Work

High-efficiency and green recycling of manganese, nickel, cobalt, and zinc in a hydrogen peroxide–sulfuric acid system from electrolytic manganese dioxide sulfide slag

Year: 2025

Type: article

Abstract: Electrolytic manganese dioxide sulfidation slag (EMDSS) is a hazardous waste generated during the production of electrolytic manganese dioxide (EMD), containing strategic metal resources such as nickel (Ni), cobalt (Co), and manganese (Mn), with a total content exceeding 10.00 %. Currently, the recovery of strategic metals from EMDSS has received limited attention, and existing methods are inefficient, accompanied by the risk of H 2 S gas generation. This study proposes a hydrogen peroxide-sulfuric acid (H 2 O 2 -H 2 SO 4 ) leaching process to address these challenges and recover strategic metals such as Mn, Ni, Co, and zinc (Zn) from EMDSS. Optimal process parameters were determined through single-factor and response surface optimization experiments. Thermodynamic, kinetic, and characterization analyses were conducted to elucidate the reaction process and mechanism of H 2 O 2 -H 2 SO 4 leaching. In an acidic environment, sulfide ion (S 2− ) and oxygen ion (O − ) exhibit strong redox reactivity, directly converting into sulfate ion (SO 4 2− ) without generating hydrogen sulfide (H 2 S) gas. The 20 × magnified experiments demonstrated that the average leaching rates of Mn, Ni, Co, and Zn exceeded 99.20 %, with deviations between the measured and predicted values within 1.00 %. The proposed new process achieves over 99.00 % recovery of strategic metals such as Ni, Co, Mn, and Zn, providing raw materials for the subsequent resource utilization of strategic metals. Moreover, stable large-scale experimental results indicate its potential for industrial-scale application, expanding the raw material sources for Ni, Co, and Mn new energy metals.

Source: Resources Environment and Sustainability

DOI: 10.1016/j.resenv.2025.100278