Improvements in or relating to the process of smelting of metal and a furnace therefor

摘要

662,634. Melting and refining metals. WEIL, W. M. June 27, 1947. [July 12, 1946] No. 17014/47. Class, 82(i). [Also in Groups XI and XII] Metals such as aluminium are melted and refined in a reverberatory furnace (see Group XII), which in one form, Figs. 2 and 3, comprises a main heating chamber, which normally contains a pool of molten metal B, and an auxiliary open chamber having a hearth 18 arranged at substantially the same level as the main hearth 1 and divided by a partition 40 into two compartments adapted to contain pools of metal C and A and communicating with the main chamber through passages 20 and 21 respectively. The passage 21 is provided with a vertically-movable door 22 which is normally so positioned as to prevent flow of slag from the surface of the pool A into the main chamber. Molten metal may be withdrawn from the pool C through vertical passages 23, 24 and caused to flow upwardly through a central passage 26 by means of an electromagnetic induction pump, (see Group XI), which also effects heating of the metal in the passages. The passage 26 communicates with a pipe 37 through which a stream of metal may be directed into the pool A over a lip 38 formed on the partition 40. In operation, solid metal to be melted is charged into the pool A adjacent the partition and is engulfed by or mixed with molten metal fed through the pipe 37, fluxing or refining agents being added to the resulting pasty mass. Charging is then discontinued for a period sufficient to allow liquefaction of the mass, the impurities rising to the surface being skimmed off and the refined material flowing into the heating chamber where it may be tapped off. Molten solid metal may then be charged and the process repeated. In a second form, Fig. 7 suitable for a continuous process, metal is withdrawn from a pool D in the auxiliary chamber by an electrically-driven pump 76 and supplied to a manifold 82 having lateral branches 83 and 84, controlled by gate valves 85 and 86, from which the metal may be discharged tangentially into a hopper 72, 73 and into the pool E respectively. Solid metal to be melted together with fluxing and refining agents is fed continuously into the hopper and becomes mixed with the molten metal due to the whirling motion induced by the discharge from the branch 83, the resulting pasty mass passing through opening 75 into the pool E where it is liquefied by the stream of metal from the branch 84. At this stage the metal is puddled and the slag skimmed off, the refined metal passing into the main chamber through the passage 22. Further refining agents may be introduced through the branch 84. Specifications 542,347 and 632,947, [Group Xi], are referred to.