Effect of impurities in recycling water on Pb-Ag anode passivation in zinc electrowinning process was investigated by linear scan voltammetry.Results show that passivation process would be affected in the presence of ...Effect of impurities in recycling water on Pb-Ag anode passivation in zinc electrowinning process was investigated by linear scan voltammetry.Results show that passivation process would be affected in the presence of Cl^-and F-in recycling water.It was highly advantageous to take H2SO4 concentration as 180g/L,Mn^2＋ concentration as 3-5 g/L and F-less than 42mg/L.However,passivation process would not be affected when Cl^-concentration was less than 13mg/L without any other ions,or when mass ratio of Mn^2＋ to Cl^-existing in electrolyte was 8,where Cl^-concentration could reach up to 625mg/L.展开更多
In order to break the complex bonds and treat the organic wastewater containing heavy metal,such as Cu-EDTA solution,a novel process of Fe-C micro-electrolysis was proposed.Based on the principle of iron-carbon micro-...In order to break the complex bonds and treat the organic wastewater containing heavy metal,such as Cu-EDTA solution,a novel process of Fe-C micro-electrolysis was proposed.Based on the principle of iron-carbon micro-electrolysis reaction,-OH radicals which were generated under the acidic aerobic condition during the micro-electrolysis process attacked to the organic groups of coordination compounds,which resulted in complex bonds breaking.Therefore copper（Ⅱ） ions were removed via nascent gelatinous ferric hydroxide and ferrous hydroxide,and EDTA was degraded by-OH radicals.Effects of pH value,temperature,electrolysis time and mass ratio of Fe to C on residual concentrations of total organic carbon（TOC） and Cu（Ⅱ） were studied.The mechanism of Fe-C micro-electrolysis was investigated and verified by analyzing micrographs of scanning electron microscopy（SEM）,energy dispersive analysis（EDS） and Fourier transform infrared spectrometry（FTIR）.The removal efficiency is optimal at pH value of 2.0,temperature of 25 °C,the mass ratio Fe to C of 0.02,and reaction time of 60 min.Under above conditions,the concentration of TOC decreases from 200 mg/L to 40.66 mg/L and the residual concentration of Cu（Ⅱ） decreases from initial 60 mg/L to 1.718 mg/L.展开更多
The suspension stage of copper flash smelting was examined by roasting a high arsenic copper smelting feed mixture at 500-900°C for 0-20 s in nitrogen and air atmospheres.The enrichment of copper,lead,zinc,arseni...The suspension stage of copper flash smelting was examined by roasting a high arsenic copper smelting feed mixture at 500-900°C for 0-20 s in nitrogen and air atmospheres.The enrichment of copper,lead,zinc,arsenic,and sulfur in the quenched calcine was determined via chemical analyses.Pyrite and chalcopyrite were the main minerals in the feed mixture,and about 55 wt.%of arsenic was in tennantite.The stability of the feed and the formation of S_(2) and SO_(2)during roasting were surveyed by thermal analysis combined with mass spectrometry.Selected pure impurity sulfides were studied for reference purposes.Results indicated that arsenic was released more easily in inert atmosphere compared to air,in which oxidation products of sulfides captured the released gaseous arsenic.Kinetics analyses showed that the third-order chemical reaction and three-dimensional diffusion models were found as the most suitable mechanism functions of arsenic volatilization in inert and air atmospheres,respectively.展开更多
基金Project(50925417) supported by China National Funds for Distinguished Young ScientistsProject(50830301) supported by the National Natural Science Foundation of China+2 种基金 Project(08JJ3020) supported by the Natural Science Foundation of Hunan Province,ChinaProject(2008SK2007) supported Key Program of Science and Technology of Hunan Province,ChinaPorject(2009ZX07212-001-01) supported by Key Project for Water Pollution Control and Management Technology of China
文摘Effect of impurities in recycling water on Pb-Ag anode passivation in zinc electrowinning process was investigated by linear scan voltammetry.Results show that passivation process would be affected in the presence of Cl^-and F-in recycling water.It was highly advantageous to take H2SO4 concentration as 180g/L,Mn^2＋ concentration as 3-5 g/L and F-less than 42mg/L.However,passivation process would not be affected when Cl^-concentration was less than 13mg/L without any other ions,or when mass ratio of Mn^2＋ to Cl^-existing in electrolyte was 8,where Cl^-concentration could reach up to 625mg/L.
基金Project (50925417) supported by China National Funds for Distinguished Young ScientistsProject (50830301) supported by the National Natural Science Foundation of China+1 种基金Project (2007BAC25B01) supported by the National Key Project of Science and Technical Supporting Programs Funded by Ministry of Science and Technology of China during the 11th Five-year PlanProject (2009ZX07212-001-01) supported by the Major Science and Technology Program for Water Pollution Control and Treatment,China
文摘In order to break the complex bonds and treat the organic wastewater containing heavy metal,such as Cu-EDTA solution,a novel process of Fe-C micro-electrolysis was proposed.Based on the principle of iron-carbon micro-electrolysis reaction,-OH radicals which were generated under the acidic aerobic condition during the micro-electrolysis process attacked to the organic groups of coordination compounds,which resulted in complex bonds breaking.Therefore copper（Ⅱ） ions were removed via nascent gelatinous ferric hydroxide and ferrous hydroxide,and EDTA was degraded by-OH radicals.Effects of pH value,temperature,electrolysis time and mass ratio of Fe to C on residual concentrations of total organic carbon（TOC） and Cu（Ⅱ） were studied.The mechanism of Fe-C micro-electrolysis was investigated and verified by analyzing micrographs of scanning electron microscopy（SEM）,energy dispersive analysis（EDS） and Fourier transform infrared spectrometry（FTIR）.The removal efficiency is optimal at pH value of 2.0,temperature of 25 °C,the mass ratio Fe to C of 0.02,and reaction time of 60 min.Under above conditions,the concentration of TOC decreases from 200 mg/L to 40.66 mg/L and the residual concentration of Cu（Ⅱ） decreases from initial 60 mg/L to 1.718 mg/L.
基金support from the Research Foundation for Doctor of Nanyang Institute of Technology,China(No.NGBJ-2022-27)the National Key Research and Development Program of China(No.2023YFC3904002)+3 种基金the National Natural Science Foundation of China(Nos.52064038,52364056)the Science and Technology Research Project of Henan Province,China(No.252102320113)the Key Scientific Research Project Plan of Colleges and Universities in Henan Province,China(No.25B610009)Jiangxi Provincial Natural Science Foundation,China(Nos.20232BCJ22049,20232ACB214009).
文摘The suspension stage of copper flash smelting was examined by roasting a high arsenic copper smelting feed mixture at 500-900°C for 0-20 s in nitrogen and air atmospheres.The enrichment of copper,lead,zinc,arsenic,and sulfur in the quenched calcine was determined via chemical analyses.Pyrite and chalcopyrite were the main minerals in the feed mixture,and about 55 wt.%of arsenic was in tennantite.The stability of the feed and the formation of S_(2) and SO_(2)during roasting were surveyed by thermal analysis combined with mass spectrometry.Selected pure impurity sulfides were studied for reference purposes.Results indicated that arsenic was released more easily in inert atmosphere compared to air,in which oxidation products of sulfides captured the released gaseous arsenic.Kinetics analyses showed that the third-order chemical reaction and three-dimensional diffusion models were found as the most suitable mechanism functions of arsenic volatilization in inert and air atmospheres,respectively.
