In order to effectively separate galena and jamesonite and improve the recovery during the mixing flotation, the interaction mechanisms between the minerals and the collector of diethyl dithiocarbamate (DDTC) were i...In order to effectively separate galena and jamesonite and improve the recovery during the mixing flotation, the interaction mechanisms between the minerals and the collector of diethyl dithiocarbamate (DDTC) were investigated. Single mineral flotation test was organized to research the effect of pulp pH value on the flotation behavior of galena and jamesonite. Electrochemistry property of the interaction of these two minerals with DDTC was investigated by cyclic voltammetry and Tafel tests. Flotation test shows that the recovery of jamesonite in high alkaline pulp is strongly depressed by lime (Ca(OH)2). The cyclic voltammetry and Tafel tests results show that the interaction between galena and DDTC is an electrochemical process. High pH value has little influence on the interaction between galena and DDTC, while it has great effect on jamesonite due to self-oxidation and specific adsorption of OH^- and CaOH^+ on jamesonite surface. Non-electroactive hydroxyl compound and low-electroconductive calcium compounds cover the surface of jamesonite, which impedes electron transfer and DDTC adsorption, thus leads to very low floatability of jamesonite.展开更多
A complex lead-zinc-silver sulfide ore containing 2.98% Pb, 6.49% Zn and 116.32×10^-4 % Ag (mass fraction) from Yunnan Province, China, was subjected to this work. Research on mineral processing was conducted a...A complex lead-zinc-silver sulfide ore containing 2.98% Pb, 6.49% Zn and 116.32×10^-4 % Ag (mass fraction) from Yunnan Province, China, was subjected to this work. Research on mineral processing was conducted according to the properties of the lead-zinc-silver ore. Under low alkalinity condition, the lead minerals are successfully separated from the zinc minerals with new reagent YZN as zinc depressant, new reagent BPB as lead collector, CuSO4 as zinc activator and ethyl xanthate as zinc collector. The associated silver is mostly concentrated to the lead concentrate. With the process utilized in this work, a lead concentrate of 51.90% Pb with a recovery of 82.34% and a zinc concentrate of 56.96% Zn with a recovery of 81.98% are produced. The silver recovery in the lead concentrate is 80.61%. Interactions of flotation reagents with minerals were investigated, of which the results indicate that the presence of proper amount of Na2S can precipitate Pb^2+ and has a sulfidation on oxidized lead minerals. The results also show that NazCO3 and YZN used together as combined depressants for sphalerite can signally improve the depressing effect of new reagent YZN on sphalerite.展开更多
Sodium sulfide leaching of a low-grade jamesonite concentrate in the production of sodium pyroantimoniate through the air oxidation process and the influencing factors on the leaching rate of antimony were investigate...Sodium sulfide leaching of a low-grade jamesonite concentrate in the production of sodium pyroantimoniate through the air oxidation process and the influencing factors on the leaching rate of antimony were investigated. In order to decrease the consumption of sodium sulfide and increase the concentration of antimony in the leaching solution, two-stage leaching of jamesonite concentrate and combination leaching of high-grade stibnite concentrate and jamesonite concentrate were used. The experimental results show that the consumptions of sodium sulfide for the two-stage leaching process and the combination leaching process are decreased by 20% and 60% compared to those of one-stage leaching process respectively. The final concentrations of antimony in the leaching solutions of both processes are above 100g/L.展开更多
In this paper,sulfidation mechanism of cerussite in the presence of sulphur at high temperatures was investigated based on micro-flotation,X-ray powder diffractometry(XRD),electron probe microanalysis(EPMA)and X-ray p...In this paper,sulfidation mechanism of cerussite in the presence of sulphur at high temperatures was investigated based on micro-flotation,X-ray powder diffractometry(XRD),electron probe microanalysis(EPMA)and X-ray photoelectron spectroscopy(XPS).The micro-flotation test results showed that flotation recovery of the treated cerussite increased to above 80%under a suitable flotation condition.It was found that the S/PbCO3 mole ratio and pH obviously affected flotation recovery.XRD analysis results confirmed that the cerussite was decomposed into massicot and then was transformed into mainly PbS and PbO·PbSO4 after sulfidation roasting.EPMA analysis results demonstrated that surface of the obtained massicot was smooth,but surface of the artificial galena was rough and even porous.Content of oxygen decreased,whereas content of sulphur increased with an increase in the S/PbCO3 mole ratio.XPS analysis results revealed that various lead-bearing species,including mainly PbS,PbSO4 and PbO·PbSO4,were generated at the surface.Formation of PbS was advantageous to flotation of the treated cerussite.Based on these results,a reaction model of the cerussite sulfurized with sulphur was proposed.展开更多
