工程科学学报.第42卷，第6期：731-738.2020年6月 Chinese Journal of Engineering,Vol.42,No.6:731-738,June 2020 https://doi.org/10.13374/j.issn2095-9389.2019.06.10.002;http://cje.ustb.edu.cn 铝电解槽废阴极炭块电-热耦合处理过程数值模拟 卢婷婷，李荣斌，赵洪亮，谢明壮，刘风琴四 北京科技大学治金与生态工程学院，北京100083 ☒通信作者，E-mail:liufq@ustb.edu.cn 摘要废阴极炭块是铝电解槽大修时产生的一种危险固体废弃物，对其进行安全处置和资源化利用的关键是深度分离其 中的有价组分炭和氟化盐。采用火法工艺对废阴极炭块进行处理，明确了氟化盐的挥发温度.基于氟化盐的挥发析出性质， 设计了高温热处理电阻炉，并对其传热特性、控温规律以及氟化盐有效挥发区域进行了三维数值解析.实验确定氟化物的有 效挥发温度为≥1700℃，该温度段下其挥发率可达93.1%以上.通过模拟不同供电模式下炉内温度场的演变规律，得到：在 12V升温24h,9V保温12h的供电条件下，升温阶段炉内最高温度可达2250℃，氟化盐理论挥发区域占比可达98%：采用 逐级递减的电压供给制度可以保证1700℃以上温度区域维持20，大幅度延长了有效热处理时间，有利于废阴极炭块中炭 与氟化盐的深度分离 关键词废阴极炭块：数值模拟：高温电阻炉：电-热耦合：温度场 分类号TF09 Numerical simulation of electro-thermal coupling process for spent cathode carbon block from aluminum electrolysis cell LU Ting-ting,LI Rong-bin.ZHAO Hong-liang.XIE Ming--huang.LIU Feng-gin School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China Corresponding author,E-mail:liufq @ustb.edu.cn ABSTRACT Spent cathode carbon block(SCCB)is considered to be a kind of hazardous waste,because it contains a large amount of soluble fluoride salts and toxic cyanides.The life of an aluminum electrolytic cell is generally 5-8 years,and the SCCB would be produced during the overhaul of the cell.Currently,most SCCBs are piled in landfills or stored for disposal in China.The unreasonable disposal of SCCBs will cause serious pollution and damage to the ecological environment,and wastage of valuable carbon material and fluoride salts.The key to the safe disposal and resource utilization of SCCBs is to separate the carbon and fluoride salts deeply.In this study,SCCB was treated by the pyrometallurgical process,and the characteristics of volatilization temperature of fluoride salts were firstly experimentally determined.For a laboratory-scale self-designed high temperature resistance furnace,a three-dimensional model was built and numerical calculation was performed.The heat transfer characteristics,temperature control law and effective volatilization region of fluoride salts were analyzed in detail.The experimental results demonstrate that the effective volatilization temperature of fluoride is higher than 1700 C,and the volatilization rate is higher than 93.1%.By simulating the evolution of the temperature field in the furnace under different power supply modes,it is obtained that under the power supply condition of heating at 12 V for 24 h and holding9 V for 12 h,the maximum temperature in the furnace during the heating phase can reach 2250 C,and the theoretical volatilization volume of fluoride salts can reach 98%.After optimization,a step-by-step decreasing mode of power supply can improve the efficiency of treating SCCBs.Moreover,the treating temperature can be maintained for 20 h at 1700 C,which is beneficial to the 收稿日期：2019-06-10 基金项目：中央高校基本科研业务费专项资金资助项目(2302018FRF-TP.18-095A1):宁夏回族自治区重点研发计划资助项目(2018BDE02050)铝电解槽废阴极炭块电−热耦合处理过程数值模拟 卢婷婷，李荣斌，赵洪亮，谢明壮，刘风琴苣 北京科技大学冶金与生态工程学院，北京 100083 苣通信作者，E-mail：liufq@ustb.edu.cn 摘    要    废阴极炭块是铝电解槽大修时产生的一种危险固体废弃物，对其进行安全处置和资源化利用的关键是深度分离其 中的有价组分炭和氟化盐. 采用火法工艺对废阴极炭块进行处理，明确了氟化盐的挥发温度. 基于氟化盐的挥发析出性质， 设计了高温热处理电阻炉，并对其传热特性、控温规律以及氟化盐有效挥发区域进行了三维数值解析. 实验确定氟化物的有 效挥发温度为≥1700 ℃，该温度段下其挥发率可达 93.1% 以上. 通过模拟不同供电模式下炉内温度场的演变规律，得到：在 12 V 升温 24 h，9 V 保温 12 h 的供电条件下，升温阶段炉内最高温度可达 2250 ℃，氟化盐理论挥发区域占比可达 98%；采用 逐级递减的电压供给制度可以保证 1700 ℃ 以上温度区域维持 20 h，大幅度延长了有效热处理时间，有利于废阴极炭块中炭 与氟化盐的深度分离. 关键词    废阴极炭块；数值模拟；高温电阻炉；电−热耦合；温度场 分类号    TF09 Numerical simulation of electro−thermal coupling process for spent cathode carbon block from aluminum electrolysis cell LU Ting-ting，LI Rong-bin，ZHAO Hong-liang，XIE Ming-zhuang，LIU Feng-qin苣 School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China 苣 Corresponding author, E-mail: liufq@ustb.edu.cn ABSTRACT    Spent cathode carbon block (SCCB) is considered to be a kind of hazardous waste, because it contains a large amount of soluble fluoride salts and toxic cyanides. The life of an aluminum electrolytic cell is generally 5−8 years, and the SCCB would be produced during the overhaul of the cell. Currently, most SCCBs are piled in landfills or stored for disposal in China. The unreasonable disposal of SCCBs will cause serious pollution and damage to the ecological environment, and wastage of valuable carbon material and fluoride salts. The key to the safe disposal and resource utilization of SCCBs is to separate the carbon and fluoride salts deeply. In this study, SCCB was treated by the pyrometallurgical process, and the characteristics of volatilization temperature of fluoride salts were firstly experimentally determined. For a laboratory-scale self-designed high temperature resistance furnace, a three-dimensional model was built and numerical calculation was performed. The heat transfer characteristics, temperature control law and effective volatilization region of fluoride salts were analyzed in detail. The experimental results demonstrate that the effective volatilization temperature of fluoride is higher than 1700 ℃, and the volatilization rate is higher than 93.1%. By simulating the evolution of the temperature field in the furnace under different power supply modes, it is obtained that under the power supply condition of heating at 12 V for 24 h and holding 9 V for 12 h, the maximum temperature in the furnace during the heating phase can reach 2250 ℃, and the theoretical volatilization volume of fluoride salts can reach 98%. After optimization, a step-by-step decreasing mode of power supply can improve the efficiency of treating SCCBs. Moreover, the treating temperature can be maintained for 20 h at 1700 ℃, which is beneficial to the 收稿日期: 2019−06−10 基金项目: 中央高校基本科研业务费专项资金资助项目（2302018FRF-TP-18-095A1）；宁夏回族自治区重点研发计划资助项目（2018BDE02050） 工程科学学报，第 42 卷，第 6 期：731−738，2020 年 6 月 Chinese Journal of Engineering, Vol. 42, No. 6: 731−738, June 2020 https://doi.org/10.13374/j.issn2095-9389.2019.06.10.002; http://cje.ustb.edu.cn