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The waste vitrification of abandoned open sky vermiculite deposits has been considered by combining with a natural phosphate mineral residue. Several batches haven been designed from the composition system: Li 2 O-MgO-Al 2 O 3 -P 2 O 5 -SiO 2 including some Fe 2 O 3 and Fluoride. The resulting glasses are transparent and smooth green coloured, giving rise after TTT treatments to several opal, opaque glass-ceramics with iridescent surface. Full characterization has been carried out by XRD and electron microscopy with EDS, as well as by XPS spectroscopies, concluding that the main crystalline phases formed were α-cordierite and β-spodumene. The surface of these glass-ceramics from vermiculite-amblygonite is enriched in Fe 2 O 3 . Compared to the parent glasses, the final glass-ceramics exhibited and improvement in fracture toughness. [ABSTRACT FROM AUTHOR]

The effect of iron oxide content on the crystallisation of a zirconium-based glass-ceramic glaze was investigated using a glass-ceramic “white of zirconium” frit and a granite waste glass. Measurements by X-ray diffraction (XRD) combined with scanning electron microscopy (SEM) and EDX microanalysis showed that Fe2O3 gives rise to the crystallisation of an iron-zinc ferrite, which is acting as nucleating agent of feather-like crystals of pyroxene while granite frit enhances the partial dissolution of zircon into the glassy phase, which is sharply increased for granite frit additions greater than 50%. [Copyright &y& Elsevier]

• The thermal plasma treatment for the hospital incineration fly ash utilization. • Chemical stabilization studies by leachability tests in raw materials and ceramics. • The physical features comparison of vitrificates in the hardness tests. The thermal plasma treatment is an effective method which can be used to convert hazardous waste into less toxic or inert glassy products. The aim of this paper is to show the experimental use of a thermal plasma treatment process to transform the hospital incineration fly ash into glassy products (vitrificates) that can be stored on the land without harmful environmental effects or sintered for producing with some additives coloured tiles useful as construction materials. The aims were achieved by: (i) optimization of temperature and energy used adjusting the process to minimum cost and (ii) stabilization of vitrificates with different compositions of waste mixtures. The chemical stabilization of final products was examined by heavy metals leachability tests. Hardness measurements were done to verify the physical stabilization of vitrificates. Also, it has been tested if the reinforcement and coloration of raw material by various pigments as well as the chemical compounds affect the stability of the final products. It was seen that chemical composition of raw materials influenced the chemical and physical properties of the vitrificates and decided about their internal structures. [ABSTRACT FROM AUTHOR]