| 摘要 |
1,140,896. Vitreous granules; removing oil pollution; ceramic compositions. WASAGCHEMIE A.-G. 11 March, 1966 [8 April, 1965; 16 Oct., 1965; 6 Dec., 1965], No. 10911/66. Headings C1C, C1J and C1M. [Also in Divisions B3 and C3] A granular material is formed by (a) forming a solution of 0.02-0À7 parts by weight of fibrous siliceous material in one part by weight of an aqueous alkali silicate, (b) removing water until a solid mass is formed and granulating, (c) providing the granules with a surface layer consisting of a high-melting oxide or substance capable of forming a high-melting oxide on heating, and (d) heating to 600‹-1000‹ C. The fibrous material may be glass, rock, or basalt wool. Porosity-increasing additives, e.g. sugar, glycerin, sulphides, oxides, hydroxides, or carbonates, or pigments may be included in the initial mixture. The surface layer may be provided by contact with an aqueous suspension of lime, chalk, zinc oxide, alumina, or iron oxide. The material may be moulded after addition of a binder, e.g. polyester or epoxy resin, gypsum, Portland or other cement, or lime, dry or moist oxidic masses, e.g. raw brick, fire clay, or tiling materials, or clay, kieselguhr, kaolin, clay mixed with TiO 2 , felspar, quartz or masses containing magnesite or corundum, e.g. 5-90% by weight based on the granular product. When ceramic masses containing the granular material are fired, cavities are formed where the granules were present, the cavities being enclosed by a thin skin of vitreous material. The granules may be coated or cast with a molten metal e.g. Al. The porous material may be present as partial or zoned layers-thus a tile may have a compact ceramic surface layer backed by a porous ceramic layer. After treatment with a hydrophobing agent, e.g. a metal soap or a silicone oil, the granular particles may be floated on water which carries a film of oil; they absorb the oil and continue to float, and may be easily removed, leaving the water oil-free. |
