A method for producing copper metal from copper concentrates without generating waste by: (a) oxidizing copper concentrate; (b) cleaning and cooling the gases; (c) feeding to a reduction reactor; (d) cleaning the gases; (e) discharging hot powders and calcines into water; (f) performing magnetic separation; (g) thickening and filtering the magnetic fraction; (h) floating silica and inert materials; (i) thickening and filtering the silica and inert materials; (j) thickening and filtering the final concentrate containing the copper metal and noble metals; (k) smelting the final concentrate of copper and noble metals; and (l) recirculating ground smelt slag to a roasting reactor.

Oxygen is injected into the windbox of a fluidized bed ore roaster to form a fluidizing and oxidizing gas stream of elevated oxygen content which is fed into only the feed zone into which the ore to be fluidized is fed.

Oxygen is injected into the windbox of a fluidized bed ore roaster to form a fluidizing and oxidizing gas stream of elevated oxygen content which is fed into only the feed zone into which the ore to be fluidized is fed.

A process for recovering zinc from a zinc containing material, the process including the steps of: leaching the zinc containing material with an alkaline lixiviant comprising an aqueous mixture of NH.sub.3 and NH.sub.4Cl, or ionic equivalent, having a NH.sub.4Cl concentration of between about 10 g/L and about 150 g/L H.sub.2O and a NH.sub.3 concentration of between 20 g/l H.sub.2O and 250 g/L H.sub.2O, to produce a zinc containing leachate; stripping ammonia from the leachate to produce a stripped liquor which includes a zinc containing precipitate, the stripped liquor having a NH.sub.3 concentration of between 7 and 30 g/L H.sub.2O; and recovering the zinc from the stripped liquor.

A process for recovering zinc from a zinc containing material, the process including the steps of: leaching the zinc containing material with an alkaline lixiviant comprising an aqueous mixture of NH.sub.3 and NH.sub.4Cl, or ionic equivalent, having a NH.sub.4Cl concentration of between about 10 g/L and about 150 g/L H.sub.2O and a NH.sub.3 concentration of between 20 g/l H.sub.2O and 250 g/L H.sub.2O, to produce a zinc containing leachate; stripping ammonia from the leachate to produce a stripped liquor which includes a zinc containing precipitate, the stripped liquor having a NH.sub.3 concentration of between 7 and 30 g/L H.sub.2O; and recovering the zinc from the stripped liquor.

Oxygen is injected into the windbox of a fluidized bed ore roaster to form a fluidizing and oxidizing gas stream of elevated oxygen content which is fed into only the feed zone into which the ore to be fluidized is fed.

Oxygen is injected into the windbox of a fluidized bed ore roaster to form a fluidizing and oxidizing gas stream of elevated oxygen content which is fed into only the feed zone into which the ore to be fluidized is fed.

A process and its relating plant for recycling zinc oxide residues. Thereby, zinc oxide residues are granulated to particles with a size of d.sub.80 between 0.3 and 5 mm, preferably between 0.5 and 2 mm. These particles are fed into a roaster where they are thermally treated at a temperature in the range of 500 and 1.200? C., preferably 800 to 1.100? C. in a fluidized bed to form a calcine. The zinc oxide residues are zinc oxide dusts with a particle size below d.sub.80 100 ?m, preferably below d.sub.80 75 ?m coming from kiln, submerges lances furnaces, ferric reduction furnaces, galvanizing and/or recycling processes, particularly recycling of steel, copper, lead, nickel and/or electronic scrap, and/or that the zinc oxide residues comes from foundry for lead and zinc, ashes and/or dross from a Zamac process, oxide zinc ash, catalysts, melting and casting of Zn and/or zinc slag.

A process and its relating plant for recycling zinc oxide residues. Thereby, zinc oxide residues are granulated to particles with a size of d.sub.80 between 0.3 and 5 mm, preferably between 0.5 and 2 mm. These particles are fed into a roaster where they are thermally treated at a temperature in the range of 500 and 1.200? C., preferably 800 to 1.100? C. in a fluidized bed to form a calcine. The zinc oxide residues are zinc oxide dusts with a particle size below d.sub.80 100 ?m, preferably below d.sub.80 75 ?m coming from kiln, submerges lances furnaces, ferric reduction furnaces, galvanizing and/or recycling processes, particularly recycling of steel, copper, lead, nickel and/or electronic scrap, and/or that the zinc oxide residues comes from foundry for lead and zinc, ashes and/or dross from a Zamac process, oxide zinc ash, catalysts, melting and casting of Zn and/or zinc slag.

A method and recovering method of recovering zinc oxides and other metal oxides having an injection chamber where a mixture of natural gas and oxygen is formed and then ignited to form high temperature combustion gases of greater than 2000 C. with a high concentration of carbon monoxide. Then, the mixture is transported through a quiescent chamber to a feed chamber where the ignited high temperature combustion gases are mixed with finely divided material, including EAF dust. The mixture is transported to a reaction chamber, wherein zinc vapor and other metal vapors and molten slag particles are formed. The zinc vapor and other metal vapors are separated from the molten slag particles and transported to an insulated plenum. Zinc vapor and other metal vapors are mixed with air and become airborne zinc oxide and other metal oxides. The airborne zinc oxide and other metal oxides are collected.