Abstract: | Based on the composition of float glass, the resistance of glass to water, in which a small amount of K2O (0-1.0 wt% ) was substituted for equivalent amount of Na2O, was investigated by means of glass grains testing. The components extracted from the glass and total alkalinities in extraction solution were determined by atomic absorption spectroscopy and neutralizing method, respectively. The composition of the glass was 14.4 K2O Na2O, 4.0MgO, 8.2CaO, 1.4Al2 O3, 72.0 SiO2, and the minimum extraction ratio of oxides (maximum durability) occurred at a K2 O/Na2O ratio of 0.051( by weight) due to the presence of the mixed-alkali effect. The relative extraction ratio of alkali oxides (R2O) was greater than that of alkaline earth oxides (RO) . By means of mixed-alkali effect and lowing relative contents of R2O in the glass, the resistance of float glass to water was improved and its mildew-proof ability was therefore increased. |