The electrochemical mechanism involved in the selective separation of chalcopyrite from galena was investigated by flotation and electrochemical methods in the presence of sodium sulfite and sodium silicate,respective...The electrochemical mechanism involved in the selective separation of chalcopyrite from galena was investigated by flotation and electrochemical methods in the presence of sodium sulfite and sodium silicate,respectively,as a single depressant and their mixture as a combined depressant.Flotation tests revealed that the floatability of chalcopyrite was unaffected by depressants and its recovery remained constant(>80%)within the studied dosage range.Galena flotation was severely depressed with descending depressing order as follows:combined depressant﹥sodium silicate﹥sodium sulfite.Electrochemical analysis confirmed the high affinity of depressants on the galena surface,resulting in the formation of hydrophilic species,such as lead sulfite,lead sulfate,and lead orthosilicate.The oxidation of chalcopyrite surface and depressants did not exhibit any signals;conversely,the self-oxidation of chalcopyrite was depressed.The results of cyclic voltammograms well agreed with flotation results,demonstrating that chalcopyrite primarily reacted with the collector O-isopropyl-N-ethyl thionocarbamate and that galena mostly reacted with depressants.展开更多
Fractions of various heavy metals in a sulfidic minespoil were investigated. Column leaching experimentwas also conducted to simulate 'acid mine drainage' (AMD) from the minespoil. The results show thatleachin...Fractions of various heavy metals in a sulfidic minespoil were investigated. Column leaching experimentwas also conducted to simulate 'acid mine drainage' (AMD) from the minespoil. The results show thatleaching of heavy metals from the minespoil was extremely significant during the initial water flushing.The amounts of heavy metals leached out dramatically reduced after leaching twice. It is worthwhile tonote that in this study, Zn, Mn, Fe, As and Ni in the first leachate exceeded the total amount of eachcorresponding water-extractable (1:5, soil:water) metal contained in the minespoil sample. This appears tosuggest that 1:5 water extraction did not allow accurate estimation of water-leachable concentrations of theabove heavy metals. This work has implications for the management of sulfidic minespoils. Acid drainageof great environmental concerns is likely to occur only during heavy rainfall events after substantial solubleand readily exchangeable acid and metals are accumulated in the minespoils. The slow-reacting fractionsother than water-soluble and readily exchangeable fractions may pose little environmental hazards. This isparticularly true for Pb, As and Ni.展开更多
The newly developed green leaching processes for chromium, lead and gold extraction from ores or concentrates are described. The chromium is extracted from the iron chromite ore with fused sodium hydroxide at 500-550...The newly developed green leaching processes for chromium, lead and gold extraction from ores or concentrates are described. The chromium is extracted from the iron chromite ore with fused sodium hydroxide at 500-550℃ as sodium chromate. The galena in lead sulfide concentrate is converted into lead carbonate in ammonium or sodium carbonate solution at 50-80℃ followed by the separation of lead carbonate formed from the unconverted sulfide ores by flotation. Gold associated with sulfide ore (such as pyrite and chalcopyrite) can be extracted into sodium thiosulfate solution without any pretreatment such as roasting, high pressure aqueous oxidation or bacteria pre-leaching.展开更多
基金Projects(5110417951374247)supported by the National Natural Science Foundation of China
文摘In order to effectively separate galena and jamesonite and improve the recovery during the mixing flotation, the interaction mechanisms between the minerals and the collector of diethyl dithiocarbamate (DDTC) were investigated. Single mineral flotation test was organized to research the effect of pulp pH value on the flotation behavior of galena and jamesonite. Electrochemistry property of the interaction of these two minerals with DDTC was investigated by cyclic voltammetry and Tafel tests. Flotation test shows that the recovery of jamesonite in high alkaline pulp is strongly depressed by lime (Ca(OH)2). The cyclic voltammetry and Tafel tests results show that the interaction between galena and DDTC is an electrochemical process. High pH value has little influence on the interaction between galena and DDTC, while it has great effect on jamesonite due to self-oxidation and specific adsorption of OH^- and CaOH^+ on jamesonite surface. Non-electroactive hydroxyl compound and low-electroconductive calcium compounds cover the surface of jamesonite, which impedes electron transfer and DDTC adsorption, thus leads to very low floatability of jamesonite.
基金Project(50874117) supported by the National Natural Science Foundation of China
文摘A complex lead-zinc-silver sulfide ore containing 2.98% Pb, 6.49% Zn and 116.32×10^-4 % Ag (mass fraction) from Yunnan Province, China, was subjected to this work. Research on mineral processing was conducted according to the properties of the lead-zinc-silver ore. Under low alkalinity condition, the lead minerals are successfully separated from the zinc minerals with new reagent YZN as zinc depressant, new reagent BPB as lead collector, CuSO4 as zinc activator and ethyl xanthate as zinc collector. The associated silver is mostly concentrated to the lead concentrate. With the process utilized in this work, a lead concentrate of 51.90% Pb with a recovery of 82.34% and a zinc concentrate of 56.96% Zn with a recovery of 81.98% are produced. The silver recovery in the lead concentrate is 80.61%. Interactions of flotation reagents with minerals were investigated, of which the results indicate that the presence of proper amount of Na2S can precipitate Pb^2+ and has a sulfidation on oxidized lead minerals. The results also show that NazCO3 and YZN used together as combined depressants for sphalerite can signally improve the depressing effect of new reagent YZN on sphalerite.
