Chang Hao-Hsun, Chen In-Gann, Yu Hao-Yun, Tsai Meng-Yu, Wu Keng-Tung, Liu Shih-Hsien
Department of Materials Science and Engineering, National Cheng Kung University, Tainan 701, Taiwan.
Department of Forestry, National Chung Hsing University, Taichung 402, Taiwan.
Materials (Basel). 2022 Apr 3;15(7):2639. doi: 10.3390/ma15072639.
With recent increases in environmental awareness, the circular economy concept, which involves turning waste into usable products, has gradually become widely accepted. Spent mushroom substrate (SMS) is an agricultural waste that lacks recycling channels in Taiwan. This study explored the feasibility of simultaneously recycling two completely different types of waste: spent mushroom substrate (SMS), an agricultural waste, and electric-arc furnace dust (EAFD), an industrial waste. Specifically, SMS was used to replace metallurgical coke as a reducing agent for EAFD, which underwent carbothermic reduction to recycle valuable metallic Zn. The results showed that if SMS and EAFD were mixed at a C/O ratio of 0.8, the degree of Zn removal achieved 95% at 1100 °C, which is 150 °C lower than the reduction temperature of the EAFD-coke mixture (due to volatile matter (VM) in SMS). For the reduction of ZnO in EAFD, with the assistance of VM in SMS, the C/O ratio can be decreased from 0.8 to 0.16 at 1300 °C, achieving a high degree of Zn removal over 95%. In addition, the torrefaction of SMS increased the fixed carbon content and improved the Zn productivity at the same C/O ratio, reaching almost the same productivity as the coke sample (SMS torrefaction = 500 °C, C/O = 0.8, reduction = 1200 °C, Zn removal~99%). Finally, CO emission reductions from the use of SMS were also estimated.
随着近期环境意识的提高，涉及将废物转化为可用产品的循环经济概念已逐渐被广泛接受。废蘑菇渣（SMS）是台湾一种缺乏回收渠道的农业废弃物。本研究探讨了同时回收两种完全不同类型废物的可行性：农业废弃物废蘑菇渣（SMS）和工业废弃物电弧炉粉尘（EAFD）。具体而言，使用SMS替代冶金焦作为EAFD的还原剂，EAFD经过碳热还原以回收有价值的金属锌。结果表明，如果SMS和EAFD以C/O比为0.8混合，在1100℃时锌的去除率达到95%，这比EAFD - 焦炭混合物的还原温度低150℃（由于SMS中的挥发性物质（VM））。对于EAFD中ZnO的还原，在SMS中VM的辅助下，在1300℃时C/O比可从0.8降至0.16，实现超过95%的高锌去除率。此外，SMS的烘焙增加了固定碳含量，并在相同C/O比下提高了锌生产率，达到与焦炭样品几乎相同的生产率（SMS烘焙 = 500℃，C/O = 0.8，还原 = 1200℃，锌去除率~99%）。最后，还估算了使用SMS带来的CO减排量。
