The effect of magnesium on the structure of calcium aluminosilicate glasses

Samples of cemented magnesium turnings and Magnox alloy, simulating wasteforms that require re-work, have been thermally treated to produce largely glassy calcium magnesium aluminosilicate products. X-ray diffraction shows the presence of a variety of crystalline phases (Mgx Al2–x O4 phases, åkermanite-gehlenite phases and merwinite), as well as diffuse scattering characteristic of glassy material. Structural investigations using Raman spectroscopy show that the products contain amorphous aluminosilicate networks, with changes in the Q2 and Q1 species in the network with increasing metal content. These investigations also suggest a high number of [AlO4]– tetrahedra are present in the network.