Co-disposal Research of Red Mud and Aluminum Electrolysis Solid Waste Based on External Thermal Reduction and Smelting Separation
Abstract In large aluminum smelting enterprises, the solid wastes of red mud and waste cathodes are satisfied the basic elements requirements of the solid-solid direct reduction technology. Thus, it is proposed a solution to use waste cathodes and red mud under indirect heating supply to produce pellets and to utilize in situ. It has been studied the reduction mechanism of red mud and waste cathode, the influence of carbon allocation method on pellet reduction and the research of the smelting separation and product quality. Experiment shows that the iron of red mud can be successfully reduced by waste cathode and anode toner at high temperature. The metallization rate of iron in red mud can reach more than 95% and the quality of pellets is more suitable with the mode of external carbon mixing. In order to carry out effective melting and separation of slag and iron, the red mud pellets must to be briquetted or to reserve a molten pool before charging into the melting furnace. After separation, the content of iron and carbon in steel can reach about 98.85% and 0.13% respectively, and the yield of iron elements can reach more than 96%, the harmful components flow into the slag can be effectively solidified. Content of alumina in the slag reached about 37% which can be economically recycled to the alumina purification process as a matching.