| 摘要 |
A method for producing a high purity primary metal of aluminum which compris es charging, as a main material, an alumina having been reduced with respect to Si content by a washing treatment with an acid into an electrolytic smelting furnace of Hall-Hercult type, and, in tandem with this, using a deashing coke and/or pitch as a carbon material for an anode. In the washing with an acid, use is made of an aqueous solution of sulfuric acid, an aqueous solution containing sulfuric acid and hydrofluoric acid, or the like, and an acidic aqueous solution warmed up to 40 .degree.C or higher is preferably used for removing Si. The use of this method leads to the production of a high purity primary metal of aluminum having markedly reduced contents of Si and Fe, and thus to the production of a high purity primary metal of aluminum having a purity of 99.95 wt % (3N5) or higher, further of that havi ng a purity near the purity 4N of a secondarily refining metal.
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