Method using single furnace carbothermic reduction with temperature control within the furnace

摘要

A start-up process of making aluminum using a single carbothermic reactor/furnace ( 11 ) having a single hollow reactor compartment with bottom resistance heating electrodes ( 16 ) ( 13 ) in the side of the reactor, involves adding Al₂O₃ and C (carbon) for start-up and melting the mixture to provide a (Al₂O₃-Al₄C₃) slag having a temperature between about 1875° C. and 2000° C.; and then adding Al₄C₃ to the slag and raising the temperature of the furnace ( 11 ) to form a top Al phase with 6 to 8 wt % C ( 21 ) and a bottom slag phase ( 22 ); and then adding Al₂O₃ is added to the Al-C/slag ( 21, 22 ) to produce an Al₂O₃ rich slag lower the reactant temperature and produce a decarbonization reaction (step 30 ) providing a top Al phase with less than 5 wt % C ( 23 ) which is then tapped after step ( 40 ). The remaining slag is the starting material.