Abstract: A circular solvent extractor useful in a commercial process for the removal of bitumen from tar or oil sands or other solvent extraction processes requiring high tonnage throughput. The extractor comprises two major segments that are stationary, namely, a ring-shaped roof member and a ring-shaped drain trough means positioned therebeneath, and one segment that is movable which comprises a pair of continuous, spaced-apart sidewalls having a plurality of spaced-apart, liquid permeable, process cells rotatably attached to the sidewalls. The sidewalls and their attached process cells are movable about a circular trackway for travel between the fixed hood and drain trough means, forming an annular process chamber therearound. The annular chamber is sealed by upper and lower, circumferential liquid seals coacting between the moving sidewalls and the stationary hood and drain trough means to prevent the leakage of solvent vapors therefrom.