Mineral Phase Reconstruction Coupled with Biomass for the Preparation of Red Mud-Manganese Slag-Based Soil-Like Functional Materials

Harmless treatment and resource recovery are critical for addressing the dual challenges of environmental impact and resource utilization associated with industrial solid wastes.A mineral reconfiguration-based strategy was developed to transform red mud and electrolytic manganese slag into a soil-like functional material.The synergistic stabilization of As,Cd,Cr,Pb,and Mn was achieved through co-processing the solid wastes with biomass-derived stabilizing agents.This treatment significantly reduced the bioavailable Mn concentration in the manganese slag from 8 534.98mg·kg^-1 to 49.22mg·kg^-1 within seven days,achieving a stabilization efficiency of 99.4%.Long-term leaching tests conducted under simulated acid rain (pH 6.00) over a 90-days period demonstrated excellent stability,with leached concentrations of heavy metals-except Mn-remaining consistently below the regulatory thresholds stipulated in China’s Integrated Wastewater Discharge Standard.After 60 days of leaching,the manganese concentration complied with the Class I discharge limit(<2mg·L^-1).The successful cultivation of Pennisetum purpureum and Arundo donax in the treated materials confirmed their soil-like functionality,demonstrating the feasibility of the proposed strategy for the harmless disposal and ecological reuse of industrial solid wastes.