Study on Paste Tailings Capping Ecology Reclamation on Acid Mine Waste Rock Dump

摘要

Without adequate soil available, it is difficult to rehabilitate a large area of acid mine waste dump with sustainable plant communities, which has a strong potential acid generation. In the present project, paste tailings capping method has been put forward to reconstruct plant ecosystem on acid mine waste rock dump This rehabilitation method uses paste tailings as capillary break and plant growth media. The tailings used contained 26.3 per cent of particles of less than 20 μm which satisfy the requirement of grain of paste tailings preparation. The tailings are not acid-producing materials. In addition to Cu, total contents of Zn, Pb, Cr, Cd, As and Ni in tailings are lower than those in local soil. Paste tailings concentration 70 per cent ～ 72 per cent was prepared by concentrating ten per cent tailings by using polypropylenecrylic sodium as flocculation. The potential pollution risks are low bv using paste tailings as capillary break layer. Plants directly grown in the tailings did not particularly accumulate Cu, Zn, Pb, Cr, Cd, As, Ni in roots, stem and leaves, which were 0.01 ～ 1.6 times of those grown in soil.