Karamanov, A.

Pelino, M.

Pisciella, P.

English

Pisciella P.

Karamanov A.

Pelino M.

University of Szeged

Acta Minera Iogica-Petrograph ica, Szeged, XL1, Supplementum B, 2000 VITRIFICATION OF JAROSITE WASTE FROM ZINC ELECTROLYTIC EXTRACTION PROCESS PISCIELLA. P.. KARAMANOV, A. & PELINO, M. (University of L'Aquila, L'Aquila, Italy) Wastes arising from primary raw materials refining and metal extraction plants are presently landfilled. Projects of re-utilisation as secondary raw materials have been pre-sented proposing interesting solutions to the environmental problems generated by waste disposal and providing a new source of raw materials. Jarosite is a by-product generat-ed in zinc hydrometallurgy during the separation of iron after the hot acid leaching of roasted sphalerite concentrate. The jarosite process is a simple and low cost technology but involves the production of a huge quantity of hazardous waste (0.4 t per ton ore). In this study, the possibility of reutilising jarosite as a secondary raw material by means of vitrification has been investigated. The wastes were characterised by XRF spectroscopy and the results showed the pres-ence of the elements Fe, S, Si, Zn and Pb. They were subjected to the TCLP (Toxic Characterization Leaching Procedure) by putting them in contact with distilled water for 24 h at constant pH 5 and the leachate was analysed by means of atomic adsorption. In the leachate, zinc (15.5 mg/1) and lead (4.0 mg/1) concentrations largely exceeded the European limits. Different batch compositions were prepared by mixing jarosite with silica-rich wastes such as granite mud and glass cullet. Fusion was carried out in corundum crucibles in an electric furnace in the 1400-1450 °C temperature range. Glass frit, glass-ceramic tiles and glass fibres were obtained. The materials were characterised in order to investigate their stability and the possibility of re-utilising them in the building industry. The results obtained highlighted the possibility of incorporating a consistent amount of wastes into glass form products. It has been possible to stabilise hazardous compo-nents in glass batches containing up to 50% of waste. The final glass easily passes the TCLP test. The jarosite glasses have characteristics such as density 2.8-3 g/cm3, thermal expansion 7 -8x10^ Kr1, and chemical durability in acid and basic media, comparable to that of commercial materials. The vitrification-recycling of wastes is a combined process that offers solutions to the environmental impact of zinc extraction activities and opens large opportunities for the valorisation of wastes. References PELINO, M. (1998). Interceram., 47 (1): 22. PISCIELLA, P., KARAMANOV, A. & PELINO, M. (1999). Global Symposium on Recycling, Waste Treatment and Clean Technology, San Sebastian, Spain. (1) 153 p. 56 

Vitrification of jarosite waste from zinc electrolytic extraction process

http://acta.bibl.u-szeged.hu/25063/1/mineralogica_041_suppl_b_056.pdf

Vitrification of jarosite waste from zinc electrolytic extraction process

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