Investigation on air reactivity and electrolysis consumption of anode carbons with anthracite additions

Abstract

The increasing price of coke raw materials and a shortage in local supply for anode manufacture has presented a long term challenge for aluminum smelters with added cost into the metal product. The aim of this work is to search alternative carbon raw materials to replace part of traditional coke raw materials or technology to reduce the material costs for the prebaked anodes. Some calcined anthracite was selected as a starting material chemically pretreated to remove its impurities. The pretreated anthracite was added to the carbon mixtures, formed, and baked into the anode samples using the process used in the existing industry. The air-reactivity and anode consumption were tested. The anode samples were also characterized using XRD and SEM to investigate microstructure and inner pores. The results show that the anodes with anthracite additions of 10 - 20 wt. % are promising for potential application. In addition, ultrasound is found to reduce the anode consumption due to its effect on removing the CO2 gas bubbles.