(19)

(11)

EP 0 500 708 A1

(12)

(43) Date of publication: 02.09.1992 Bulletin 1992/36 (21) Application number: 90917179.0 (22) Date of filing: 06.11.1990

(51) International Patent Classification (IPC):  B01D 53/ 32( . ) C01B 13/ 02( . ) (86) International application number: PCT/US1990/006423 (87) International publication number: WO 1991/006691 (16.05.1991 Gazette 1991/11)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB GR IT LI LU NL SE (30) Priority: 06.11.1989 US 19890432390 (71) Applicant: CERAMATEC, INC. Salt Lake City, UT 84119 (US)	(72) Inventors: JOSHI, Ashok, V. Salt Lake City, UT 84105 (US) NACHLAS, Jesse, A. Salt Lake City, UT 84105 (US) STUFFLE, Kevin Salt Lake City, UT 84115 (US) (74) Representative: Rees, David Christopher, et al  Kilburn & Strode 30 John Street London WC1N 2DD London WC1N 2DD (GB)