Phase Composition, Structure, and Hydrolytic Stability of Sodium-Aluminum(Iron) Phosphate Glass Containing Rare-Earth Oxides

Resumo

The phase composition, structure, elemental distribution, and hydrolytic stability of quench-hardened and tempered sodium-aluminum-phosphate (SAP) and sodium-aluminum(iron) phosphate (SAIP) glass materials containing 10 wt.% (above 100%) oxides of rare earth elements (REE) were studied. It is shown that all materials obtained by quench-hardening melts (except La-containing melts) were x-ray amorphous, while slowly cooled (tempered) melts partially or completely crystallized with different phases of orthophosphates being released. The rate of leaching of elements from tempered SAP glasses determined at 90°C is approximately one or two orders of magnitude higher than then for the quench-hardened glasses, and the leach rate of elements from quench-hardened SAIP glasses is lower than from quench-hardened SAP glasses.