Gypsum sludge,a hazardous waste generated by the non-ferrous smelting industry,presents a significant challenge for disposal and utilization.To investigate the feasibility of substituting gypsum sludge for limestone a...Gypsum sludge,a hazardous waste generated by the non-ferrous smelting industry,presents a significant challenge for disposal and utilization.To investigate the feasibility of substituting gypsum sludge for limestone as a flux for smelting,the effects of calcium sulfate(CaSO_(4))and smelting conditions on oxygen-rich smelting of lead concentrate were studied.The interaction between CaSO_(4)and sulfides facilitates the conversion of CaSO_(4)into CaO,which is crucial for slag formation.The order of the influence of sulfide minerals on the conversion of CaSO_(4)is pyrite>sphalerite>galena.When using gypsum sludge exclusively as the calcium source,under optimal conditions with a CaO/SiO_(2)mass ratio of 0.8,an FeO/SiO_(2)mass ratio of 1.2,a melting temperature of 1150℃,an oxygen flow rate of 1.3 L/min,the recovery rates of Pb and Zn in the lead-rich slag reached 85.01%and 95.69%,respectively,with a sulfur content of 2.65 wt%.The As content in the smelting slag obtained by reduction smelting was 0.02 wt%.Resource utilization of gypsum sludge in lead smelting is a feasible method.展开更多
Water leaching of As2O3 from metallurgical dust containing various metals was investigated,serving the purpose of dearsenization and simultaneous metal enrichment especially for indium.Effects of leaching temperature,...Water leaching of As2O3 from metallurgical dust containing various metals was investigated,serving the purpose of dearsenization and simultaneous metal enrichment especially for indium.Effects of leaching temperature,liquid/solid ratio(LSR)and leaching time were studied.It was found that the initial dissolution was very fast but was then so inhibited by the increasingly dissolved As2O3,which makes it difficult to saturate enough arsenic in the leaching solution or in leaching out all the soluble arsenic with excess dosage of water within acceptable time(120 min).Only about 73%of As2O3 was extracted under the optimal conditions investigated.Two-step leaching showed similar trends and was thus unnecessary for improving As2O3 extraction.These observations could reasonably be accounted for the reversibility of the dissolution reaction.Kinetically,the leaching was described satisfactorily by the semi-empirical Avrami model with the apparent activation energy of 36.08 kJ/mol.The purity of the obtained product As2O3 could reach 98.7%,while the indium could be enriched in the leaching residue without loss.展开更多
The composition of a collector directly affects its collecting performance in mineral flotation.In this study,three vegetable oils were used as the collectors,the flotation performance of scheelite and the differentia...The composition of a collector directly affects its collecting performance in mineral flotation.In this study,three vegetable oils were used as the collectors,the flotation performance of scheelite and the differential analysis were studied through flotation experiments,zeta potential,contact angle measurement and Fourier transform infrared spectrum(FTIR)analysis.Flotation results show that the recovery of scheelite increases in the order of oleic acid<rapeseed oil<rice bran oil<soybean oil,especially in the pH range of 5-8.The distinction in the scheelite recovery is due to the different compositions of these collectors.The addition of LA,LNA and PA(<5%)can increase the recovery of scheelite with OA,but the addition of SA deteriorates the scheelite flotation.Results of zeta potential,contact angle measurement and FTIR analysis indicate that the collector adsorption on scheelite surface is enhanced when using the three vegetable oils.For the raw ore with 0.086%WO3,a rough concentrate containing 1.423%WO3 with the recovery of 84.22%is obtained using soybean oil as the collector.展开更多
Many researchers found that the Fe2+together with less amount of Cu2+can accelerate the leaching of chalcopyrite.In this work,the leaching of chalcopyrite with Cu2+was investigated.The leaching residuals were examined...Many researchers found that the Fe2+together with less amount of Cu2+can accelerate the leaching of chalcopyrite.In this work,the leaching of chalcopyrite with Cu2+was investigated.The leaching residuals were examined by Raman spectroscopy.Based on the leaching experiments,the chemical equilibrium in solution was calculated using Visual MINTEQ.The results showed that the Fe in chalcopyrite lattice was replaced by Cu2+;therefore,the chalcopyrite transformed into covellite.Furthermore,the formation of chalcocite occurred when Fe2+and Fe3+were added to the solution containing Cu2+.The copper extraction increased with a decrease of the initial redox potential(or the ratio of Fe3+/Fe2+).展开更多
