A new flowsheet was developed to recover the valuable minerals from oxide or oxide-sulfide ores of lead and zinc. The flowsheet consisted of flotation of sulfide minerals, desliming and sulphidization-flotation of oxi...A new flowsheet was developed to recover the valuable minerals from oxide or oxide-sulfide ores of lead and zinc. The flowsheet consisted of flotation of sulfide minerals, desliming and sulphidization-flotation of oxide minerals. The corresponding reagent system and techniques to the flowsheet were investigated. Batch and continuous tests show that the dosage of sodium sulfide, temperature, and collector type are main affecting factors on the recovery of smithsonite and cerussite. For the flotation of cerussite, there is an appropriate dosage of sodium sulfide at which the recovery reaches its maximum value. The required sodium sulfide for smithsonite flotation is higher than that for cerussite and the recovery of smithsonite flotation increases with the dosage of sodium sulfide at low level and becomes insensitive at high dosage. The appropriate temperature for smithsonite and cerussite flotation is found to be 2540℃. Amines are found to be the effective collectors for the flotation of smithsonite after sulphidization. Investigation also shows that desliming prior to sulphidization-flotation is essential to the effective recovery of smithsonite and cerussite, and the desliming process of two-stage hydrocyclon is well feasible and effective for the treatment of lead-zinc oxide ores. A further treatment on the cerussite flotation concentrate by shaking table is proposed to obtain higher lead grade.展开更多
Leaching of blended slag(BS)was investigated in a microwave oven using hydrogen peroxide and acetic acid.The BSwas a mixture of converter and flash furnace slag containing51%Fe2O3,3.8%CuO,and3.2%ZnO.The important vari...Leaching of blended slag(BS)was investigated in a microwave oven using hydrogen peroxide and acetic acid.The BSwas a mixture of converter and flash furnace slag containing51%Fe2O3,3.8%CuO,and3.2%ZnO.The important variables thatinfluence the metal extraction yield were leaching time,liquid-solid ratio,H2O2and CH3COOH concentrations.The preferredleaching conditions were as follows:CH3COOH concentration4mol/L;H2O2concentration4mol/L;microwave power900W;leaching time30min;liquid-solid ratio25mL/g BS;leaching temperature100°C.Under these conditions,the metal extractions of95%Cu,1.6%Fe,and30%Zn were obtained.The results were compared with the traditional leaching results.It is evident thatmicrowave heating causes a reduction in the leaching time.Also,the extraction yield results indicate that selective leaching of BS canbe achieved under the preferred conditions.The dissolution kinetic of BS in hydrogen peroxide with acetic acid is controlled by ashrinking unreacted core model equation.The apparent activation energy and reaction order were found to be16.64kJ/mol and1.09,respectively.展开更多
The effect of grinding on the spodumene flotation was investigated. The flotation response of spodumene ground by different mills was different, due to the variation of metal ions on spodumene surfaces caused by grind...The effect of grinding on the spodumene flotation was investigated. The flotation response of spodumene ground by different mills was different, due to the variation of metal ions on spodumene surfaces caused by grinding environments and/or impurities. The samples were subjected to acid pickling treatment to remove most of the metal ions from the surfaces, and then all samples showed the same poor flotation response, which confirmed the significance of surface metal ions. Metal ion impurities may come from both grinding environments and lattice substitutions in spodumene. Density functional theory (DFT) calculation revealed that Fe and Ca could exist as lattice substitutions on the spodumene surface while Mg substitution is unlikely to occur. Furthermore, Fe is considered to be active site for the absorption of sodium oleate on the spodumene surface. Morphology analysis showed differences in particle size and shape for samples ground by different mills, resulting in different amounts of exposed surfaces. The particle size, cleavage characteristics caused by grinding environments, and metal ion impurities originated from grinding and isomorphous substitutions, play significant roles in the chemisorption of collector on the spodumene surface.展开更多
文摘A new flowsheet was developed to recover the valuable minerals from oxide or oxide-sulfide ores of lead and zinc. The flowsheet consisted of flotation of sulfide minerals, desliming and sulphidization-flotation of oxide minerals. The corresponding reagent system and techniques to the flowsheet were investigated. Batch and continuous tests show that the dosage of sodium sulfide, temperature, and collector type are main affecting factors on the recovery of smithsonite and cerussite. For the flotation of cerussite, there is an appropriate dosage of sodium sulfide at which the recovery reaches its maximum value. The required sodium sulfide for smithsonite flotation is higher than that for cerussite and the recovery of smithsonite flotation increases with the dosage of sodium sulfide at low level and becomes insensitive at high dosage. The appropriate temperature for smithsonite and cerussite flotation is found to be 2540℃. Amines are found to be the effective collectors for the flotation of smithsonite after sulphidization. Investigation also shows that desliming prior to sulphidization-flotation is essential to the effective recovery of smithsonite and cerussite, and the desliming process of two-stage hydrocyclon is well feasible and effective for the treatment of lead-zinc oxide ores. A further treatment on the cerussite flotation concentrate by shaking table is proposed to obtain higher lead grade.
文摘Leaching of blended slag(BS)was investigated in a microwave oven using hydrogen peroxide and acetic acid.The BSwas a mixture of converter and flash furnace slag containing51%Fe2O3,3.8%CuO,and3.2%ZnO.The important variables thatinfluence the metal extraction yield were leaching time,liquid-solid ratio,H2O2and CH3COOH concentrations.The preferredleaching conditions were as follows:CH3COOH concentration4mol/L;H2O2concentration4mol/L;microwave power900W;leaching time30min;liquid-solid ratio25mL/g BS;leaching temperature100°C.Under these conditions,the metal extractions of95%Cu,1.6%Fe,and30%Zn were obtained.The results were compared with the traditional leaching results.It is evident thatmicrowave heating causes a reduction in the leaching time.Also,the extraction yield results indicate that selective leaching of BS canbe achieved under the preferred conditions.The dissolution kinetic of BS in hydrogen peroxide with acetic acid is controlled by ashrinking unreacted core model equation.The apparent activation energy and reaction order were found to be16.64kJ/mol and1.09,respectively.
基金Project(51674290)supported by the National Natural Science Foundation of ChinaProject(201606370130)supported by the China Scholarship CouncilProject(2016zzts107)supported by the Fundamental Research Funds for the Central Universities of Central South University,China
文摘The effect of grinding on the spodumene flotation was investigated. The flotation response of spodumene ground by different mills was different, due to the variation of metal ions on spodumene surfaces caused by grinding environments and/or impurities. The samples were subjected to acid pickling treatment to remove most of the metal ions from the surfaces, and then all samples showed the same poor flotation response, which confirmed the significance of surface metal ions. Metal ion impurities may come from both grinding environments and lattice substitutions in spodumene. Density functional theory (DFT) calculation revealed that Fe and Ca could exist as lattice substitutions on the spodumene surface while Mg substitution is unlikely to occur. Furthermore, Fe is considered to be active site for the absorption of sodium oleate on the spodumene surface. Morphology analysis showed differences in particle size and shape for samples ground by different mills, resulting in different amounts of exposed surfaces. The particle size, cleavage characteristics caused by grinding environments, and metal ion impurities originated from grinding and isomorphous substitutions, play significant roles in the chemisorption of collector on the spodumene surface.
