Reproducible preparation of lithium tetraborate fused beads for XRF analysis of glass and mineral samples is of paramount importance for analytical repeatability. However, as with all glass melting processes, losses due to volatilisation must be taken into account and their effects are not negligible. Here the effects of fused bead melting time have been studied for four Certified Reference Materials (CRM’s: three feldspars, one silicate glass), in terms of their effects on analytical variability and volatilisation losses arising from fused bead preparation. At melting temperatures of 1065 °C, and for feldspar samples, fused bead melting times shorter than approximately 25 min generally gave rise to a greater deviation of the XRF-analysed composition from the certified composition. This variation might be due to incomplete fusion and/or fused bead inhomogeneity but further research is needed. In contrast, the shortest fused bead melting time for the silicate glass CRM gave an XRF-analysed composition closer to the certified values than longer melting times. This may suggest a faster rate of glass-in-glass dissolution and homogenization during fused bead preparation. For all samples, longer melting times gave rise to greater volatilisation losses (including sulphates and halides) during fusion. This was demonstrated by a linear relationship between SO3 mass loss and time1/2, as predicted by a simple diffusion-based model. Iodine volatilisation displays a more complex relationship, suggestive of diffusion plus additional mechanisms. This conclusion may have implications for vitrification of iodine-bearing radioactive wastes. Our research demonstrates that the nature of the sample material impacts on the most appropriate fusion times. For feldspars no less than ~25 min and no more than ~60 min of fusion at 1065 °C, using Li2B4O7 as the fusion medium and in the context of feldspar samples and the automatic fusion equipment used here, strikes an acceptable (albeit non-ideal) balance between the competing factors of fused bead quality, analytical consistency and mitigating volatilisation losses. Conversely, for the silicate glass sample, shorter fusion times of less than ~30 min under the same conditions provided more accurate analyses whilst limiting volatile losses.

The energy intensive and CO2-generating nature of commercial mineral wool and glass production necessitates advances and changes in materials and processes. The derivation of raw materials from waste products arising from biomass energy generation offers the possibility of a two-fold environmental benefit: partial replacement of carbonate raw minerals in production, leading to lower CO2 release during melting; and the utilisation and valorisation of byproducts which may otherwise be sent to landfill. Glass samples with a basaltic mineral wool composition were produced with additions to the raw materials of 0, 1, 5 and 10 wt% of a fly ash and a bottom ash arising from biomass combustion. The resulting glasses were analysed by x-ray fluorescence, x-ray diffraction, dilatometry, 57Fe Mössbauer and Raman spectroscopies, and their densities, molar volumes and viscosity–temperature profiles were calculated and compared against benchmark glass samples. All biomass ash-containing glasses were closely similar in both composition and properties to the benchmark glass, with up to 10 wt% ash additions to the raw materials. In addition, the use of the biomass fly ash led to a reduction in batch CO2 content estimated to be 1·5 kg CO2 per tonne of batch for each 1 wt% addition. These initial results provide evidence supporting the further development of these ash materials as potential value-added raw materials for mineral wool manufacture.

We report a new series of DP Sr2(Fe1−xNix)TeO6, which have different transition metal Fe and Ni on B sites, providing an opportunity to investigate their effect on crystal structure, vibrational, optical and magnetic properties.

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