A method for the preparation of starting materials for carbothermal reduction methods

摘要

In the prodn. of non-ferrous metals by reacting the oxide with C at high temp. the rate of the redn. is improved by using a pre-treated starting material. The pretreatment comprises mixing the oxide material in the original state for example as carbonate, or hydroxide, with a liquid hydrocarbon fluid and heating the mixt. under exclusion of air in order to at least partially dissociate the hydroxide and carbonate and pyrolyse the hydrocarbon substance. The oxide material, which is pref. Al hydrate, has a particle size of 100-200 mu and is mixed with heavy duty oil of low volatility. The mixt is heated by contacting with the waste gases from the reduction process and charged directly to the reaction chamber for the prodn. of Al by reacting with C. The method produces a starting material which facilitates arcing and the use of graphite electrodes in the subsequent reduction process. The redn. is shortened when using a plasma column for the reaction, and in both cases the ratio of C to oxide will not be critical.