(19)

(11)

EP 0 335 922 A1

(12)

(43) Date of publication: 11.10.1989 Bulletin 1989/41 (21) Application number: 88907535.0 (22) Date of filing: 18.08.1988

(51) International Patent Classification (IPC):  B07B 13/ 11( . ) (86) International application number: PCT/US1988/002814 (87) International publication number: WO 1989/002320 (23.03.1989 Gazette 1989/07)

(84) Designated Contracting States: FR IT (30) Priority: 17.09.1987 US 19870097877 (71) Applicant: CYPRUS INDUSTRIAL MINERALS COMPANY Englewood, CO 80155 (US)	(72) Inventors: NICHOLS, Carl, W. Littleton, CO 80122 (US) LORANG, Michael, J. Englewood, CO 80122 (US) WOLD, Michael, O. Bozeman, MT 59715 (US) RAYFIELD, Jerry, W. Sylacauga, AL 35150 (US) (74) Representative: Williams, Trevor John  J.A. KEMP & CO. 14 South Square Gray's Inn London WC1R 5EU London WC1R 5EU (GB)