| 摘要 |
<p>A method of recovering Zn entangled in the dross from a galvanizing bath comprises reacting the dross with Al or an Al alloy, such as Al-Si, where Si=5 per cent, to form an Al-Fe alloy and free the combined Zn, simultaneously or subsequently dissolving the Zn in molten Pb at high temperature, and then cooling the Pb to throw the Zn out of solution. Preferably, to a bath of molten Pb at a temperature of 350-400 DEG C. is added an amount of dross equal to about 10 per cent of the weight of the Pb, together with an amount of Al equal to about 1 1/2 times the weight of Fe in the dross. The temperature of the bath is then raised to above 700 DEG C., the Al-Fe alloy formed is swept aside or removed from the surface of the bath, the bath is cooled to below 420 DEG C., and the solid Zn, which separates out on top of the still molten Pb, is removed. This final removal may be effected by lowering into the bath of molten metal a steel frame partly open at the top and bottom, the walls of the frame extending above and below the surface of the bath, transferring molten Zn on the bath surface outside the walls to within the frame and, subsequent to the freezing of the Zn, lifting the frame with the cake of solid Zn within it out of the bath.</p> |
