摘要
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.
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 H7） or elemental sulfur（p H7）. 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.
基金
Project(2013AA064102)supported by the National High Technology Research and Development Program of China
Project(B14034)supported by the Program of Introducing Talents of Discipline to Universities,China
Project supported by the 2011 Collaborative Innovation Center for Clean and Efficient utilization of Strategic Metal Mineral Resources,China
