| 摘要 |
A method of producing dense, free-flowing alkali metal silicate-based particles which, when sufficiently heated, will form lightweight particles of a spumiform nature which may be employed as thermal or acoustical insulation or as a lightweight filler for gypsum or cement or for numerous other purposes. The method comprises premixing a liquid alkali metal silicate with selected fillers and/or insolubilizers, adjusting the temperature and solids content of the mixture until it passes into a dilatant gel state which will fracture when extended at a rate of between about 3 and 95 cm/minute, and subsequently extruding or pelletizing the gel at this temperature to form particles which are conditioned in an air stream for at least one second and then dried to a moisture level of between about 5 and 30%. These particles or pellets serve as a stable intermediate which can be expanded to form lightweight spumiform particles by further heating at a later time or at a remote location.
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