Effects of bioleaching on the mechanical and chemical properties of waste rocks

Sheng-hua Yin1,2), Ai-xiang Wu1,2), Shao-yong Wang1), and Chun-ming Ai1) 1) Key Laboratory of the Ministry of Education of China for High-Efficient Mining and Safety of Metal Mines, University of Science and Technology Beijing, Beijing 100083, China 2) School of Civil and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China

摘 要：Bioleaching processes cause dramatic changes in the mechanical and chemical properties of waste rocks, and play an important role in metal recovery and dump stability. This study focused on the characteristics of waste rocks subjected to bioleaching. A series of experiments were conducted to investigate the evolution of rock properties during the bioleaching process. Mechanical behaviors of the leached waste rocks, such as failure patterns, normal stress, shear strength, and cohesion were determined through mechanical tests. The results of SEM imaging show considerable differences in the surface morphology of leached rocks located at different parts of the dump. The mineralogical content of the leached rocks reflects the extent of dissolution and precipitation during bioleaching. The dump porosity and rock size change under the effect of dissolution, precipitation, and clay transportation. The particle size of the leached rocks decreased due to the loss of rock integrity and the conversion of dry precipitation into fine particles.

关键词：