文摘Sodium sulfide leaching of a low-grade jamesonite concentrate in the production of sodium pyroantimoniate through the air oxidation process and the influencing factors on the leaching rate of antimony were investigated. In order to decrease the consumption of sodium sulfide and increase the concentration of antimony in the leaching solution, two-stage leaching of jamesonite concentrate and combination leaching of high-grade stibnite concentrate and jamesonite concentrate were used. The experimental results show that the consumptions of sodium sulfide for the two-stage leaching process and the combination leaching process are decreased by 20% and 60% compared to those of one-stage leaching process respectively. The final concentrations of antimony in the leaching solutions of both processes are above 100g/L.
基金Project(51964027)supported by the National Natural Science Foundation of ChinaProject(2017FB084)supported by the Yunnan Province Applied Basic Research Project,ChinaProject(2019J0037)supported by the Education Department of Yunnan Province,China。
文摘In this paper,sulfidation mechanism of cerussite in the presence of sulphur at high temperatures was investigated based on micro-flotation,X-ray powder diffractometry(XRD),electron probe microanalysis(EPMA)and X-ray photoelectron spectroscopy(XPS).The micro-flotation test results showed that flotation recovery of the treated cerussite increased to above 80%under a suitable flotation condition.It was found that the S/PbCO3 mole ratio and pH obviously affected flotation recovery.XRD analysis results confirmed that the cerussite was decomposed into massicot and then was transformed into mainly PbS and PbO·PbSO4 after sulfidation roasting.EPMA analysis results demonstrated that surface of the obtained massicot was smooth,but surface of the artificial galena was rough and even porous.Content of oxygen decreased,whereas content of sulphur increased with an increase in the S/PbCO3 mole ratio.XPS analysis results revealed that various lead-bearing species,including mainly PbS,PbSO4 and PbO·PbSO4,were generated at the surface.Formation of PbS was advantageous to flotation of the treated cerussite.Based on these results,a reaction model of the cerussite sulfurized with sulphur was proposed.
基金Project(51374247)supported by the National Natural Science Foundation of ChinaProject(2015CX005)supported by Innovation Driven Plan of Central South University,China+1 种基金Project(B14034)supported by the National“111”Project,ChinaProject supported by the Open Sharing Fund for Large-scale Instruments and Equipment of Central South University and Collaborative Innovation Center for Clean and Efficient Utilization of Strategic Metal Mineral Resources,China。
文摘The electrochemical mechanism involved in the selective separation of chalcopyrite from galena was investigated by flotation and electrochemical methods in the presence of sodium sulfite and sodium silicate,respectively,as a single depressant and their mixture as a combined depressant.Flotation tests revealed that the floatability of chalcopyrite was unaffected by depressants and its recovery remained constant(>80%)within the studied dosage range.Galena flotation was severely depressed with descending depressing order as follows:combined depressant﹥sodium silicate﹥sodium sulfite.Electrochemical analysis confirmed the high affinity of depressants on the galena surface,resulting in the formation of hydrophilic species,such as lead sulfite,lead sulfate,and lead orthosilicate.The oxidation of chalcopyrite surface and depressants did not exhibit any signals;conversely,the self-oxidation of chalcopyrite was depressed.The results of cyclic voltammograms well agreed with flotation results,demonstrating that chalcopyrite primarily reacted with the collector O-isopropyl-N-ethyl thionocarbamate and that galena mostly reacted with depressants.
基金Project partly supported by an internal grant of Southern Cross University,Australia(Project No.305093).
文摘Fractions of various heavy metals in a sulfidic minespoil were investigated. Column leaching experimentwas also conducted to simulate 'acid mine drainage' (AMD) from the minespoil. The results show thatleaching of heavy metals from the minespoil was extremely significant during the initial water flushing.The amounts of heavy metals leached out dramatically reduced after leaching twice. It is worthwhile tonote that in this study, Zn, Mn, Fe, As and Ni in the first leachate exceeded the total amount of eachcorresponding water-extractable (1:5, soil:water) metal contained in the minespoil sample. This appears tosuggest that 1:5 water extraction did not allow accurate estimation of water-leachable concentrations of theabove heavy metals. This work has implications for the management of sulfidic minespoils. Acid drainageof great environmental concerns is likely to occur only during heavy rainfall events after substantial solubleand readily exchangeable acid and metals are accumulated in the minespoils. The slow-reacting fractionsother than water-soluble and readily exchangeable fractions may pose little environmental hazards. This isparticularly true for Pb, As and Ni.
文摘The newly developed green leaching processes for chromium, lead and gold extraction from ores or concentrates are described. The chromium is extracted from the iron chromite ore with fused sodium hydroxide at 500-550℃ as sodium chromate. The galena in lead sulfide concentrate is converted into lead carbonate in ammonium or sodium carbonate solution at 50-80℃ followed by the separation of lead carbonate formed from the unconverted sulfide ores by flotation. Gold associated with sulfide ore (such as pyrite and chalcopyrite) can be extracted into sodium thiosulfate solution without any pretreatment such as roasting, high pressure aqueous oxidation or bacteria pre-leaching.