The reductive smelting of red mud is calculated and investigated regarding the necessary amount of reduction agents and the final composition of the pig iron phase and the mineral (slag) phase as products of the process. Liquidus temperatures of slags with three different compositions are calculated during the reduction process and in dependency of the remaining sodium content in the slag. All calculations were done with FactSage and the results are confirmed by smelting experiments in a lab scale electric arc furnace.