Leaching and devitrification of lead, molybdenum and phosphorus oxide glasses

^1,3 Moulay Ismail University Meknes, Faculty of Science and Technology Er-Rachidia, Chemistry department, Morocco
² Moulay Ismail University Meknes, National School of Arts and Crafts, Laboratory of Engineering Sciences and Professions, Meknes, Morocco
⁴ Ibn Tofail University, Faculty of Sciences, Physics department, Kenitra, Morocco
⁵ Cadi Ayyad University, Faculty of Sciences Semlalia, LPCME, Morocco

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

Morocco has established a prominent industry focused on the transformation and development of its abundant phosphate deposits, valued for their diverse properties. Numerous physic-chemical studies focus on the leaching and devitrification of oxide glasses characterized by the composition yPbO-(1-y)[xMoO₃-(1-x)P₂O₅], with specific parameters of 0≤y≤0.3 and x values of 0.5 and 0.67. Measurements indicated that the addition of PbO in phosphate glasses, at concentrations from 0% to 30%, affects chemical durability. This was assessed across various solution pHs and dissolution times, utilizing an ammonium acetate solution and grain sizes between 300 to 500 urn, demonstrating the cross-linking effect of lead on the glass framework. A study indicates that the mass losses from the leaching of glasses occur linearly over time, regardless of their composition, and that glasses containing PbO exhibit increased durability. Studying the devitrification of elaborate glasses, this work presents X-ray diffraction analysis results for two glass families (x=0.67; 0.5). The analysis of the crystalline glass composition 0.3PbO-0.47MoO₃-0.23P₂O₅ indicates the formation of Pb(MoO₂)₂(PO₄)₂.