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Depression behaviors of N-thiourea-maleamic acid and its adsorption mechanism on galena in Mo-Pb flotation separation

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International Journal of Mining Science and Technology 2022年第1期32卷 181-189页

作者： Liang Lu Wei Xiong Yangge Zhu Xingrong Zhang Yongxing Zheng State Key Laboratory of Mineral Processing Beijing 102628China BGRIMM Technology Group Beijing 102628China China-South Africa Belt and Road Joint Laboratory on Sustainable Exploration and Utilization of Mineral Resources Beijing 102628China State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Kunming 650093China

In present study,a novel organic depressant N-thiourea-maleamic acid(TMA)was synthesized and applied as a galena depressant in the flotation separation of Mo-Pb ores.The depression behaviors of TMA were tested through flotation experiments.A wider separation window for single minerals over 90.0%was obtained at 30.0 mg/L TMA,confirming that TMA could depress galena significantly,while effected molybdenite floatability slightly.An effective separation was obtained for artificially mixed minerals and actual Mo-Pb ores.The adsorption mechanism on galena was revealed by UV-Vis spectra,zeta potential tests,Fourier transform infrared spectroscopy(FT-IR)analysis,contact angle tests and X-ray photoelectron spectroscopy(XPS)analysis.The zeta potentials of galena became more negative and the contact angle of galena dropped from initial 74.36°to 57.8°with 30.0 mg/L TMA depressant,inferring that TMA had adsorbed on galena surface.The analysis results of UV-Vis spectra,FT-IR and XPS gave further evidence that TMA might chemisorb on galena surface via Pb sites on galena surface and the thiourea group in TMA molecular structure,while the carboxyl group played a role of hydrophilicity.

关键词： Molybdenite galena TMA Separation Adsorption

Separation of galena and chalcopyrite using the difference in their surface acid corrosion characteristics

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International Journal of Minerals,Metallurgy and Materials 2023年第11期30卷 2157-2168页

作者： Haiyun Xie Jialing Chen Pei Zhang Likun Gao Dianwen Liu Luzheng Chen Faculty of Land and Resources Engineering Kunming University of Science and TechnologyKunming 650093China Yunnan Key Laboratory of Green Separation and Enrichment of Strategic Mineral Resources Kunming 650093China

galena(PbS)and chalcopyrite(CuFeS_(2))are sulfide minerals that exhibit good floatability characteristics.Thus,efficiently separating them via common flotation is challenging.Herein,a new method of surface sulfuric acid corrosion in conjunction with flotation separation was proposed,and the efficient separation of galena and chalcopyrite was successfully realized.Contact angle test results showed a substantial decrease in surface contact angle and a selective inhibition of surface floatability for corroded galena.Meanwhile,the contact angle and floatability of corroded chalcopyrite remained almost unaffected.Scanning electron microscope results confirmed that sulfuric acid corrosion led to the formation of a dense oxide layer on the galena surface,whereas the chalcopyrite surface remained unaltered.X-ray photoelectron spectroscopy results showed that the chemical state of S^(2-)on the surface of corroded galena was oxidized to SO_(4)^(2-).A layer of hydrophilic PbSO4was formed on the surface,leading to a sharp decrease in galena floatability.Meanwhile,new hydrophobic CuS_(2),CuS,and Cu_(1-x)Fe_(1-y)S_(2-z)species exhibiting good floatability were generated on the chalcopyrite surface.Finally,theoretical analysis results were further verified by corrosion–flotation separation experiments.The galena–chalcopyrite mixture was completely separated via flotation separation under appropriate corrosion acidity,corrosion temperature,and corrosion time.A novel approach has been outlined in this study,providing potential applications in the efficient separation of refractory copper–lead sulfide ore.

关键词： surface acid corrosion galena chalcopyrite flotation separation efficiency

Flotation behaviors of chalcopyrite and galena using ferrate(Ⅵ) as a depressant

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International Journal of Mining Science and Technology 2023年第1期33卷 93-103页

作者： Yongxing Zheng Yusong Huang Panjin Hu Xianhui Qiu Jinfang Lv Lingyun Bao State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Kunming University of Science and TechnologyKunming 650093China Faculty of Land Resource Engineering Kunming University of Science and TechnologyKunming 650093China Faculty of Resource and Environmental Engineering Jiangxi University of Science and TechnologyGanzhou 341000China

