Preparation of Carbon Anodes for Aluminum Electrolysis by Recovered Graphite from Spent Cathode Carbon Blocks via High Pressure Leaching.

As the second largest solid waste in aluminum industry after red mud, the spent cathode carbon block has significant potential pollution hazards to the ecological environment, and is rich in a large number of high-quality graphite resources, with recycling properties. In order to realize the efficient recycling of high-quality graphite resources of spent cathode carbon block, the spent cathode carbon block was treated by high pressure leaching. The differences of physical and chemical properties of spent cathode carbon block, calcined petroleum coke and recovered graphite at different stages were systematically compared, and the recovered graphite was selected and blended with calcined petroleum coke to prepare the aluminum electrolytic carbon anode. The results show that compared with the calcined petroleum coke, the recovered graphite has similar industrial composition, phase composition and element content, but there are significant differences in crystal structure and asphalt wettability. In view of this, the performance of prepared anodes drops gradually with the increase of the amount of recycled graphite. Under the condition of low content, the recycled graphite from spent cathode carbon blocks has the feasibility and application potential of mixing and preparing aluminum electrolytic carbon anode. [ABSTRACT FROM AUTHOR]