ENERGY EFFICIENT SODA LIME SILICATE GLASS COMPOSITIONS USING BORAX PENTAHYDRATE

摘要

The invention is directed to energy efficient soda lime silicate glass compositions using borax pentahydrate. The invented glasses have the compositions in the ranges: B2O3 = 7.19-51.74 wt.%, SiO2 = 22.68-74.62 wt.%, Na2O = 13.0-23.5 wt.%, CaO = 0.0-10.5 wt.%, K2O = 0.03-0.3 wt.%, Al2O3 = 0.15-1.3 wt.%, MgO = 0.43-4.0 wt.%, and Fe2O3+TiO2 = 0.05-0.12 wt.%. The evaluated properties of the glasses have revealed that these invented glasses are suitable for manufa turing improved quality container glasses, float glasses and glasses for ophthalmic lens blanks as well. The addition of borax pentahydrate originated B2O3 at its optimum level (28.5 - 30.3 wt.% B2O3) is found to reduce the glass melting temperature by 150-200°C. This lowering of glass melting temperature substantially saves energy and reduces the production cost; hence the compositions are energy efficient and cost effectives. It eliminates the use of soda ash and limestone, so it reduces the carbon dioxide (CO2) emission and thereby global warming; thus these compositions are environmentally friendly as well.