Study on Characteristics of Heavy Metal Pollutants Leaching from Coal Gangue by Simulation Experiment
Taking coal gangue from a mining area in Xinjiang as the research object,dynamic leaching ex-periments were conducted to study the leaching characteristics of Cu,Cd,Cr and Pb in coal gangue.The release patterns of the four elements were analyzed,the pollution level to the environment was evaluated,and the influ-ence of leaching conditions on the release was investigated.The result showed that Cu,Cd,Cr and Pb had the characteristics of high leaching concentration and fast release rate in the early stage of leaching.With the ex-tension of leaching time,the leaching concentration of each element decreased and the release rate slowed down until the leaching concentration tended to be stable and the release amount reached equilibrium in the later stage of leaching.The release amount and leaching rate of each element were Cr>Cu>Pb>Cd and Cd>Cr>Cu>Pb,re-spectively.Except for Cd,the release of other elements increased with the decrease of pH value of leachate and the increase of radox potential.
Heavy metalsDynamic leachingRelease amountPollution indexCoal gangue