Abstract
The surface tension of the sodium silicate-metal oxide system was measured by a sessile drop method in nitrogen flow. The sodium silicate consisted of 44.5 mol%Na2O and 55.5 mol%SiO2, and metal oxide (CaO, MgO, MnO, and Al2O3) was added by 5 mol%, 10 mol%, 15 mol% to sodium silicate. Generally, the surface tension of sodium silicate increases with the content of additional metal oxide. When sulfur was added to the sodium silicate, its surface tension decreased. The temperature coefficient of the surface tension of sodium silicate was negative, while that of the silicate containing Al2O3 was positive. The density of liquid sodium silicate was calculated based on the dimensions of the sessile drops of silicate.
