Process of using and products from fume amorphous silica particulates

US4297309A · kind A · utility

Inventor

• John W. North · Tucker, US

Key dates

• Filing date: Jun 25, 1980
• Grant date: Oct 27, 1981
• Expiry date: Jun 25, 2000

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02W30/91
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

Amorphous silica particulates, known as fume silica, which are generally spherical and of small particle sizes, are recovered from the stack gases issuing from an electric furnace producing silicon metal by the reduction of silica with carbon, and these fume silica particles are mixed with up to 40% water to produce a fume amorphous silica green product which is a plastic which may be compacted, such as being extruded, to produce batts or pellets or other shapes. The batts or pellets are sealed in plastic film or in cans and shipped or stored. The batts or pellets are subsequently shaped to prescribed shapes under pressure, dried and, at times, fired. The particulate amorphous silica and water material is, at times, compacted, dried and then shipped or stored. Such dried material is crushed and partially pulverized either before shipment or at the point of use and reconstituted by the addition of water. The fume silica is also mixed with water and a consumable filler or foaming agent and fired to produce a cellular product. The various products are machinable both before and after firing. A mixture of the fume silica and water does not settle out on standing or vibrating and is com…