Abstract: The pyrometallurgy combined with hydrometallurgy process is commonly used for recovering valuable elements from spent lithium-ion batteries.To improve the corrosion resistance of heat treatment furnace lining materials in this process,SiC-Si₃N₄-C composite refractories were prepared by heat-treating at 800-1 400 ℃ for 3 h,using fine particles of used iron ladle bricks (1-0.5 and <0.5 mm),silicon carbide (2-1,1-0.5,and <0.5 mm) ,silicon nitride (<0.045 mm),and graphite as raw materials.The fine particles of used iron ladle bricks were used to replace silicon nitride with the same particle size.The effects of the used iron ladle brick fine particles additions (0,12.12%,26.25%,36.38%,and 48.5%,by mass) and the heat treatment temperature (800,1 000,1 200,and 1 400 ℃) on the properties of the composite refractories were studied.The results show that:(1)with the <1 mm used iron ladle brick fine particles addition increasing,the bulk density of the samples changes slightly,the apparent porosity gradually decreases,and the cold compressive strength (CCS) and cold modulus of rupture (CMOR) first decrease and then increase;(2)with the heat treatment temperature rising,the bulk density of the samples first increases and then decreases,the apparent porosity gradually decreases,and the CCS and the CMOR increase;(3)when the temperature is 1 400 ℃ and the used iron ladle brick fine particles completely replace the silicon nitride fine particles with the same particle size,the sample exhibits the best comprehensive performance,with the bulk density of 2.37 g·cm^-3,apparent porosity of 14.3%,CCS of 31.6 MPa,and CMOR of 9.0 MPa,and it has a good resistance to the corrosion of crushed spent lithium-ion battery crushing materials at 1 000 ℃.

Key words: spent lithium battery recycling, heat treatment, SiC-Si₃N₄-C, used iron ladle brick, corrosion resistance

摘要： 回收废旧锂电池有价元素常用火法结合湿法冶金回收工艺,为提高回收工艺中热处理炉衬材料的耐腐蚀性能,以用后铁水包砖细颗粒(1~0.5、≤0.5 mm)、碳化硅(2~1、1~0.5、＜0.5 mm)、氮化硅(＜0.045 mm)和石墨为原料,将用后铁水包砖细颗粒替代同等粒度的氮化硅经800~1 400 ℃保温3 h制备SiC-Si₃N₄-C复相耐火材料。研究了用后铁水包砖细颗粒加入量(加入质量分数分别为0、12.12%、26.25%、36.38%和48.5%)和热处理温度(8 00、1 000、1 200、1 400 ℃)对复相耐火材料性能的影响。结果表明:1)随着用后铁水包砖细颗粒加入量的增加,试样体积密度变化较小,显气孔率呈现出逐渐减小的趋势,常温耐压强度和常温抗折强度先减小后增大;2)随着热处理温度的增加,试样体积密度先增加后减小,显气孔率呈现出逐渐减小的趋势,常温耐压强度和常温抗折强度增加;3)当热处理温度为1 400 ℃,用后铁水包砖细颗粒全部取代碳化硅细颗粒时,试样综合性能最佳,其体积密度、显气孔率、常温耐压强度和常温抗折强度分别为2.37 g·cm^-3、14.3%、31.6 MPa和9.0 MPa,且1 000 ℃抗废旧锂电池破碎料侵蚀性能良好。

关键词: 废旧锂电池回收, 热处理, SiC-Si₃N₄-C, 用后铁水包砖, 抗侵蚀性能