Release Activity and Potential Ecological Risk Assessment of Heavy Metals in Coal Gangue of Hancheng, China

Focused on release activity of different weather degree gangue of Han Cheng, evaluate heavy metals potential release risks by Hakanson instrument. The results showed that the content of heavy metals were more than their background in unweathered gangue. The Sang shuping gangue were Cd，Cr and As, so did Cd, Pb, Cr, Cu, Ni and As in Xia yukou. Residue fraction were the main fraction of heavy metals in gangue. The release potential and activity of heavy metals decreased with the weather degree increasing. The release activity of unweathered and weathered one year of Sang shuping gangue from high to low were Cu, Pb, Ni, Cd, Cr, As and Cd, Pb, Cu, Ni, Cr, As respectively. The release activity of unweathered and weathered one year of Xia yukou gangue from high to low were Cu, Ni, Cr, Pb, Cd, As. The potential ecological risk of heavy metals were in slight degree, and the potential risk index of heavy metals decreased gradually with the increasing of weather degree. The potential risk index of heavy metals from high to low were Cd, Pb, Cu, Ni, As, Cr and Cd, Cu, Pb, Ni, Cr, As respectively.