Bioleaching is regarded as an essential technology to treat low grade minerals,with the distinctive superiorities of lower-cost and environment-friendly compared with traditional pyrometallurgy method.However,the biol...Bioleaching is regarded as an essential technology to treat low grade minerals,with the distinctive superiorities of lower-cost and environment-friendly compared with traditional pyrometallurgy method.However,the bioleaching efficiency is unsatisfactory owing to the passivation film formed on the minerals surface.It is of particular interest to know the dissolution and passivation mechanism of sulfide minerals in the presence of microorganism.Although bioleaching can be useful in extracting metals,it is a double-edged sword.Metallurgical activities have caused serious environmental problems such as acid mine drainage(AMD).The understanding of some common sulfide minerals bioleaching processes and protection of AMD environment is reviewed in this article.展开更多
Bioleaching experiments combined with X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD)and scanning electron microscopy(SEM)were conducted to investigate three kinds of bornites from different regions leach...Bioleaching experiments combined with X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD)and scanning electron microscopy(SEM)were conducted to investigate three kinds of bornites from different regions leached by moderately thermophilic mixed bacteria of Leptospirillum ferriphilum YSK,Acidithiobacillus caldus D1 and Sulfobacillus thermosulfidooxidans ST.The results of bioleaching experiments showed that the leaching efficiency and the redox potential were significantly increased.The copper extraction efficiencies of three kinds of bornite maintained rapid growth until around the 12th day and no longer increased after the 18th,reaching 83.7%,96.5%and 86.6%,respectively.The XRD results of the leaching residue indicated that three kinds of bornites all produced jarosite in the late stage of leaching,and the leaching residues from of Daye Museum and Yunnan Geological Museum contained a mass of elemental sulfur.XPS analysis and scanning electron microscopy experiments showed that the surface of mineral particles was jarosite and the copper in the leaching residue was almost dissolved.展开更多
In this study,a roasting enhanced flotation process was proposed to recover LiMn_(2)O_(4) and grapite from waste lithium-ion batteries(LIBs).The effects of roasting temperature and time on the surface modification was...In this study,a roasting enhanced flotation process was proposed to recover LiMn_(2)O_(4) and grapite from waste lithium-ion batteries(LIBs).The effects of roasting temperature and time on the surface modification was investigated,and a series of analytical technologies were used to reveal process mechanism.The results indicate that LiMn_(2)O_(4) can be effectively separated from graphite via flotation after the roasting.The flotation grade of LiMn_(2)O_(4) was significantly increased from 63.10%to 91.36%after roasting at 550℃for 2 h.The TG-DTG analysis demonstrates that the difficulty in flotation separation of LiMn_(2)O_(4) from graphite is caused by the organic binder and electrolytes coating on their surfaces.The XRD,SEM,XPS,and contact angle analyses confirm that the organic films on the surfaces of those materials can be effectively removed by roasting,after which the wettability of LiMn_(2)O_(4) is regained and thus the surface wettability difference between the cathode and anode materials is increased significantly.The closed-circuit flotation test indicates that a LiMn_(2)O_(4) sample with high grade of 99.81%is obtained,while the recovery of LiMn_(2)O_(4) is as high as 99.40%.This study provides an economical and eco-friendly way to recycling waste LIBs.展开更多
基金Project(2020YFC1909203)supported by the National Key R&D Project of ChinaProjects(51974364,52074355,51904339)supported by the National Natural Science Foundation of China。
文摘Gypsum sludge,a hazardous waste generated by the non-ferrous smelting industry,presents a significant challenge for disposal and utilization.To investigate the feasibility of substituting gypsum sludge for limestone as a flux for smelting,the effects of calcium sulfate(CaSO_(4))and smelting conditions on oxygen-rich smelting of lead concentrate were studied.The interaction between CaSO_(4)and sulfides facilitates the conversion of CaSO_(4)into CaO,which is crucial for slag formation.The order of the influence of sulfide minerals on the conversion of CaSO_(4)is pyrite>sphalerite>galena.When using gypsum sludge exclusively as the calcium source,under optimal conditions with a CaO/SiO_(2)mass ratio of 0.8,an FeO/SiO_(2)mass ratio of 1.2,a melting temperature of 1150℃,an oxygen flow rate of 1.3 L/min,the recovery rates of Pb and Zn in the lead-rich slag reached 85.01%and 95.69%,respectively,with a sulfur content of 2.65 wt%.The As content in the smelting slag obtained by reduction smelting was 0.02 wt%.Resource utilization of gypsum sludge in lead smelting is a feasible method.
