Abstract: An apparatus for the countercurrent extraction of liquids, forming a portion of solids, from such solids includes a rotary drum having an axis which is substantially horizontal. An inner partition is positioned within the drum and is substantially in the shape of a spiral formed by spiral turns having spaces therebetween. Each space has a raising element which lifts the solids from the liquid and a barrier over which the solids drop from the raising element and which stops the liquid and forces it back into an adjacent space during rotation of the drum. The raising element has a curvature such that the solids are lifted from the liquid and gradually drop in successive fractions over the barrier without sliding on the raising element.