Key Laboratory of Unconventional Metallurgy, Ministry of Education, Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, Yunnan, PR China.
Key Laboratory of Unconventional Metallurgy, Ministry of Education, Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, Yunnan, PR China; Key Laboratory of Green-Chemistry Materials in University of Yunnan Province, Yunnan Minzu University, Kunming 650500, Yunnan, PR China; Hunan Provincial Key Laboratory of Efficient and Clean Utilization of Manganese Resources, Central South University, Changsha 410083, Hunan, PR China.
Bioresour Technol. 2019 Nov;291:121838. doi: 10.1016/j.biortech.2019.121838. Epub 2019 Jul 19.
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 MnO 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.
利用生物质作为碳源替代化石能源来转化金属氧化物，对于减少矿物质的消耗具有重要意义。本研究提出了利用微波热解核桃壳还原低品位软锰矿的方法。热重分析表明，生物质热解还原软锰矿的过程可分为四个阶段，其特征温度分别为：脱水阶段（<150°C）、预分解阶段（150°C-290°C）、固化分解阶段（290°C-480°C）和碳化阶段（>480°C）。当 18%的核桃壳在 650°C 下加热 30 分钟时，锰的回收率达到 92.01%。此时产物具有最强的 MnO 择优取向，结晶结构良好，未检测到 MnO 和 FeO 峰。产物表面变得疏松多孔，有大量的裂纹、凹坑和孔，熔融颗粒相互连接且堆积成规则的形状。该方法为基于生物质微波加热的选择性还原软锰矿提供了新思路。
