Leaching Lurgi

The endless-belt percolator (Wakeman, loc. cit.) is similar in principle, but the successive feed, solvent spray, drainage, and dumping stations are hnearly rather than circulany disposed. Examples are the de Smet belt extractor (uncompartmented) and the Lurgi frame belt (compartmented), the latter being a kind of linear equivalent of the Rotocel. Horizontal-belt vacuum filters, which resemble endless-belt extractors, are sometimes used for leaching. 

Oust Collection by Disposition of Dust Electrostatic Precipitator (Lurgi) Recycled to Zinc Plant Bag House Recycled to Sinter Machine Bag House Leaching / Solvent Extraction tor Zn Cd Recovery Bag Housa Recycled to Sinter Machine ESP (Lurgi) Recirculated to QSL-Converter... 

The Zincor process is based on the roast-leach-electrowinning process. The zinc sulphide concentrate is roasted in four Lurgi fiuo-solids roasters to produce zinc oxide and sulphur dioxide gas. The SO2 gas is fed to two Monsanto double absorption acid plants. 

The process for treating the baghouse dusts consists of leaching the dusts with a sulphuric acid solution, generating a lead and silver residue as a by-product, which is returned to the lead smelter, and a zinc sulphate solution, that is purified to remove Pb, Fe, Cd and As. Zinc extraction is carried out by a solvent extraction process based on Lurgi technology. The zinc-rich solution obtained in the solvent extraction plant is sent to the electrolytic zinc plant for zinc recovery and an ammonium sulphate and chloride salt is obtained fix>m the raffinate for agricultural applications. The plant has a capacity of 5,000 totmes Zn/year. 

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