Abstract:
Chelyabinsk Zinc Plant developed the technology of processing of zinc-, lead- and tin-containing copper industry dusts, including the following stages:<br />-pyrometallurgical stage – calcinations with an addition of sulphidizer, flux and reducing agent to the product, where lead is removed from the product with a transfer in processed sublimates, while zinc and tin stay in cinder;<br />- hydrometallurgical stage – high-temperature leaching of cinder, where zinc, iron, copper etc. are extracted in solution with obtaining of tin-concentrating solid residue. <br />There is considered the hydrometallurgical stage of obtaining of tin-containing concentrate from cinder with low content of lead (less than 1%). <br />There is shown the low extraction of zinc in solution and absence of selective separation of tin and lead with acid sulfuric-acid dust leaching without application of pyrometallurgical stage. <br />Three-stage leaching (similar to the technology of hydrometallurgical processing of Waelz-oxides, existing in Chelyabinsk Zinc Plant) and one-stage high-temperature leaching were researched for obtained cinder. Three-stage product leaching is low-efficient, because it requires a lot of equipment and does not provide the required concentration of tin in solid residue. <br />About 98% of zinc, contained in cinder, more than 95% or copper and iron is transferred in solution during the high-temperature product leaching by waste zinc electrolyte with addition of sulfuric acid (t= 80-900C, the concentration of H2SO4 is 160-170g/dm3). Obtained solution is required for application in a technological cycle of the zinc plant. The solid residue contains 14-21% of tin, which allows to use it at tin enterprises. <br />Keywords: copper industry dusts, cinder, pulp, hydrometallurgical processing, selective leaching, zinc, tin, lead.
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