The flotation behavior and adsorption mechanism of novel（1-hydroxy-2-methyl-2-octenyl） phosphonic acid（HEPA） to cassiterite were investigated by micro-flotation tests, zeta potential measurements, FTIR determinati...The flotation behavior and adsorption mechanism of novel（1-hydroxy-2-methyl-2-octenyl） phosphonic acid（HEPA） to cassiterite were investigated by micro-flotation tests, zeta potential measurements, FTIR determination and density functional theory（DFT） calculation. The flotation results demonstrated that HEPA exhibited superior collecting performance compared with styrene phosphonic acid（SPA）. The cassiterite recovery maintained above 90% over a wide pH range of 2-9 with 50 mg/L HEPA. The results of zeta potential measurement and FTIR detection indicated that the adsorption of HEPA onto cassiterite was mainly attributed to the chemisorption between HEPA monoanions and Sn species on mineral surfaces. The DFT calculation results demonstrated that HEPA monoanions owned higher HOMO energy and exhibited a better affinity to cassiterite than SPA, which provided very clear evidence for the stronger collecting power of HEPA presented in floatation test and zeta potential measurement.展开更多
Electronic structures of complex mineral jamesonite were studied using density functional theory method together with their flotation behavior. The flotation behavior ofjamesonite is similar to that of stibnite, indic...Electronic structures of complex mineral jamesonite were studied using density functional theory method together with their flotation behavior. The flotation behavior ofjamesonite is similar to that of stibnite, indicating good floatability at pH below 6 and easy depression with NaOH, especially with lime. In weak alkaline condition, the flotation behavior ofjamesonite is close to that of galena. The coordination structure of Pb for jamesonite is more complex than that for galena. Sb in jamesonite possesses two coordinated modes, whereas Sb of stibnite is only 3-coordinated. Pb in galena is more active than that in jamesonite. Sb （3-coordination） in jamesonite is inactive, in contrast with that in stibnite. However, 4-coordination Sb in jamesonite is more active than 3-coordination Sb. HOMO orbitals of jamesonite and stibnite contain metal atoms, which contribute to the formation of adsorption configuration of CaOH^＋ when there is lime; therefore, jamesonite and stibnite are easily depressed by lime.展开更多
Sodium hexametaphosphate(SHMP)was used to minimize the adverse effect of serpentine for improving aschariterecovery.The effects of particle size and content of SHMP,and serpentine on ascharite flotation process were i...Sodium hexametaphosphate(SHMP)was used to minimize the adverse effect of serpentine for improving aschariterecovery.The effects of particle size and content of SHMP,and serpentine on ascharite flotation process were investigated throughflotation,zeta potential tests,FT-IR analysis,XPS analysis and DLVO theory.Particles interaction and mechanism of SHMP werealso discussed.It was found that aggregation between serpentine and ascharite particles easily happened,and the particle size ofserpentine had a profound impact on the ascharite recovery.In particular,the fine serpentine with size less than38μm had thegreatest contribution to the deterioration of ascharite flotation performance.After SHMP treatment,the adverse effect of serpentinewas significantly reduced.The mechanism of SHMP showed that it could alter the surface charges of serpentine and ascharite toprevent severe interparticle aggregation,which resulted in a well-dispersed pulp and benefited ascharite flotation process.Theadsorption of SHMP on serpentine was due to hydrogen bonding and chemical adsorption,resulting in the formation of complex onserpentine surface to decrease its floatability.展开更多
基金Project(2013AA064102)supported by the 12th Five-year Plan of National Scientific and Technological Program of China
文摘The flotation behavior and adsorption mechanism of novel（1-hydroxy-2-methyl-2-octenyl） phosphonic acid（HEPA） to cassiterite were investigated by micro-flotation tests, zeta potential measurements, FTIR determination and density functional theory（DFT） calculation. The flotation results demonstrated that HEPA exhibited superior collecting performance compared with styrene phosphonic acid（SPA）. The cassiterite recovery maintained above 90% over a wide pH range of 2-9 with 50 mg/L HEPA. The results of zeta potential measurement and FTIR detection indicated that the adsorption of HEPA onto cassiterite was mainly attributed to the chemisorption between HEPA monoanions and Sn species on mineral surfaces. The DFT calculation results demonstrated that HEPA monoanions owned higher HOMO energy and exhibited a better affinity to cassiterite than SPA, which provided very clear evidence for the stronger collecting power of HEPA presented in floatation test and zeta potential measurement.
基金Project(NCET-11-0925)supported by the New Century Excellent Talents in University,ChinaProject(51164001)supported by the National Natural Science Foundation of ChinaProject supported by Open Foundation of Guangxi Key Laboratory for Advanced Materials and Manufacturing Technology,China
文摘Electronic structures of complex mineral jamesonite were studied using density functional theory method together with their flotation behavior. The flotation behavior ofjamesonite is similar to that of stibnite, indicating good floatability at pH below 6 and easy depression with NaOH, especially with lime. In weak alkaline condition, the flotation behavior ofjamesonite is close to that of galena. The coordination structure of Pb for jamesonite is more complex than that for galena. Sb in jamesonite possesses two coordinated modes, whereas Sb of stibnite is only 3-coordinated. Pb in galena is more active than that in jamesonite. Sb （3-coordination） in jamesonite is inactive, in contrast with that in stibnite. However, 4-coordination Sb in jamesonite is more active than 3-coordination Sb. HOMO orbitals of jamesonite and stibnite contain metal atoms, which contribute to the formation of adsorption configuration of CaOH^＋ when there is lime; therefore, jamesonite and stibnite are easily depressed by lime.
基金Project(51204033) supported by the National Natural Science Foundation of ChinaProject(L2014088) supported by Liaoning Provincial Education Department of China
文摘Sodium hexametaphosphate(SHMP)was used to minimize the adverse effect of serpentine for improving aschariterecovery.The effects of particle size and content of SHMP,and serpentine on ascharite flotation process were investigated throughflotation,zeta potential tests,FT-IR analysis,XPS analysis and DLVO theory.Particles interaction and mechanism of SHMP werealso discussed.It was found that aggregation between serpentine and ascharite particles easily happened,and the particle size ofserpentine had a profound impact on the ascharite recovery.In particular,the fine serpentine with size less than38μm had thegreatest contribution to the deterioration of ascharite flotation performance.After SHMP treatment,the adverse effect of serpentinewas significantly reduced.The mechanism of SHMP showed that it could alter the surface charges of serpentine and ascharite toprevent severe interparticle aggregation,which resulted in a well-dispersed pulp and benefited ascharite flotation process.Theadsorption of SHMP on serpentine was due to hydrogen bonding and chemical adsorption,resulting in the formation of complex onserpentine surface to decrease its floatability.
