Abstract: Apparatus for the continuous vacuum refining of a metal comprising a cylindrical vacuum chamber, containing a stack of a plurality of vertically superposed trays. The trays receive impure molten metal which flows downwardly from tray to tray while impurities are discharged therefrom and flow to shields which surround the trays and condense and discharge the impurities. The metal in the trays is heated to evaporate the impurities therefrom. The heat energy which is imparted to the metal is effected irregularly along the height of the stack of the trays such that the imparted heat energy diminishes in a vertically downwards direction.

Abstract: The present invention relates to apparatus for continuous refining of tin.The apparatus comprises a vacuum chamber accommodating an evaporator which is a vessel with a granulated loose material filling the entire vessel volume to provide a maximum evaporating surface washed by molten metal being refined, with the vessel side walls being fitted with outlets for the effluence of impurity vapors, referred to hereinafter as volatilized impurities, liberated from said metal evaporating surface, and with the vessel bottom having drains for discharging refined metal from the vacuum chamber.

Abstract: Apparatus for the continuous refining of metals, such as, lead, tin, comprising a distillation column built up of identical boxes set up one upon another and forming evaporation stages along which the metal flows off sequentially in the form of a thin film. Extending through all the column boxes are preferably three graphite heater rods set up in a row, the heater being preferable connected in a three-phase electric circuit. The heating of the metal film is conducive to the distillation of impurity vapors, referred to as volatilized impurities, flowing to condensing shields.

Abstract: The present invention relates to apparatus for continuous purifying of tin from impurities -- lead and bismuth, by refining.The apparatus comprises a vacuum chamber accommodating a range of trays arranged in succession and fitted each with an overflow conduit disposed in its side wall at a certain distance from its upper end face, with the overflow conduit communicating with the tray space and being positioned parallel to the tray axis and with the overflow conduit outlet being connected to the underlying tray and a tray column being encompassed with an induction coil establishing a magnetic field under whose effect the metal rotates climbing to the level of the overflow conduit.