A milliseconds flash joule heating method for the regeneration of spent cathode carbon

Abstract

Spent cathode carbon (SCC) blocks of aluminum electrolytic cell were hazardous waste produced in the production of electrolytic aluminum. In this present work, a facile, rapid, and economical strategy was proposed to remove fluoride and other toxic substances in the SCC block by the flash joule heating method. SCC after flash joule heating (F-SCC) were prepared in different flash voltages and number of passes; the chemical composition, microscopic morphology and carbon configuration of the SCC and F-SCC were described in detail. The results show that the purification efficiency depends upon the flash voltages and pass number. In terms of flash voltage, 150 V (5.62 kJ/g) is the optimal voltage to maintain the micro-expansion characteristics of the cathode carbon. Multiple flash joule heating can not only maintain its high-graphitization carbon, but also improve its micro-expansion characteristics. In addition, the electrochemical performance of F-SCC was characterized, and F-SCC displayed excellence capacitance performance. The low-cost, rapid -regeneration method based on the flash joule heating provides an effective method for the clean recycling and high-value utilization of carbonized solid waste.

Keywords:

• Spent cathode carbon
• flash joule heating
• purification
• capacitance performance

Acknowledgments

This work was supported by Fundamental Research Funds for the Central Universities (China University of Mining and Technology) (2019GF08), National Natural Science Foundation of China (51974307), Key Research and Development Project of Xuzhou City (KC21287), the Assistance Program for Future Outstanding Talents of China University of Mining and Technology (2021WLJCRCZL038) and the Postgraduate Research & Practice Innovation Program of Jiangsu Province (KYCX21_2426).

Data availability statement

The raw/processed data required to reproduce these findings cannot be shared at this time as the data also forms part of an ongoing study.

Additional information

Funding

This work was supported by Fundamental Research Funds for the Central Universities (China University of Mining and Technology) (2019GF08), National Natural Science Foundation of China (51974307), Key Research and Development Project of Xuzhou City (KC21287), the Assistance Program for Future Outstanding Talents of China University of Mining and Technology (2021WLJCRCZL038) and the Postgraduate Research & Practice Innovation Program of Jiangsu Province (KYCX21_2426).