| 摘要 |
A process of manufacturing vitreous beads is disclosed in which feedstock particles of a glass-former composition containing less than 15% by dry weight of sodium and potassium calculated as their respective oxides and containing chemically bound water, are fed through a heating zone in which the particles are vitrified and spherulized and the resulting vitreous beads are cooled. The vitrifiable oxide forming elements of said glass-former composition may be chemically interlinked, and the feedstock may be prepared as a silica-based gel or precipitate having a composition suitable for vitrification into a glass of a desired composition which by virtue of its low alkali content is resistant to hydrolytic attack. By control of the cellulating agent content (bound water and optionally a gas evolving salt radical such as nitrate or sulphate) of the feedstock, and its granulometry, the relative proportions of solid and hollow beads which will be produced in a given spherulizing run can be controlled. |
