Glass and glass-ceramic materials obtained from zinc-hydrometallurgy hazardous wastes

Jarosite (JW) and geothite wastes (GOW) are iron rich hazardous wastes that result from the hydrometallurgical process used in producing zinc metal. Due to the presence of heavy metals in the composition ( mainly Zn and Pb) and the large amount produced yearly in the E.U., the disposal of the waste is generating serious social and economical difficulties. Granite scraps and mud (granite wastes, GW) are generated from the caving and sawing of the blocks. Their disposal also represents a consistent environmental impact. The aim of the study, supported by EU Commission projects MA2R-CT90-0007 and BRE2-CT94-1018, is to recycle the Zinc-hydrometallurgical wastes - in combination with GW and other residues - to obtain glasses and then crystallise to obtain glass-ceramic materials. Several glass-compositions were prepared by mixing as an example JW, GW and glass-culler with the following compositional ranges 40-70 % for JW, 20-40 % for GW and 10-40% for glass-culler. The properties of the glass-ceramics were tailored for the exploitation of the products in the building industry, in the form of paving tiles, wall covering panels or glass fibers for insulation.