Method of obtaining refined aluminium, starting from aluminium alloy scrap

摘要

630,891. Electrolyte refining of aluminium. COMPAGNIE DE PRODUITS CHIMIQUES ET ELECTROMETALLURGIQUES ALAIS, FROGES & CAMARGUE. Dec. 30, 1946, No. 37983. Convention date, Dec. 3, 1945. Drawings to Specification. [Class 41] In the three-layer method of refining aluminium from aluminium alloy scrap, scrap is added to the anodic layer in excess of the quantity of alloy treated corresponding to the quantity of refined metal produced at the cathode such that as a result of the progressive increase of its depth, the anodic layer preserves a content of the heavy constituent (e.g. copper or zinc) lower than the value (40 per cent for Cu) incompatible with the purity of the refined aluminium. The initial depth of the anodic layer may be the minimum depth through which the alloy to be treated will sufficiently rapidly diffuse during the recharging step and the increase in depth of the anodic layer during the working of the cell may be equal to the depth of the electrolyte layer. The anodic alloy may be renewed by drawing off a portion thereof and diluting, as regards the heavy constituent (e.g. Cu or Zn), the remaining portion by the addition of alloy to be treated. Arrangements are provided for lifting the cathode block making contact with the refined aluminium as the bottom layer of alloy and hence the layer of refined aluminium rises and comprise a crank-wheel for lifting a rod supporting the block. Specification 405,596 is referred to.