PCT No. PCT/AU94/00301 Sec. 371 Date Mar. 6, 1996 Sec. 102(e) Date Mar. 6, 1996 PCT Filed Jun. 7, 1994 PCT Pub. No. WO94/28735 PCT Pub. Date Dec. 22, 1994A counter current extractor including an elongate housing with a screw conveyor therein and having a strainer at one end thereof to filter a liquid phase out of the counter current extractor, wherein the strainer is provided with a clearing member to prevent the strainer from remaining clogged with particulate material and wherein liquid being fed into the counter current extractor is spilled into the extractor so as to flow in a cascade over and through a solid phase in the extractor, the liquid being maintained at a desired level by a control member.