Experimental research on engineering characteristics of manganese residue
LI Shilong1,2,WEI Zuoan1,2,LU Ting1,2,WANG Wensong1,2,YANG Yonghao1,ZHAO Junkang1,2
(1. State Key Laboratory of Coal Mine Disaster Dynamics and Control,Chongqing University,Chongqing 400044,China;2. School of Resources and Safety,Chongqing University,Chongqing 400044,China)
Abstract:Electrolytic manganese residue,also called manganese slag,is a solid waste produced during the electrolytic manganese process. The engineering mechanical properties of manganese slag have great significance for analyzing the stability of manganese slag dams. Through a large number of indoor tests,the soluble salt components in the manganese slag were determined,and the physical and mechanical properties of the manganese slag before and after desalination were tested. The test results show that the soluble salt contained in the manganese slag is sulfate,and the sulfate content is 10.64%﹣13.98%. Thus,the manganese residue belongs to super-saline soil. Due to the presence of crystal water in sulfate,the recommended drying condition is temperature 55 ℃ and time more than 4 d. The particle size gradation of desalted manganese slag is worse than that of original manganese slag. After the manganese slag is desalted,the liquid-plastic limit,optimal moisture content,permeability coefficient and consolidation coefficient increases. But the maximum dry density and compression modulus decreases. With the increase of dry density and water content,the stress-strain relationship of manganese slag gradually changed from strain hardening type to strain softening type. The peak shear strength decreases with the loss of salt. The values of c and φ increase with the increase of dry density or decrease of water content.