(19)

(11)

EP 0 486 612 A1

(12)

(43) Date of publication: 27.05.1992 Bulletin 1992/22 (21) Application number: 90913307.0 (22) Date of filing: 30.07.1990

(51) International Patent Classification (IPC):  C06B 47/ 00( . ) C06B 47/ 14( . ) (86) International application number: PCT/US1990/004261 (87) International publication number: WO 1991/001800 (21.02.1991 Gazette 1991/05)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB IT LI LU NL SE (30) Priority: 11.08.1989 US 19890393533 (71) Applicant: MINING SERVICES INTERNATIONAL CORPORATION Salt Lake City, UT 84107 (US)	(72) Inventors: LOWNDS, C. Mick Salt Lake City, UT 84108 (US) GROW, Steven, C. North Ogden, UT 84404 (US) (74) Representative: Johnstone, Helen Margaret  Urquhart-Dykes & Lord Tower House Merrion Way Leeds LS2 8PA Leeds LS2 8PA (GB)