Jarosite (JW) and goethite (GOW) are iron rich hazardous wastes resulting from the hydrometallurgical process used in producing zinc metal. Granite scraps and mud (granite wastes, GW) are generated from the caving and sawing of the blocks. The aim of the study, supported by EU Commission project and BRE2-CT94-1018, is to recycle the hydrometallurgy wastes - in combination with GW and other residues - to obtain a composition suitable to be vitrified and then crystallised to obtain glass-ceramic materials. Several glass-compositions were prepared by mixing JW or GOW, GW and glass-cullet. with the following compositional ranges 40-70 percent for JW, or GOW, 20-40 percent for GW and 10-40percent for glass-cullet. The batches were melted in a 1 ton/day pilot plant by using a gas furnace at 1450 deg C. The glass frit was utilised "as it is" or subjected to nucleation and crystallisation thermal treatment in order to obtain a GC materials. The properties of the glass and glass-ceramics were tailored for the exploitation of the products in the building industry, in form of glass fibres for insulation, paving tiles, wall covering panels, glazes for the cermaic industry.
展开▼
