Improvement of mechanical and optical properties of Na2O–CaO–SiO2 glasses based on dune sand

Abstract

This work aims to discuss on the characterization of Algerian dune sand named Boussaâda sand (SB) and its suitability for glass industry. Based on chemical and mineralogical analyses of SB by XRF and XRD, quartz, kaolinite, calcium carbonates and albite are the main mineralogical phases found. However, Fe2O3 content is relatively low (<0.24wt%). Optical properties of the elaborated glass determined by UV-Visible Spectroscopy reveal that SB based glass (GB) presents better light transmission than industrial used sand (ST) based glass (GT). The CIE L*a*b* color measurements show that the sample is colorless. Knoop Hardness measurements indicate that GT is more hard than GB. Chemical durability tests reveal that in an acid solution, GB is more resistant, whereas it is more vulnerable in the presence of alkaline and HF solution. Furthermore, TiO2 additions in SB-based glass improve the clarity and transparency of the glasses (from L*=87.67 to L*=91.05 with 1wt% of TiO2). Thus, when TiO2 content increased, Knoop microhardness enhance (from 451 to 469 HK with 0.1wt% of TiO2). An increase in the glass chemical durability of the samples in acidic and alkaline solutions is noticed when trace amounts of TiO2 are added to the glass.