基金Projects(52374293,52174269)supported by the National Natural Science Foundation of ChinaProjects(2022RC1123,2022GK4058)supported by the Science and Technology Innovation Program of Hunan Province,ChinaProject(2021JJ20062)supported by the Natural Science Foundation of Hunan Province,China。
基金Project(51874356)supported by the National Natural Science Foundation of China
文摘Water leaching of As2O3 from metallurgical dust containing various metals was investigated,serving the purpose of dearsenization and simultaneous metal enrichment especially for indium.Effects of leaching temperature,liquid/solid ratio(LSR)and leaching time were studied.It was found that the initial dissolution was very fast but was then so inhibited by the increasingly dissolved As2O3,which makes it difficult to saturate enough arsenic in the leaching solution or in leaching out all the soluble arsenic with excess dosage of water within acceptable time(120 min).Only about 73%of As2O3 was extracted under the optimal conditions investigated.Two-step leaching showed similar trends and was thus unnecessary for improving As2O3 extraction.These observations could reasonably be accounted for the reversibility of the dissolution reaction.Kinetically,the leaching was described satisfactorily by the semi-empirical Avrami model with the apparent activation energy of 36.08 kJ/mol.The purity of the obtained product As2O3 could reach 98.7%,while the indium could be enriched in the leaching residue without loss.
基金Project(2016RS2016) supported by Provincial Science and Technology Leader Program,Hunan,ChinaProject(2017zzts807) supported by Postgraduate Innovative Research Projects of Central South University,China
文摘The composition of a collector directly affects its collecting performance in mineral flotation.In this study,three vegetable oils were used as the collectors,the flotation performance of scheelite and the differential analysis were studied through flotation experiments,zeta potential,contact angle measurement and Fourier transform infrared spectrum(FTIR)analysis.Flotation results show that the recovery of scheelite increases in the order of oleic acid<rapeseed oil<rice bran oil<soybean oil,especially in the pH range of 5-8.The distinction in the scheelite recovery is due to the different compositions of these collectors.The addition of LA,LNA and PA(<5%)can increase the recovery of scheelite with OA,but the addition of SA deteriorates the scheelite flotation.Results of zeta potential,contact angle measurement and FTIR analysis indicate that the collector adsorption on scheelite surface is enhanced when using the three vegetable oils.For the raw ore with 0.086%WO3,a rough concentrate containing 1.423%WO3 with the recovery of 84.22%is obtained using soybean oil as the collector.
