Abstract
Aluminum is the second most produced metal after iron. China is the top producer of primary aluminum with a production capacity of 41,000 kt and an output in 2016 of 32,000 kt. A large amount of spent carbon cathode block (SCCB) is produced after electrolytic pot failure. SCCB consists of carbon, fluorides, alkali metals, carbides, nitrides, cyanides, and oxides, and is considered to be a hazardous material because it contains significant concentrations of toxic and soluble cyanides and fluorides. There is no economical and efficient process for the treatment of SCCB and is most commonly disposed in landfill. In this study, the vacuum distillation process (VDP) has been used to separate and recycle SCCB. The results show that Na3AlF6, NaF, and sodium metal can be effectively separated from SCCB by VDP, and the distillation ratio is above 80% at a distillation temperature of 1200°C. The carbon content in the distilled SCCB is above 91% and the impurities are mainly CaF2 and Al2O3.
Similar content being viewed by others
References
W.S. Rickman, Light Met. 1988, 735 (1988).
N.H. Bings, F.W. Kämpf, H. Sauer, H.W. Schmidt, J.N. Andersen, and J.B. Todd, Erzmetall 37, 435 (1984).
X. Zhai and Z. Qiu, Environ. Chem. 12, 139 (1993).
M. Sørlie and H.A. Øye, Cathodes in Aluminum Electrolysis, 3rd ed. (Dusseldorf: Aluminum-Verlag Marketing & Kommunikation GmbH, 2010).
C.A. Young, S. Nordwick, and M. Foote, Paper Presented at 4th International Conference on Materials Engineering for Resources, 2001.
W.X. Li and X.P. Chen, Light Met. 2010, 859 (2010).
N. Li, G. Xie, Z.X. Wang, Y.Q. Hou, and R.X. Li, Paper Presented at 3rd International Conference on Chemical, Metallurgical Engineering, 2013.
G. Ospina and M.I. Hassan, JOM 69, 9 (2017).
V. Mann, V. Pingin, A. Zherdev, Y. Bogdanov, S. Pavlov, and V. Somov, Light Met. 2017, 571 (2017).
G. Holywell and R. Breault, JOM 65, 11 (2013).
J.P. McGeer, V.V. Mirkovich, and N.W.F. Philips, Recovery of Material from Aluminum Reduction Cell Lining, US Patent #28581982 (1958).
A. Tabereaux, Paper Presented at the International Harald A. Øye Symposium, Eds. 1995.
X. Zhai and Z. Qiu, Environ. Chem. 12, 139 (1993).
I. Pflugmacher and H.P. Boehm, Paper Presented at 3rd Conference on Industrial Carbon and Graphite, 1970.
C.L. Yaws and M.A. Satyro, The Yaws Handbook of Vapor Pressure, 2nd ed. (Oxford: Gulf Professional Publishing, 2015).
Davida A. Schulz and Alan W. Searcy, J. Phys. Chem. 67, 103 (1963).
A.R.W. Peterson, L.C. Blayden, E.S. Martin, Light Met. 1985, 1411 (1985).
M.C.N. Cochran and R. Keller, Light Met. 1992, 549 (1992).
Acknowledgements
The authors wish to thank the Fundamental Research Funds for the Central Universities (N162502002) and the National Natural Science Foundation of China (51434005) for financial support.
Author information
Authors and Affiliations
Corresponding author
Electronic supplementary material
Below is the link to the electronic supplementary material.
Rights and permissions
About this article
Cite this article
Yaowu, W., Jianping, P. & Yuezhong, D. Separation and Recycling of Spent Carbon Cathode Blocks in the Aluminum Industry by the Vacuum Distillation Process. JOM 70, 1877–1882 (2018). https://doi.org/10.1007/s11837-018-2858-4
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11837-018-2858-4