the reactions will be carried out at a temperatture at which both the MAlHal4 and alkali metal are molten,the temperature preferably being adequately but not excessively above their melting points,the alkali metal halide and aluminum typically being present in solid form.the alkali metal halide may be in more or less finely divided particulate form but the aluminum is conveniently present as a unitary mass,so that it may act as a terminal for the external circuit.for the other end of the external circuit a stainless steel or aluminum terminal may be provided,extending into the molten alkali metal.