GB504883A - Method of making filaments of pure silica, particularly quartz - Google Patents

Abstract

504,883. Making filaments of silica. SKAUPY, F., and WEISSENBERG. G. Aug. 16, 1938, Nos. 24126 and 24127. Convention dates, Aug. 19, 1937 and Aug. 1, 1938. [Class 56] [Also in Group III] A method of making filaments of silica consists in forming them from a silica compound which can be spun at a lower temperature than silica, and then freeing them from compounds other than silica by treatment with acid, and an acid salt, or other suitable reagents. An alkali-metal silicate, such as waterglass, may be used as the initial material, and this may be fused and drawn into filaments by the methods used in making glass wool. Alternatively, the waterglass may be dissolved in water or dilute alcohol and the solution treated with carbonic acid or other weak acid to precipitate part of the silica in the colloidal condition. If desired, the solution may then be centrifuged to separate a portion richer in silica, and this portion is spun into filaments. The material may be spun directly into an acid coagulating bath where it is converted immediately into filaments of silica. The fused material may be treated similarly. The filaments may be collected, however, and subsequently treated with dilute acids, or with gaseous hydrochloric acid or chlorine, to remove the basic constituents. Finally the filaments may be vitrified by passing them rapidly through a gas flame or an electrically heated zone. Colouring matter may be added to'the material before spinning.