Method and apparatus for treating silica granules using porous graphite crucible
    4.
    发明授权
    Method and apparatus for treating silica granules using porous graphite crucible 有权
    使用多孔石墨坩埚处理二氧化硅颗粒的方法和设备

    公开(公告)号:US06319550B1

    公开(公告)日:2001-11-20

    申请号:US09358817

    申请日:1999-07-22

    IPC分类号: B05D700

    摘要: Silica granules made up of mutually agglomerated silica soot particles are treated by placing the granules in a crucible inside a furnace which contains an inert gas mixed with a chlorine-containing compound and in which the temperature lies in the range 1000° C. to 1500° C. According to the invention, a crucible is used that is made of porous graphite firstly to increase the surface area of the crucible through which the chlorine-containing compound diffuses. This gives rise to faster exchange between the granules and the gas for given partial pressure of the chlorine-containing compound, thereby improving purification. Secondly, the difference between the chemical natures of the silicas and the crucible make the two materials inert relative to each other so that the granules do not adhere to the walls of the crucible, thereby making it possible to recover the granules without having to apply any mechanical operation that might contaminate them.

    摘要翻译: 将由相互团聚的二氧化硅烟灰颗粒构成的二氧化硅颗粒通过将颗粒放入含有与含氯化合物混合的惰性气体的炉内的坩埚中进行处理,其中温度在1000℃至1500℃的范围内 C.根据本发明,首先使用由多孔石墨制成的坩埚以增加含氯化合物通过其扩散的坩埚的表面积。 这导致颗粒和气体之间的交换更快,以使给定的含氯化合物分压,从而改进纯化。 其次,二氧化硅和坩埚的化学性质之间的差异使得两种材料相对于彼此是惰性的,使得颗粒不粘附到坩埚的壁上,从而使得可以回收颗粒而不必施加任何 机械操作可能会污染它们。

    Method of manufacturing a silica powder
    5.
    发明授权
    Method of manufacturing a silica powder 失效
    二氧化硅粉末的制造方法

    公开(公告)号:US6071487A

    公开(公告)日:2000-06-06

    申请号:US116337

    申请日:1998-07-16

    摘要: In the method, a suspension of silica particles in water is provided, the suspension is gelled, the resulting gel is dried under microwaves, the dried gel is fractioned into silica granules having a diameter lying in the range 10 .mu.m to 1000 .mu.m, having an apparent density of about 0.5 g/cm.sup.3 to 0.6 g/cm.sup.3, and a porosity of less than 20%, and the granules are screened in the range 100 .mu.m to 500 .mu.m. The suspension in water of silica particles is made by mixing silica soots having a size of less than 0.1 .mu.m and silica grains having a size greater than 1 .mu.m. Its maximum concentration in total weight is greater than that of a suspension of synthetic soots on their own, thereby making it possible to increase the production capacity of the method. Advantageously, the out-of-range granules rejected by the screening are recycled as silica grains for the aqueous suspension, thereby making it possible to increase the accumulated production efficiency of the method.

    摘要翻译: 在该方法中,提供二氧化硅颗粒在水中的悬浮液,悬浮液凝胶化,得到的凝胶在微波下干燥,将干燥的凝胶分级成直径在10〜1000μm的二氧化硅颗粒, 具有约0.5g / cm 3至0.6g / cm 3的表观密度和小于20%的孔隙率,并且将颗粒筛选在100μm至500μm的范围内。 二氧化硅颗粒的水悬浮液通过混合尺寸小于0.1μm的二氧化硅烟炱和尺寸大于1μm的二氧化硅颗粒来制备。 其总重量的最大浓度本身大于合成​​烟灰的悬浮液的最大浓度,从而可以提高该方法的生产能力。 有利地,通过筛选而排除的超出范围的颗粒作为水性悬浮液的二氧化硅颗粒再循环,从而可以提高该方法的累积生产效率。