Reductive leaching of manganese from low-grade pyrolusite ore in sulfuric acid using pyrolysis-pretreated sawdust as a reductant

Ya-li Feng¹，Shi-yuan Zhang^1,2，Hao-ran Li²

1. School of Civil and Environmental Engineering, University of Science and Technology Beijing2. National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences

摘 要：Manganese（Mn） leaching and recovery from low-grade pyrolusite ore were studied using sulfuric acid（H₂SO₄） as a leachant and pyrolysis-pretreated sawdust as a reductant. The effects of the dosage of pyrolysis-pretreated sawdust to pyrolusite ore, the concentration of sulfuric acid, the liquid/solid ratio, the leaching temperature, and the leaching time on manganese and iron leaching efficiencies were investigated. Analysis of manganese and iron leaching efficiencies revealed that a high manganese leaching efficiency was achieved with low iron extraction. The optimal leaching efficiency was determined to be 20wt% pyrolysis-pretreated sawdust and 3.0 mol/L H₂SO₄ using a liquid/solid ratio of 6.0 mL /g for 90 min at 90°C. Other low-grade pyrolusite ores were tested, and the results showed that they responded well with manganese leaching efficiencies greater than 98%.

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