The adsorption behaviors and mechanisms of gold from thiosulfate solution on strong-base anion exchange resin were systematically investigated.The comparison experiment of adsorption ability and selectivity for gold s...The adsorption behaviors and mechanisms of gold from thiosulfate solution on strong-base anion exchange resin were systematically investigated.The comparison experiment of adsorption ability and selectivity for gold showed that gel Amberlite IRA-400 resin with Type Ⅰ quaternary ammonium functional group had better adsorption performance.The increases of resin dosage,ammonia concentration and solution pH were favorable to gold adsorption,whereas the rises of cupric and thiosulfate concentrations were disadvantageous to gold loading.Microscopic characterization results indicated that gold was adsorbed in the form of [Au(S_(2)O_(3))_(2)]^(3–) complex anion by exchanging with the counter ion Cl^(–) in the functional group of the resin.Density functional theory calculation result manifested that gold adsorption was mainly depended on the hydrogen bond and van der Waals force generated between O atom in [Au(S_(2)O_(3))_(2)]^(3–) and H atom in the quaternary ammonium functional group of the resin.展开更多
The degradation behavior of ethyl xanthate(EX) salt was the most widely used collector in sulfide mineral flotation and emission of flotation tailings with residual EX was harmful to environment. In this work, hydroge...The degradation behavior of ethyl xanthate(EX) salt was the most widely used collector in sulfide mineral flotation and emission of flotation tailings with residual EX was harmful to environment. In this work, hydrogen peroxide(H2O2) was investigated by UV-visible spectroscopy(UV/Vis) at different p H values from 3 to 12. For p H value from 5 to 12, EX was oxidized into ethyl per xanthate(EPX) by H2O2. Then EPX was further oxidized into thiosulfate(TS) salt rather than ethyl thiocarbonate(ETC) and this step was the reaction-limited step. Then depending on p H values, TS was degraded into sulphate and carbonate salts(p H>7) or elemental sulfur(p H<7). The kinetics data show that the degradation rate of EX increases with increasing the H2O2 concentration and is independent on the p H values. Without H2O2, EX is hydrolyzed to carbon disulfide fast at p H value <3.0, but the reaction of hydrolysis is undetectable at p H value >3.0 during test time.展开更多
基金the financial support from the Natural Science Foundation of Hunan Province, China (No. 2023JJ40723)China Postdoctoral Science Foundation (No. 2022M723549)the National Natural Science Foundation of China (Nos. 52174271, 51504293)。
文摘The adsorption behaviors and mechanisms of gold from thiosulfate solution on strong-base anion exchange resin were systematically investigated.The comparison experiment of adsorption ability and selectivity for gold showed that gel Amberlite IRA-400 resin with Type Ⅰ quaternary ammonium functional group had better adsorption performance.The increases of resin dosage,ammonia concentration and solution pH were favorable to gold adsorption,whereas the rises of cupric and thiosulfate concentrations were disadvantageous to gold loading.Microscopic characterization results indicated that gold was adsorbed in the form of [Au(S_(2)O_(3))_(2)]^(3–) complex anion by exchanging with the counter ion Cl^(–) in the functional group of the resin.Density functional theory calculation result manifested that gold adsorption was mainly depended on the hydrogen bond and van der Waals force generated between O atom in [Au(S_(2)O_(3))_(2)]^(3–) and H atom in the quaternary ammonium functional group of the resin.
基金Project(2013AA064102)supported by the National High Technology Research and Development Program of ChinaProject(B14034)supported by the Program of Introducing Talents of Discipline to Universities,ChinaProject supported by the 2011 Collaborative Innovation Center for Clean and Efficient utilization of Strategic Metal Mineral Resources,China
文摘The degradation behavior of ethyl xanthate(EX) salt was the most widely used collector in sulfide mineral flotation and emission of flotation tailings with residual EX was harmful to environment. In this work, hydrogen peroxide(H2O2) was investigated by UV-visible spectroscopy(UV/Vis) at different p H values from 3 to 12. For p H value from 5 to 12, EX was oxidized into ethyl per xanthate(EPX) by H2O2. Then EPX was further oxidized into thiosulfate(TS) salt rather than ethyl thiocarbonate(ETC) and this step was the reaction-limited step. Then depending on p H values, TS was degraded into sulphate and carbonate salts(p H>7) or elemental sulfur(p H<7). The kinetics data show that the degradation rate of EX increases with increasing the H2O2 concentration and is independent on the p H values. Without H2O2, EX is hydrolyzed to carbon disulfide fast at p H value <3.0, but the reaction of hydrolysis is undetectable at p H value >3.0 during test time.
