Storage of toxic heavy metals in phosphate glasses: physical and water durability properties

• Published in: Materials letters Vol. 57; no. 4; pp. 894 - 898
• Main Authors: El Hadrami, A, Aouad, H, Mesnaoui, M, Maazaz, A, Videau, J.J
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 2002; Elsevier
• Subjects: Applied sciences; Chemical Sciences; Exact sciences and technology; General treatment and storage processes; Heavy toxic metals; Material chemistry; Phosphate glasses; Physical properties; Pollution; Wastes; Water durability; Phosphate glasses; Water durability; Physical properties; Heavy toxic metals; Aluminium oxide; Cadmium; Network structure; Waste storage; Chemical stability; Immobilization; Durability; Phosphate glass; Structure composition relationship; Zinc; Heavy metal; Ion substitution; Lead; Phosphorus oxides
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/S0167-577X(02)00891-1

Phosphate glasses of composition (100− y)[50 P 2O 5–15 ZnO–(35− x) PbO– x CdO]– yAl 2O 3 have been prepared and studied. In the alumina-free glasses ( y=0), the effect of CdO substitution for PbO involves a strengthening of the glass network with a maximum of the aqueous durability for x values close to 20. For x=20, the addition of Al 2O 3 in the composition range 0≤ y≤8 leads to a progressive increase of the phosphate network reticulation. For y>4, an unexpected change in the properties is observed, which probably results from a cationic rearrangement in the glass structure. For y=8, the chemical durability is equivalent to that of window glass. Such glasses are potential candidates for the storage of toxic heavy metals.