| 摘要 |
<p>A foamed-glass granular material has a grain-size of between 0.2 and 3 mm between 106 and 107 gas cavities per cm3 of granular material and a bulk-weight of between 100 and 500 g/litre. The diameter of the largest gas cavity is substantially less than 0.1 mm. The gas cavities are mostly, or exclusively, closed cells of the same order of magnitude. The foamed-glass granular material may also contain up to 85% by weight of pumice, lava and/or tuff. The said material is produced by grinding the raw materials into a flour, mixing the said flour with an organic and/or inorganic expanding agent which releases gas under the action of heat, forming from this mixture a raw granular material having a grain diameter of between 0.1 and 1.5 mm, and heating this material in a suspension or vibration furnace, for between 5 and 180 seconds, at between 600 and 900.degree.C. The foamed-glass granular material thus obtained is removed from the furnace before the small gas cavities, initially produced during the expansion process) can combine to any great extent to form larger gas cavities.</p> |
