A method for producing metal zinc by liquid/liquid extraction, comprising leaching of a zinc-bearing solid raw material containing antimony with a slightly acid aqueous solution, at a pH value maintained above 3 and less than or equal to 5, with formation of a suspension, drawing-off from the suspension of an aqueous phase containing zinc in solution to be subject to the extraction, additional leaching of the remaining suspension with an acid aqueous solution, at a pH value maintained below 3.5 and greater than or equal to 1, with formation of a pulp, introduction of a neutralizing agent in this pulp with coprecipitation of antimony and other impurities and separation from this neutralized pulp of a zinc-bearing aqueous solution which is recycled to the step for leaching the zinc-bearing solid raw material.

A method for producing metal zinc by liquid/liquid extraction, comprising leaching of a zinc-bearing solid raw material containing antimony with a slightly acid aqueous solution, at a pH value maintained above 3 and less than or equal to 5, with formation of a suspension, drawing-off from the suspension of an aqueous phase containing zinc in solution to be subject to the extraction, additional leaching of the remaining suspension with an acid aqueous solution, at a pH value maintained below 3.5 and greater than or equal to 1, with formation of a pulp, introduction of a neutralizing agent in this pulp with coprecipitation of antimony and other impurities and separation from this neutralized pulp of a zinc-bearing aqueous solution which is recycled to the step for leaching the zinc-bearing solid raw material.

A process is described for recovering a non-ferrous metal from a first solid residue comprising iron. In this process, the first solid residue is mixed with a second solid residue including sulphur, thereby obtaining a particulate mixture. The particulate mixture is subjected to a roasting step at a temperature of at least 650° C. to obtain a roasted mixture, and the roasted mixture is subjected to leaching in a liquid at a pH of at least 5.5 to obtain a solution enriched with the non-ferrous metal.

A process is described for recovering a non-ferrous metal from a first solid residue comprising iron. In this process, the first solid residue is mixed with a second solid residue including sulphur, thereby obtaining a particulate mixture. The particulate mixture is subjected to a roasting step at a temperature of at least 650° C. to obtain a roasted mixture, and the roasted mixture is subjected to leaching in a liquid at a pH of at least 5.5 to obtain a solution enriched with the non-ferrous metal.

[Object] To provide a method for processing steelmaking dust, a method for producing zinc, and a method for producing an iron- and steelmaking raw material, which are more advantageous than the Waelz method in terms of energy and economy.

[Solving Means] A method for processing steelmaking dust according to an embodiment of the present invention includes: adding a calcium compound containing Ca to steelmaking dust containing zinc, the number of moles of Ca being equivalent to or more than the number of moles of Fe in the steelmaking dust; and heating and reducing, in a furnace, the steelmaking dust to which the calcium compound has been added. A ratio of the number of moles of Ca in the calcium compound to the number of moles of Fe in the steelmaking dust is adjusted to be not less than 1.3 and not more than 1.5.

[Object] To provide a method for processing steelmaking dust, a method for producing zinc, and a method for producing an iron- and steelmaking raw material, which are more advantageous than the Waelz method in terms of energy and economy.

[Solving Means] A method for processing steelmaking dust according to an embodiment of the present invention includes: adding a calcium compound containing Ca to steelmaking dust containing zinc, the number of moles of Ca being equivalent to or more than the number of moles of Fe in the steelmaking dust; and heating and reducing, in a furnace, the steelmaking dust to which the calcium compound has been added. A ratio of the number of moles of Ca in the calcium compound to the number of moles of Fe in the steelmaking dust is adjusted to be not less than 1.3 and not more than 1.5.

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 rotation-suspension smelting method, in which a powdered sulfide concentrate and an oxygen-containing gas are sprayed into a high-temperature reaction tower. The oxygen-containing gas is divided into two parts: the second oxygen-containing gas is sprayed in the form of an annular direct flow into the reaction tower and forms a bell-shaped wind curtain; and the first oxygen-containing gas is transformed into a rotation-jet and jetted into the center of the wind curtain. In the space between the gas flows, the concentrate entering in a direction deviated towards the center is drawn in the rotation-jet, and a high-temperature off-gas is sucked in, forming a gas-particle mixed two-phase rotation-jet. The sulfide concentrate is ignited, at the same time, a melt containing matte (or metal) and slag is formed; and the matte (or metal) is separated from the slag at the bottom of the reaction tower, completing the metallurgical process.

A rotation-suspension smelting method, in which a powdered sulfide concentrate and an oxygen-containing gas are sprayed into a high-temperature reaction tower. The oxygen-containing gas is divided into two parts: the second oxygen-containing gas is sprayed in the form of an annular direct flow into the reaction tower and forms a bell-shaped wind curtain; and the first oxygen-containing gas is transformed into a rotation-jet and jetted into the center of the wind curtain. In the space between the gas flows, the concentrate entering in a direction deviated towards the center is drawn in the rotation-jet, and a high-temperature off-gas is sucked in, forming a gas-particle mixed two-phase rotation-jet. The sulfide concentrate is ignited, at the same time, a melt containing matte (or metal) and slag is formed; and the matte (or metal) is separated from the slag at the bottom of the reaction tower, completing the metallurgical process.