Editors: | Kongoli F, Feng N, Polyakov P, Gaune-Escard M |
Publisher: | Flogen Star OUTREACH |
Publication Year: | 2016 |
Pages: | 180 pages |
ISBN: | 978-1-987820-40-9 |
ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
Chinese aluminum reduction industry has developed rapidly in the decades. It has made a great contribution to the development of national economy and people¡¯s living, yet produced a lot of waste as well. The spent cathode of aluminum reduction is the largest amount of solid waste when the cell shutting and relining, and it contains some dangerous substances such as fluoride and cyanide which may cause serious environmental and safe problems, so harmless treatment on spent cathode has become an urgent and serious problem for Chinese aluminum refiners. Yet from the perspectives of resource, there are also a lot of value materials such as graphite, cryolite and alumina in the spent cathode, so it is also very important to recovery valuable substances from spent cathode of aluminum reduction. In this paper, current processing methods of harmless treatment and resource recovery for spent cathode of aluminum reduction were reviewed, and future development trend was also predicted. The main problem to be resolved for harmless treatment is to decrease the cost of industrial application. For hydrometallurgical treatments such as leaching and flotation, the key is to improve the recovery ratio and grade of recovered carbon powder and cryolite for further usage. It is a promising method and worth exploring further for adding a certain amount of spent cathode into the sintering process of alumina production, of which sodium and aluminum can be recovered together, graphite acts as a reductant of high ignition point and fuel, and fluoride becomes an improving agent of the sintering process.