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Updated: Jan 21, 2026

Preparation of Biomass-based Mesoporous Carbon with Higher Nitrogen-/Oxygen-chelating Adsorption for CuII Through Microwave Pre-Pyrolysis
Published on: February 12, 2019
Microwave pyrolysis of walnut shell for reduction process of low-grade pyrolusite
Kangqiang Li1, Guo Chen2, Jin Chen1
1Key Laboratory of Unconventional Metallurgy, Ministry of Education, Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, Yunnan, PR China.
Abstract:
Replacing fossil energy by utilizing biomass as carbon source to convert metal oxides has meaning for reduction of minerals. Microwave pyrolysis of walnut shell for reduction process of low-grade pyrolusite was proposed. Thermogravimetric analysis indicated biomass pyrolysis process for reduction of pyrolusite was divided into four phases identified by temperatures: dehydration stage (<150 °C), pre-pyrolysis stage (150 °C-290 °C), curing decomposition stage (290 °C-480 °C) and carbonization stage (>480 °C), and manganese recovery reached 92.01% at 650 °C for 30 min with 18% walnut shell. The strongest preferential orientation of MnO was appeared, with good crystalline structure and no MnO2 and FeO peaks detected. The product surface became loose and porous with numerous cracks, pits and holes, and molten granules were interconnected and stacked with regular shape. The methods propose new idea of selective reduction of pyrolusite based on biomass pyrolysis by microwave heating.
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