| 摘要 |
<p>The invention relates specially to a mixture of fused vitreous silica particles and grains produced by dry mixing: (i) A fused vitreous silica fraction of moderately coarse particle size, at least 80% by weight of the grains of which are between 40 mu m and 1 mm; (ii) a fused vitreous silica fraction of fine particle size, at least 95% by weight of the grains of which are less than 40 mu m, the said grains (ii) having a BET specific surface of 6 to 9 m<2>/g and a median diameter by sedigraphy of 5 to 6 mu m; (iii) substantially spherical particles of fumed silica, and (iv), optionally, at least one fused vitreous silica fraction with a coarser particle size than the fraction (i), the constituents (i) to (iv) being used in the following proportions by weight: (i) 15-70%, (ii) 15-55%, (iii) 3-15% and (iv) 0-52%. This mixture is useful for the production of articles made of sintered vitreous silica. <IMAGE></p> |
