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AssigneeMetso Metals Oy
InventorsJochen GÜNTNER, Maciej WROBEL, Dr.-Ing. Jörg HAMMERSCHMIDT, Eberhard SCHMIDT, Sebastian HIRSCH
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A process and its relating plant for recycling zinc oxide residues. Thereby, zinc oxide residues are granulated to particles with a size of d80 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 d80 100 μm, preferably below d80 75 μm 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.
-17. (canceled)
A process for recycling zinc oxide residues, wherein the zinc oxide residues are granulated to particles with a size of d80 between 0.3 and 5 mm and wherein these particles are fed into a roaster where they are thermally treated at a temperature in the range of 500 and 1.200 C in a fluidized bed to form a calcine, wherein sulfuric acid is admixed to the zinc oxide residues previous and/or during granulating and the granulating is done batch-wise while the roasting is a continuous process, wherein the zinc oxide residues are dusts coming from an electric arc furnace and/or from a Waelz process and/or that the zinc oxide residues are coming from melting and casting of zinc and/or zinc oxide and be crushed to a particle size below d80 100 μm before being granulated.
A plant for recycling zinc oxide residues, featuring at least one granulator, wherein the zinc oxide residues are granulated to particles with a size of d80 between 0.3 and 5 mm and a roaster, being designed as a fluidized bed reactor, wherein the particles are thermally treated at a temperature in the range of 500 and 1.200 C in a fluidized bed to form a calcine, and means for admixing sulfuric acid to the zinc oxide residues previous and/or during granulating and at least one bin for particles from the granulator are foreseen for a continuous feed into the fluidized bed reactor from a batch-wise operated granulator, wherein at least one apparatus as source for the zinc oxide residues which is an electric arc furnace, a Waelz kiln and/or an apparatus designed to melt and cast zinc and/or zinc oxide.
Dependencies are inferred from the claim text.