This paper investigated the effects of potassium ferrate(PF)on the flotation performances of chalcopyrite and galena.The flotation results showed that PF obviously depressed galena,but had little effects on the floatability of chalcopyrite within pH range of 4.0–12.0.Zeta potential tests showed that the addition of PF induced the formation of more amounts of hydrophilic species on the surface of galena under an alkaline environment.Industrial grade O-isopropyl-N-ethyl thionocarbamate(IPETC)chemically adsorbed on the surface of the PF-treated chalcopyrite and galena after its addition.Contact angle measurements showed that with the addition of PF,the contact angle of the galena surface significantly decreased compared with the chalcopyrite surface.Localized electrochemical impedance spectroscopy(LEIS)tests showed that the addition of PF increased the impedance of the galena surface.X-ray photoelectron spectroscopy(XPS)analyses revealed that the formation of hydrophilic species,namely lead sulfite,lead hydroxide and ferric hydroxide,on the galena surface,decreased its floatability in the presence of PF,while the formation of hydrophobic species,namely copper disulfide and elemental sulfur,on the chalcopyrite surface,maintained its floatability.Finally,a descriptive model for the reaction of PF with chalcopyrite and galena was proposed.

关键词： Flotation Chalcopyrite galena Potassium ferrate

Kinetics of the electrochemical process of galena electrodes in the diethyldithiocarbamate solution

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International Journal of Minerals,Metallurgy and Materials 2010年第6期17卷 669-674页

作者： Li-li Cheng Ti-chang Sun Xian-ping Luo Dian-zuo Wang School of Civil and Environmental Engineering University of Science and Technology Beijing Beijing 100083 China School of Resources and Environmental Engineering Jiangxi University of Science and Technology Ganzhou 341000 China Chinese Academy of Engineering Beijing 100038 China

The electrochemical process of galena in a pH 12.8 buffer solution was investigated using chronoamperometry and chronopotentiometry. To establish kinetic parameters on the surface of galena in the diethyldithiocarbamate solution, the exchange current density and the dependence of current density on reaction time were determined. Experimental results demonstrate that the exchange current density of galena is 1.585× 10^-2A/m2 in the diethyldithiocarbamate-free solution. In the diethyldithiocarbamate solution, the thickness of lead diethyldi- thiocarbamate adsorbed on the surface of galena is 3.28 molecular layers, the diffusion coefficient of diethyldithiocarbamate on the surface of galena electrodes is 1.13 × 10^-10 m2/s, and the exchange current density of galena is 0.45 A/m2. Lead diethyldithiocarbamate on the surface of galena is firmly adsorbed.

关键词： galena electrochemistry flotation kinetics

Selective depression mechanism of ferric chromium lignin sulfonate for chalcopyrite–galena flotation separation

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International Journal of Minerals,Metallurgy and Materials 2018年第5期25卷 489-497页

作者： Jin-sheng Yu Run-qing Liu Li Wang Wei Sun Hong Peng Yue-hua Hu School of Minerals Processing and Bioengineering Central South University School of Chemical Engineering The University of Queensland

Selective recovery of chalcopyrite–galena ore by flotation remains a challenging issue.The development of highly efficient,low-cost,and environmentally friendly depressants for this flotation is necessary because most of available reagents(e.g.,K_2Cr_2O_4)are expensive and adversely affect the environment.In this study,ferric chromium lignin sulfonate(FCLS),which is a waste-product from the paper and pulp industry,was introduced as a selective depressant for galena with butyl xanthate(BX)as a collector.Results show that the residue recovery of Pb in Cu concentrate was substantially reduced to 4.73%using FCLS compared with 10.71%using the common depressant K_2Cr_2O_4.The underlying mechanisms were revealed using zeta-potential measurements and X-ray photoelectron spectroscopy(XPS).Zeta-potential measurements revealed that FCLS was more efficiently absorbed onto galena than onto chalcopyrite.XPS measurements further suggested that FCLS enhanced the surface oxidation of galena but prevented that of chalcopyrite.Thus,FCLS could be a potential candidate as a depressant for chalcopyrite–galena flotation because of its low cost and its lack of detrimental effects on the environment.

关键词： chalcopyrite galena depressant flotation separation

Bio-oxidation of galena particles by Acidithiobacillus ferrooxidans

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Particuology 2008年第2期6卷 99-105页

作者： Lei Jiang Huaiyang Zhou Xiaotong Peng Zhonghao Ding Wuhan University of Science & Engineering Wuhan 430073 China Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China

This paper deals with the bio-oxidation of galena particles （-80 meshes） using Acidithiobacillus ferrooxidans and compares it with Fe^3＋ oxidation. Experimental results show that, at least, 0.00197 mol galena was leached from lOOmL pulp （density of 3.8%） with 39 days＇ bio-oxidation, as compared to 0.00329 mol galena by Fe^3＋ with 9 days＇ oxidation. Because Fe^3＋ was constantly consumed, leaching by Fe^3＋ almost stopped after 9 days. Large amounts of lead sulfate were detected in both bio-oxidation and Fe^3＋ oxidation of galena. A. ferrooxidans followed a unique growth pattern during the bio-oxidation of galena. In the initial 15 days, the bacteria attached themselves to the galena surface with the formation of erosion pits similar in shape and length to those of the bacteria, and there were hardly any bacteria suspended in the solution. After 15 days, suspended bacteria increased. It is thus suggested that A. ferrooxidans may directly oxidize galena.

