Methods for degassing and for removing impurities from molten metals are disclosed. These methods can include operating an ultrasonic device in a molten metal bath, and adding a purging gas into the molten metal bath in close proximity to the ultrasonic device.

An apparatus and method are described for effectively priming a non-electrically conductive filter for removal of solid inclusions from liquid metal. In one embodiment, the ceramic filter media is surrounded by a low frequency induction coil (1-60 Hz) with its axis aligned in the direction of the net metal flow. The coil is positioned to enhance the heating of any metal frozen onto, or in the pores of, the filter element. In one embodiment, the coil is positioned in order to generate Lorentz forces, which act to cause heated metal to impinge on the upper surface of the filter element, enhancing the priming action. Once a filter equipped with such a coil has been primed, it can be kept hot or reheated, and subsequently reused during several batch tapping sequences.

A semi-liquid metal processing apparatus and method are presented in which a semi-liquid metal and/or semi-solid metal is introduced into a crucible and his electromagnetically stirred at a first frequency while cooling, and thereafter sidewalls of a metal charge formed of the semi-liquid metal and/or semi-solid metal are partially melted prior to tilting the crucible for removal of the metal charge.

The invention relates to a process for the extraction of gold and silver from ores and mining by-products. The process according to invention consists in treating ores and mining residues having a content of 0.5 . . . 12 ppm Au with a solution of ammonium thiosulphate, recycled at a temperature of 15-25 C.; the filtrate resulting after solubilization is subjected to an electrolytic extraction with high-alloy electrodes with a current density of 200 . . . 250 A/m.sup.2, until the electrolyte reach a concentration of 5-15 ppm Au, 1-100 ppm Ag and 0.1-1.0 g/1 Cu; afterwards, the separated cement is filtered off and dissolved in aqueous ammonia, dried at a temperature of 105 C. and melted at a temperature of 1200 C., resulting a Au-Ag alloy, which is processed by electrochemical and thermal refining operations, from which there are obtained Au and Ag of high purity.

The invention relates to a process for the extraction of gold and silver from ores and mining by-products. The process according to invention consists in treating ores and mining residues having a content of 0.5 . . . 12 ppm Au with a solution of ammonium thiosulphate, recycled at a temperature of 15-25 C.; the filtrate resulting after solubilization is subjected to an electrolytic extraction with high-alloy electrodes with a current density of 200 . . . 250 A/m.sup.2, until the electrolyte reach a concentration of 5-15 ppm Au, 1-100 ppm Ag and 0.1-1.0 g/1 Cu; afterwards, the separated cement is filtered off and dissolved in aqueous ammonia, dried at a temperature of 105 C. and melted at a temperature of 1200 C., resulting a Au-Ag alloy, which is processed by electrochemical and thermal refining operations, from which there are obtained Au and Ag of high purity.

Provided is a method for producing cathode copper. The method comprises a smelting step including feeding sulfidic copper bearing material and oxygen-bearing reaction gas into a suspension smelting furnace, to produce blister copper, a fire refining step including feeding blister copper into an anode furnace to produce molten anode copper, an anode casting step to produce cast anodes, a quality checking step for dividing cast anodes into accepted cast anodes and rejected cast anodes, an electrolytic refining step including subjecting accepted cast anodes to electrolytic refining in an electrolytic cell to produce cathode copper and as a by-product, spent cast anodes, and a recycling step for recycling anode copper of rejected cast anodes and anode copper of spent cast anodes.

A process for production of a PGM (platinum group metal)-enriched alloy containing iron and PGM(s) (platinum, palladium and/or rhodium) includes steps of: (1) providing a sulfur-free PGM collector alloy, (2) providing a copper- and sulfur-free material capable of forming a molten slag-type composition including silicon dioxide and magnesium and/or calcium oxide, (3) melting the PGM collector alloy and slag-forming material within a converter until a multi-phase system of a lower high-density molten mass of PGM collector alloy and an upper low-density molten mass of slag-type composition has formed, (4) contacting an oxidizing gas with the lower high-density molten mass of step (3) until conversion of the PGM collector alloy into a PGM-enriched alloy, (5) separating an upper molten slag formed in step (4) from the PGM-enriched alloy by difference in density, (6) allowing the separated molten masses to cool down and solidify, and (7) collecting the solidified PGM-enriched alloy.

A device for producing metal powder. This includes a melting chamber, a downstream atomization tower, and a nozzle assembly for atomizing a melt jet. The device further includes an induction coil disposed within the melting chamber and operated at a melting frequency f.sub.melt, the induction coil is adapted to locally melt a material rod at least section-wise received therein, to produce the melt jet to be atomized, and a separate intermediate coil disposed within the melting chamber and operated at a base frequency f.sub.base, wherein said intermediate coil is disposed downstream of the induction coil and aligned coaxially with the induction coil. The intermediate coil is configured to superheat the melt jet in a region between the induction coil and the nozzle assembly. The following applies to a frequency ratio F.sub.BS of the base frequency f.sub.base to the melting frequency f.sub.melt, 1F.sub.BS=f.sub.base/f.sub.melt500.

A device for producing metal powder. This includes a melting chamber, a downstream atomization tower, and a nozzle assembly for atomizing a melt jet. The device further includes an induction coil disposed within the melting chamber and operated at a melting frequency f.sub.melt, the induction coil is adapted to locally melt a material rod at least section-wise received therein, to produce the melt jet to be atomized, and a separate intermediate coil disposed within the melting chamber and operated at a base frequency f.sub.base, wherein said intermediate coil is disposed downstream of the induction coil and aligned coaxially with the induction coil. The intermediate coil is configured to superheat the melt jet in a region between the induction coil and the nozzle assembly. The following applies to a frequency ratio F.sub.BS of the base frequency f.sub.base to the melting frequency f.sub.melt, 1F.sub.BS=f.sub.base/f.sub.melt500.

A coupling has an opening and a protrusion extending downward from the opening. The protrusion has threads that are preferably positioned outside of the opening. A rotor shaft that connects to the coupling has an internal bore with threads that receives and retains the protrusion, such as by a threaded connection between the two, so the protrusion applies driving force to the shaft.