Filter for holding and raising ground water

US6372135B1 · kind B1 · utility

Assignees

• Henkel Kommanditgesellschaft auf Aktien · DE
• Lausitzer Braunkohle · DE

Inventors

• Hans-Peter Kohlstadt · Velbert, DE
• Klaus Marten · Dormagen, DE
• Lothar Thiele · Langenfeld, DE
• Werner Fahle · Cottbus - Chóśebuz, DE
• Rainer Tost · Wendelstein, DE
• Annebärbel Tost · Cottbus - Chóśebuz, DE
• Peter Tost · Cottbus - Chóśebuz, DE
• Frank Tost · Cottbus - Chóśebuz, DE

Key dates

• Filing date: Nov 6, 1997
• Grant date: Apr 16, 2002
• Expiry date: Nov 6, 2017

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08K3/34
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

The invention relates to a filter in which dust-containing silica sand is held together by a polyurethane binder, the polyurethane binder containing an organotin compound with a molecular weight of more than 600 as catalyst and a mixture of highly dispersed silica and/or bentonites with a thickened aluminosilicate as modifier. The filter is particularly suitable for the production of drinking water from ground water in surface mining regions.