| 摘要 |
<p>In a method of refining metals, a layer of refining materials which will melt at a temperature below the melting temperature of the metal to be refined is introduced into the bottom of the furnace and the metal to be refined is fed into the furnace on the top of the refining layer. The charge is then heated from above the refining material and the latter melts and forms a liquid layer at the bottom of the furnace, the metal as it melts descending through the refining layer and being thereby purified. Part of the metal may be charged into the furnace in advance of or simultaneously with the refining materials and the rest of the metal charged on the top of the refining materials. The refining materials contain sodium, potassium or barium hydroxides, singly or in combination, calcium carbide or calcite and carbon in any of its solid forms except graphite. The metals treated may be iron, steel, zinc, copper, aluminium or lead. When treating copper or aluminium, the refining materials comprise sodium carbonate or potassium hydroxide and silica.</p> |