关键词： Acidithiobacillus ferrooxidans galena Bio-oxidation

Seaweed glue as a novel polymer depressant for the selective separation of chalcopyrite and galena

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International Journal of Minerals,Metallurgy and Materials 2019年第12期26卷 1495-1503页

作者： Xiong Chen Guo-hua Gu Zhi-xiang Chen School of Minerals Processing and Bioengineering Central South University

The use of seaweed glue(SEG)as a novel polymer depressant for the separation of chalcopyrite from galena with butyl xanthate(BX)as a collector was studied through microflotation experiments.Contact angle,adsorption,dynamic potential,and infrared spectral analyses were conducted to clarify the mechanism underlying the action of SEG on minerals.The results of microflotation experiments indicated that chalcopyrite could be selectively separated from galena by using a SEG depressant concentration of 15 mg·L^-1,BX concentration of 10 mg·L^-1,and methyl isobutyl carbinol concentration of 8.5 mg·L^-1 at pH 8.0.A Cu concentrate with a grading of 23.68wt% was obtained at a recovery rate of 81.52% from mixed minerals with 8.29wt% Cu content.Contact angle analysis showed that the effect of SEG on the wettability of galena was stronger than that on the wettability of chalcopyrite.Adsorption,zeta potential,and FT-IR spectral analyses revealed that SEG and BX were coadsorbed on the surfaces of galena.SEG depressed galena by covering xanthate ions in the functional groups of-COO and mainly underwent weak physisorption on chalcopyrite.These mechanisms account for the ability of SEG to depress galena effectively while enabling chalcopyrite flotation.

关键词： seaweed glue chalcopyrite galena flotation separation

Thermodynamics and density functional theory study of potassium dichromate interaction with galena

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International Journal of Minerals,Metallurgy and Materials 2014年第10期21卷 947-954页

作者： Jian-Hua Chen Xian-Hao Long Li-Hong Lan Qian He College of Chemistry and Chemical Engineering Guangxi University College of Resources and Metallurgy Guangxi University Key Laboratory of Chemical and Biological Transformation Process of Guangxi Higher Education Institutes School of Chemistry and Chemical Engineering Guangxi University for Nationalities

The adsorption heat and reaction rate constant of potassium dichromate on the surface of galena were studied. The results indicate that potassium dichromate tends to adsorption on the galena surface. The reaction order is only 0.08385, suggesting that the concentration of potassium dichromate has little influence on its adsorption on the galena surface. In addition, the simulation of CrO2 4- adsorption on the PbS （100） surface in the absence and presence of O2 was carried out by density functional theory （DFT）. The calculated results show that CrO2 4- species adsorb energetically at the Pb-S bond site, and the presence of O2 can enhance this adsorption.

关键词： flotation potassium dichromate galena adsorption thermodynamics density functional theory

Comparative analysis of the dissolution kinetics of galena in binary solutions of HCl/FeCl_3 and HCl/H_2O_2

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International Journal of Minerals,Metallurgy and Materials 2011年第1期18卷 9-17页

作者： Alafara A.Baba Folahan A.Adekola Department of Chemistry University of Ilorin

A comparative study of the dissolution kinetics of galena ore in binary solutions of FeCl3/HCl and H2O2/HCl has been undertaken.The dissolution kinetics of the galena was found to depend on leachant concentration,reaction temperature,stirring speed,solid-to-liquid ratio,and particle diameter.The dissolution rate of galena ore increases with the increase of leachant concentration,reaction temperature,and stirring speed,while it decreases with the increase of solid-to-liquid ratio and particle diameter.The activation energy （Ea） of 26.5 kJ/mol was obtained for galena ore dissolution in 0.3 M FeCl3 /8.06 M HCl,and it suggests the surface diffusion model for the leaching reaction,while the Ea value of 40.6 kJ/mol was obtained for its dissolution in 8.06 M H2O2 /8.06 M HCl,which suggests the surface chemical reaction model for the leaching reaction.Furthermore,the linear relationship between rate constants and the reciprocal of particle radius supports the fact that dissolution is controlled by the surface reaction in the two cases.Finally,the rate of reaction based on the reaction-controlled process has been described by a semiempirical mathematical model.The Arrhenius and reaction constants of 11.023 s^-1,1.25×10^-4 and 3.65×10^2 s^-1,8.02×10^ 6 were calculated for the 0.3 M FeCl3/8.06 M HCl and 8.06 M H2O2/8.06 M HCl binary solutions,respectively.

关键词： galena hydrochloric acid chloride compounds hydrogen peroxide dissolution leaching