(19)

(11)

EP 0 480 921 A1

(12)

(43) Date of publication: 22.04.1992 Bulletin 1992/17 (21) Application number: 89904741.0 (22) Date of filing: 07.04.1989

(51) International Patent Classification (IPC):  B01D 17/ 02( . ) B04C 5/ 081( . ) B04C 3/ 06( . ) B04C 5/ 30( . ) (86) International application number: PCT/AU1989/000151 (87) International publication number: WO 1989/009653 (19.10.1989 Gazette 1989/25)

(84) Designated Contracting States: BE DE FR GB IT NL SE (30) Priority: 08.04.1988 AU 19880007635 14.10.1988 AU 19880000943 (71) Applicant: CONOCO SPECIALTY PRODUCTS INC. Houston, TX 77252 (US)	(72) Inventor: CARROLL, Noel Sassafras, VIC 3787 (AU) (74) Representative: Geering, Keith Edwin, et al  REDDIE & GROSE 16 Theobalds Road London WC1X 8PL London WC1X 8PL (GB)