5.4,2.0,3.8,for serpentine 9.7.Under the condition of copper-nickel sulfide ores flotation at natural pH value,surface of serpentine is positively charged copper-nickel sulfide ore while other minerals are negatively charged.In the flotation system of sodium butyl xanthate,natural floatabilities in copper-nickel sulfide ore,chalcopyrite and pentlandite are stronger,pyrrhotite,and pyrite are weaker;serpentine is poor and non selective.In sodium butyl xanthate system,combined with crystal chemistry and solution flotation chemistry,floatability of each single mineral in copper-nickel sulfide ore and floatation behavior after adding various adjustment agents were studied,floatability effect rules of metal ions and inorganic modifiers on five kinds of single mineral were analysized,the result shows that at different pH values calcium ion has certain depression on pentlandite,pyrite and pyrrhotite.Iron ion has strong depression on pentlandite,chalcopyrite,pyrite,and certain depression on pentlandite. At acidic conditions,and activation on serpentine.Copper ion has obvious activation on pentlandite,pyrrhotite,pyrite and serpentine,which varies based on pH values,but no obvious effect on chalcopyrite.In a wide range of pH,sodium sulfide has strong depression on pentlandite,chalcopyrite,pyrrhotite and serpentine;In acidic and weak alkaline conditions,sodium sulfide has certain depression on pyrite.Sodium carbonate has a strong depression on pyrite and pyrrhotite,and relatively weaker influence on pentlandite,chalcopyrite and serpentine.In a wide pH value range sodium hexametaphosphate and sodium silicate have relatively stronger depression on pentlandite,pyrite,pyrrhotite and serpentine,and depression on chalcopyrite under alkaline conditions.Pentlandite,chalcopyrite and serpentine,as the typical mineral in copper-nickel sulfide ore,were set as the research objects.Through artificial mixed mineral test,Zeta potential test,surface wetting,calculation on energy of inter particle effect and analysis of scanning electron microscope,the interaction of different size fractions of serpentine on copper-nickel sulfide ore was studied,different modifiers on the separation of copper-nickel and serpentine separation effect and serpentine inhibitory mechanism were researched.The results show that in flotation process of copper-nickel sulfide ore,serpentine depressed chalcopyrite and pentlandite,while increasing the MgO content of the concentrate,the more content and finer grain size of serpentine,the greater impact on copper-nickel ore flotation.Phosphate and silicate regulator can both improve the separation effect of chalcopyrite,pentlandite and serpentine,the effect for sodium hexametaphosphate is the best and sodium silica is second,sodium fluorosilicate and sodium phosphate are the worst.Through surface wettability test and zeta potential test,the interaction energy of mineral was calculated.When there is no regulator,their interaction energy of chalcopyrite,pentlandite and serpentine are negative,and there is mutual attraction between particles and thus the particles condense.With the radius of serpentine ore becoming smaller,the mutual attraction is increasing and cohesion was intensified.By adding regulators of sodium hexametaphosphate and sodium silicate.When the PH value is 9,the electrical property of the surface of serpentine transforms from positive to negative,leading the electrical property of chalcopyrite and pentlandite surface to becoming more negative and producing the electrostatic repulsion,the interaction energy is positive and mutual exclusion exists among particles,thus eliminates heterogeneous condensation.Copper-nickel sulfide ores from Yunnan contains valuable minerals includes chalcopyrite,chalcocite,pentlandite,and gangue included serpentine and quartz.According to previous research,the thesis adopted sodium carbonate,copper sulfate and sodium hexametaphosphate as regulators,to regulate pH value,depress pyrite and pyrrhotite,activate pentlandite,increase the total E-DLVO potential between chalcopyrite and pentlandite and serpentine gangue minerals.Through the condition test and the closed-circuit test,the process was determined,namely,two segments roughing,two segments cleaning,and two segments scavenging,with the grind fineness of-0.074mm accounting for 70%,Na2CO3 addition 1000g/t,sodium hexametaphosphate addition 300g/t,CuS04 addition 200g/t,collectors addition 150g/t,2#oil addition 40g/t,and the qualified concentrate indexes were grade of copper and nickel 4.87%and 3.05%,recovery of copper and nickel 84.39%,78.83%,according to closed-circuit test.Taking single mineral tests and mechanism research as the guidance,mineral processing was studied on copper-nickel suifide ore from Jilin,and result shows after adopting fast floatation,one roughing,two segments cleaning,two segments scavenging process,floatation index is grade and recovery of nickel 7.47%and 82.57%,for Cu of 2.19%and 91.73%.By SEM,EDS spectrum and XRD flotation concentrate and tailing were analysized,fine effects of magnesium content reduction and grade promotion of concentrate were achieved with CuSO4 as activator and Na2CO3 and sodium hexametaphosphate as regulators.The research achievements enriches the theoretical system of copper-nickel sulfide ore flotation,and provides new ideas for flotation of refractory copper-nickel sulfide ore and has guiding significance for its practice on the flotation. |
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