Study on the Mechanism and Kinetics of Manganese Release from Waste Manganese Ore Waste Rock Under Rainfall Leaching

Abstract Manganese released from manganese ore wastes under leaching poses a serious threat to the local ecosystem and human health. The mechanism and dynamic characteristics of manganese release under the leaching of manganese ore waste rock are studied based on static and dynamic experiment. The concentration of manganese in the leaching solution under the disturbance state is twice as much as that in the static state; the manganese release from the waste rock increases with the increase of the solid-liquid ratio, and the manganese release is 922.35mg/l when the solid-liquid ratio is 1:5; when the particle size of waste rock is greater than 80 mesh, the precipitation amount of manganese is the largest, and the precipitation concentration is 491.3mg/l; at pH = 7, rainfall intensity is 80 With the increase of leaching time, the amount of manganese released rapidly decreased and gradually reached equilibrium; the cumulative release of manganese increased with the increase of rainfall duration. In the dynamic leaching process, the change of pH and EC of leachate has nothing to do with the initial pH of leachate, but has a close relationship with the hydrolysis of minerals in waste; through the fitting results of kinetic model, it is found that the double constant equation model can better fit the kinetic process of release process. The purpose of this study is to provide a scientific basis for the assessment and control of manganese pollution in soil and groundwater in manganese mining area.