Porous silica granule, method for producing the same, and method for producing synthetic quartz glass powder using the porous silica granule
    1.
    发明授权
    Porous silica granule, method for producing the same, and method for producing synthetic quartz glass powder using the porous silica granule 有权
    多孔二氧化硅颗粒,其制造方法以及使用多孔二氧化硅颗粒制造合成石英玻璃粉末的方法

    公开(公告)号:US06849242B1

    公开(公告)日:2005-02-01

    申请号:US09672438

    申请日:2000-09-28

    摘要: The granule consists of individual granules approximately spherical in shape, having a pore volume of 0.5 cm3, a mean diameter of pores of 50 nm or less, a specific surface area of 100 m2/g or less, and a bulk density of 0.7 g/cm3 or higher. It is produced by dispersing a fumed silica obtained by hydrolysis of a silicon compound into pure water to obtain a slurry, and drying the slurry. The granule is used for producing high purity synthetic quartz glass powder. The method further comprises: a first heat treatment under an oxygen-containing atmosphere, a second heat treatment in a temperature range of from 600 to 1100° C., and a third heat treatment in a temperature range of from 1100 to 1300° C. under an atmosphere containing hydrogen chloride; and a step of densification comprising calcining the product at a temperature not higher than 1500° C. under vacuum or in an atmosphere of gaseous hydrogen or gaseous helium. To calcine the powder without causing fusion adhesion of the particles, bubbling fluidization of said porous silica granule is conducted by supplying gaseous helium and calcining thereof in a temperature range of from 1000 to 1600° C.

    摘要翻译: 颗粒由近似球形的单个颗粒组成,孔体积为0.5cm 3,孔的平均直径为50nm以下,比表面积为100m 2 / g以下, 堆积密度为0.7g / cm 3以上。 通过将通过硅化合物的水解获得的热解法二氧化硅分散在纯水中得到浆料并干燥浆料而制备。 该颗粒用于生产高纯度合成石英玻璃粉末。 该方法还包括:在含氧气氛下进行第一次热处理,在600〜1100℃的温度范围进行第二次热处理,在1100〜1300℃的温度范围进行第三次热处理。 在含有氯化氢的气氛下; 以及致密化步骤,包括在真空下或在气态氢气或气态氦气氛中,在不高于1500℃的温度下煅烧产品。 为了煅烧粉末而不引起颗粒的熔融粘附,所述多孔二氧化硅颗粒的鼓泡流化是通过在1000至1600℃的温度范围内提供气态氦和煅烧来进行的。

    Method for the manufacture of SiO.sub.2 granular material
    2.
    发明授权
    Method for the manufacture of SiO.sub.2 granular material 失效
    制备SiO2颗粒材料的方法

    公开(公告)号:US5979186A

    公开(公告)日:1999-11-09

    申请号:US112921

    申请日:1998-07-09

    CPC分类号: C03B19/1065 C03C1/026

    摘要: A method is provided for the manufacture of SiO.sub.2 granular material. Silicic acid is dispersed in a liquid to form a dispersion. The dispersion is stirred in a stirring tank with formation of a homogeneous liquid phase. The homogeneous liquid phase is maintained by stirring at a substantially constant rate until the granular mass develops, when the solids content of the dispersion is within the range of 65 to 80 weight percent. Moisture is gradually extracted to form a granular mass which is dried and sintered.

    摘要翻译: 提供了一种制备SiO 2颗粒材料的方法。 将硅酸分散在液体中以形成分散体。 将分散体在形成均相液相的搅拌槽中搅拌。 当分散体的固体含量在65至80重量%的范围内时,通过以基本上恒定的速率搅拌直至粒状体形成均匀的液相来维持。 水分逐渐提取形成干燥和烧结的颗粒状物质。