A hydrometallurgical method for simultaneously extracting zinc, lead, silver, iron and calcium from electric arc furnace dust (hazardous waste) produced by the steelmaking industry (steelworks), in the form of industrial products: zinc as zinc sulphate or zinc cathodes; lead and silver as a concentrate of lead and silver; iron as reduced elemental iron for return to the electric arc furnace; and, lastly, calcium as gypsum, without solid waste or liquid effluents being generated relates to the chemical nature of the electric arc furnace dust (complex oxides) changes to a sulfide complex, and eliminating the hazards associated with the generation of fugitive heavy-metal salts. In addition, the hydrometallurgical problem of low recovery of zinc and iron is solved. Consequently, hydrometallurgy is made easier and more environmentally friendly, as condensed water is used as a leachate, the condensed water being continuously regenerated by vacuum evaporation systems without generating effluents.

A hydrometallurgical method for simultaneously extracting zinc, lead, silver, iron and calcium from electric arc furnace dust (hazardous waste) produced by the steelmaking industry (steelworks), in the form of industrial products: zinc as zinc sulphate or zinc cathodes; lead and silver as a concentrate of lead and silver; iron as reduced elemental iron for return to the electric arc furnace; and, lastly, calcium as gypsum, without solid waste or liquid effluents being generated relates to the chemical nature of the electric arc furnace dust (complex oxides) changes to a sulfide complex, and eliminating the hazards associated with the generation of fugitive heavy-metal salts. In addition, the hydrometallurgical problem of low recovery of zinc and iron is solved. Consequently, hydrometallurgy is made easier and more environmentally friendly, as condensed water is used as a leachate, the condensed water being continuously regenerated by vacuum evaporation systems without generating effluents.

A unique sequence of steps is provided to reduce contaminants along one or more surfaces and faces of gold evaporative sources without deleteriously impacting the structure of the gold evaporative sources. Edges are deburred; contaminants are successfully removed therealong; and surface smoothness is substantially retained. The resultant gold evaporative source is suitable for use in evaporative processes as a precursor to gold film deposition without the occurrence or a substantial reduction in the likelihood of spitting by virtue of significantly reduced levels of contaminants, in comparison to gold evaporative sources subject to a standard cleaning protocol.

A unique sequence of steps is provided to reduce contaminants along one or more surfaces and faces of gold evaporative sources without deleteriously impacting the structure of the gold evaporative sources. Edges are deburred; contaminants are successfully removed therealong; and surface smoothness is substantially retained. The resultant gold evaporative source is suitable for use in evaporative processes as a precursor to gold film deposition without the occurrence or a substantial reduction in the likelihood of spitting by virtue of significantly reduced levels of contaminants, in comparison to gold evaporative sources subject to a standard cleaning protocol.

A method of selectively oxidizing one or more target metals in an alloy comprising target and non-target metals is provided. The method comprises the steps of: i) melting the alloy and exposing the molten alloy to simultaneous fragmentation and oxidation in the presence of an oxygenated atomizing gas under conditions sufficient to yield an oxidation potential that oxidizes the one or more target metals in the alloy and does not oxidize the non-target metal(s); and ii) allowing the treated alloy to solidify. The method is useful to purify a non-target base metal. The method is also useful to produce a metal compound comprising a desired content of one or more oxidized target metals above the theoretical maximum generally achieved by thermal plasma spray surface coating applications.

A method of selectively oxidizing one or more target metals in an alloy comprising target and non-target metals is provided. The method comprises the steps of: i) melting the alloy and exposing the molten alloy to simultaneous fragmentation and oxidation in the presence of an oxygenated atomizing gas under conditions sufficient to yield an oxidation potential that oxidizes the one or more target metals in the alloy and does not oxidize the non-target metal(s); and ii) allowing the treated alloy to solidify. The method is useful to purify a non-target base metal. The method is also useful to produce a metal compound comprising a desired content of one or more oxidized target metals above the theoretical maximum generally achieved by thermal plasma spray surface coating applications.

A method for purifying a powder including grains and contaminants, includes preparing a suspension including the metal powder and a solvent; then while applying mechanical energy to the suspension; dispersing the grains and the contaminants in the solvent; removing the contaminants and the solvent, and drying the grains under a controlled atmosphere.

A method for purifying a powder including grains and contaminants, includes preparing a suspension including the metal powder and a solvent; then while applying mechanical energy to the suspension; dispersing the grains and the contaminants in the solvent; removing the contaminants and the solvent, and drying the grains under a controlled atmosphere.

A method of removing hydrogen interstitially dissolved within an object can include: positioning a sorption pad having a contact surface and comprising a sorptive material; urging the contact surface into metallurgical contact with the first target surface while at a treatment temperature that is greater than about 200 degrees Celsius; c) maintaining the metallurgical contact for a treatment period during which the hydrogen migrates from the target object to the sorptive material; and at the conclusion of the treatment period, separating the contact surface from the first target surface and moving the sorption pad and any hydrogen sequestered therein away from the object.

A method of removing hydrogen interstitially dissolved within an object can include: positioning a sorption pad having a contact surface and comprising a sorptive material; urging the contact surface into metallurgical contact with the first target surface while at a treatment temperature that is greater than about 200 degrees Celsius; c) maintaining the metallurgical contact for a treatment period during which the hydrogen migrates from the target object to the sorptive material; and at the conclusion of the treatment period, separating the contact surface from the first target surface and moving the sorption pad and any hydrogen sequestered therein away from the object.