Abstract: Alkaline bismuthide is concentrated in a debismuthizing dross comprising the alkaline bismuthide and molten lead by a method involving charging the dross onto a heat-resistant screen or sieve of suitable mechanical strength. The screen has openings of such size as to enable the formation and retention thereon of a molten lead-pervious residue cake comprising particles of the alkaline bismuthide, for example of crystals of calcium magnesium bismuthide (Ca Mg.sub.2 Bi.sub.2). The dross is subjected on the screen to the influence of a partial vacuum drawn from the opposite side of the screen from the dross, and the molten lead is sucked or pulled through pore channels of the porous residue cake of the alkaline bismuthide particles which is formed on the screen, and without any significant physical compression of the cake with attendant blockage of the pores of the cake, and then through the screen openings under the influence of the partial vacuum.

Abstract: A method and apparatus for manufacturing steel and other alloys by vacuum refining are disclosed. One preferred apparatus comprises a series of vacuum chambers, one containing an electron beam heating means, and a second containing a means for adding an alloying constituent. Apparatus for melting, transferring, and casting metals is also disclosed.

Abstract: The invention comprises a method for reducing the cooling of metal and the projection of metal onto the walls in the course of degasing of liquid metals by vacuum jet, which comprises establishing, in the area of the nozzle extending into the vacuum chamber and beneath said nozzle, a magnetic field tending to contract or confine the jet admitted by the nozzle into the vacuum chamber.It further comprises an apparatus for degasing liquid metals by vacuum jet technique, comprising, around the nozzle which forms the jet between an upper ladle containing the liquid metal to be degased and the vacuum chamber containing a lower laddle or an ingot mold to receive the degased liquid metal and beneath said nozzle, a solenoid having an a.c. electric current flowing therethrough such that the electric currents induced in the liquid metal tend to contract or confine the liquid metal jet ejected from said nozzle.

Abstract: A method of refining crude cadmium by vacuum distillation in which crude cadmium is passed into a reflux condenser in which higher boiling point impurities are condensed together with a portion of pure cadmium vapor, this condensate flowing in counterflow with the crude cadmium vapor. The remaining portion of the pure cadmium vapor is subsequently condensed. The apparatus comprises an inverted U-shaped vacuum chamber having an evaporator and a reflux condenser in one leg and a further condenser in the other leg. A feed pipe for liquid crude cadmium enters the one leg adjacent the evaporator and a residue outlet pipe leaves the one leg, the feed pipe and the residue pipe being arranged so that no back-flow takes place from the residue pipe to the feed pipe. An outlet pipe for the refined cadmium issues from the other leg of the vacuum chamber.

Abstract: A method of adding a metallic additive to a molten metal having a temperature higher than the boiling point of the metallic additive comprises introduction of the metallic additive into the molten metal while the pressure within a double-walled ladle structure is adjusted to a value substantially equal to 70 to 85% of the vapor pressure evolved by the vaporization of the metallic additive. The method employs the double walled ladle structure having an adiabatic space formed between inner and outer containers which constitute the ladle structure together with a lid adapted to close the top opening of the ladle structure to enable the pressure within the ladle structure can be adjusted to the predetermined value.