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Hydrometallurgical treatment of non-sulfide zinc ore for precipitation of zinc oxide nanoparticles

Abdel-Aal E.-S. A., Rashad M. M., El-Shazly A. N., Ibrahim I. A., El-Shahat M. F.

Physicochemical Problems of Mineral Processing

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2016

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Vol. 52, iss. 2

729--737

EN

Acid leaching of Egyptian zinc ore from the Um Gheig area was carried out with sulfuric acid. This study determines the optimum conditions for dissolution of non-sulfide zinc ore. The optimum conditions are 25% -74m particle size, 45 °C temperature, 2 h leaching time, 1.1 stoichiometric molar ratio of H2SO4 to Zn, 1:3 solid/liquid ratio. The maximum filtration rate is 1.6 Mg Zn•m-2•day-1at pressure difference of 0.80 bar. The zinc recovery is about 90%. As the zinc ore contains zinc silicate, some additives were tested to enhance filtration and prevent formation of silica gel. To increase the added value of the product, zinc oxide was precipitated by a co-precipitation method in a nanosize powder with average particle size ~ 20 nm. Photocatalytic degradation of methylene blue dye under UV light using ZnO nanopowders produced at different conditions was investigated. Photocatalytic efficiency with methylene blue (MB) concentration was reduced as much as 85% in 240 min with the produced nanoparticles.

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An innovative technology for recovery of zinc, lead and silver from zinc leaching residue

Zheng Y.-X., Lv J.-F., Liu W., Qin W.-Q., Wen S.-M.

Physicochemical Problems of Mineral Processing

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2016

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Vol. 52, iss. 2

943--954

EN

Zinc leaching residue is a good source of zinc and has a great potential to be utilized. However, it is very difficult to recover lead, zinc and silver from the residue by traditional technologies. In this study, a new technology based on conversions of PbSO4 and ZnSO4 in the residue to their respective sulfides by reduction roasting with coal powder followed by a flotation treatment was developed. The effects of roasting temperature, coal dosage, reaction time and pyrite dosage were investigated at a laboratory scale. The results showed that the conversion extent of PbSO4 and ZnSO4 under the optimal experimental conditions was 71.89 and 69.76%, respectively. A flotation concentrate containing 39.13% Zn, 6.93% Pb and 973.54 g/Mg Ag was obtained from the treated material, and the recovery of Zn, Pb and Ag was 48.38, 68.23 and 77.41%, respectively. The tailing containing ZnFe2O4 or Fe3O4 could be either stockpiled or further disposed.

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Utilization of metallic wastes from the zinc sulfate production

Jarosiński A.

Polish Journal of Chemical Technology

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2004

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Vol. 6, nr 3

21-24

EN

In the work the possibility of copper materials processing derived from the production of zinc salts is presented. The described results of the tests on the basic processes used in the procedure, consist of three steps: leaching by ammonia and ammonium chloride, the decomposition of the copper ammine complex and the precipitation of the copper oxide and the ammonia recovery. The solution after leaching (100 - 130g Cu/dm3) was dropped into the stirred sodium hydroxide solution (200g/dm3) and copper(II) hydroxide was precipitated. It was found that the efficiency of the copper removal from the solution, depended on the temperature. At the solution temperatures, higher than 90°C, the yield of the process was near 100%. The final product, CuO, was achieved by the way of calcinations and its purity was about 99,9%. The product is suitable for the fodder addition and mineral fertilizer. The process was tested on the laboratory scale, as well as in the pilot plant.