基金Project(2016RS2016)supported by the Hunan Provincial Science and Technology Leader(Innovation Team of Interface Chemistry of Efficient and Clean Utilization of Complex Mineral Resources),ChinaProject supported by the Co-Innovation Centre for Clean and Efficient Utilization of Strategic Metal Mineral Resources,ChinaProject(2015CX005)supported by the Innovation Driven Plan of Central South University,China
文摘Many researchers found that the Fe2+together with less amount of Cu2+can accelerate the leaching of chalcopyrite.In this work,the leaching of chalcopyrite with Cu2+was investigated.The leaching residuals were examined by Raman spectroscopy.Based on the leaching experiments,the chemical equilibrium in solution was calculated using Visual MINTEQ.The results showed that the Fe in chalcopyrite lattice was replaced by Cu2+;therefore,the chalcopyrite transformed into covellite.Furthermore,the formation of chalcocite occurred when Fe2+and Fe3+were added to the solution containing Cu2+.The copper extraction increased with a decrease of the initial redox potential(or the ratio of Fe3+/Fe2+).
文摘Bioleaching is regarded as an essential technology to treat low grade minerals,with the distinctive superiorities of lower-cost and environment-friendly compared with traditional pyrometallurgy method.However,the bioleaching efficiency is unsatisfactory owing to the passivation film formed on the minerals surface.It is of particular interest to know the dissolution and passivation mechanism of sulfide minerals in the presence of microorganism.Although bioleaching can be useful in extracting metals,it is a double-edged sword.Metallurgical activities have caused serious environmental problems such as acid mine drainage(AMD).The understanding of some common sulfide minerals bioleaching processes and protection of AMD environment is reviewed in this article.
基金Project(51974363)supported by the National Natural Science Foundation of China。
文摘Bioleaching experiments combined with X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD)and scanning electron microscopy(SEM)were conducted to investigate three kinds of bornites from different regions leached by moderately thermophilic mixed bacteria of Leptospirillum ferriphilum YSK,Acidithiobacillus caldus D1 and Sulfobacillus thermosulfidooxidans ST.The results of bioleaching experiments showed that the leaching efficiency and the redox potential were significantly increased.The copper extraction efficiencies of three kinds of bornite maintained rapid growth until around the 12th day and no longer increased after the 18th,reaching 83.7%,96.5%and 86.6%,respectively.The XRD results of the leaching residue indicated that three kinds of bornites all produced jarosite in the late stage of leaching,and the leaching residues from of Daye Museum and Yunnan Geological Museum contained a mass of elemental sulfur.XPS analysis and scanning electron microscopy experiments showed that the surface of mineral particles was jarosite and the copper in the leaching residue was almost dissolved.
基金Project(2021JJ20062) supported by the Natural Science Foundation of Hunan Province,ChinaProject(2019XK2304) supported by Landmark Innovation Demonstration Project of Hunan Province,China+3 种基金Project(2022GK4058) supported by High-tech Industry Science and Technology Innovation Leading Project of Hunan Province,ChinaProject(2020CX038) supported by the Innovation Driven Project of Central South University,ChinaProject(2019YFC1907301) supported by the National Key R&D Program of ChinaProject(202006375018) supported by the China Scholarship Council。
文摘In this study,a roasting enhanced flotation process was proposed to recover LiMn_(2)O_(4) and grapite from waste lithium-ion batteries(LIBs).The effects of roasting temperature and time on the surface modification was investigated,and a series of analytical technologies were used to reveal process mechanism.The results indicate that LiMn_(2)O_(4) can be effectively separated from graphite via flotation after the roasting.The flotation grade of LiMn_(2)O_(4) was significantly increased from 63.10%to 91.36%after roasting at 550℃for 2 h.The TG-DTG analysis demonstrates that the difficulty in flotation separation of LiMn_(2)O_(4) from graphite is caused by the organic binder and electrolytes coating on their surfaces.The XRD,SEM,XPS,and contact angle analyses confirm that the organic films on the surfaces of those materials can be effectively removed by roasting,after which the wettability of LiMn_(2)O_(4) is regained and thus the surface wettability difference between the cathode and anode materials is increased significantly.The closed-circuit flotation test indicates that a LiMn_(2)O_(4) sample with high grade of 99.81%is obtained,while the recovery of LiMn_(2)O_(4) is as high as 99.40%.This study provides an economical and eco-friendly way to recycling waste LIBs.
