This work examined the feasibility of in-mine coal preparation. The work included a survey of previous investigations and a preliminary analyses of the economic and technical feasibility on a selection of representative sites and degrees of cleaning. The preliminary analysis determined that in-mine preparation systems can be applied using currently available technology. The most likely mines for application will have shaft or slope access and be deeper than 500 ft. The refuse disposal systems technically feasible are (1) pneumatic placement of coarse refuse in room-and-pillar panels or longwall faces, (2) mechanical placement of coarse and fine fractions in room-and-pillar panels, and (3) hydraulic placement of fine fractions in room-and-pillar panels. The economic feasibility is much more dependent on the refuse disposal system than on the preparation system. It is estimated that the capital cost of an in- mine preparation and disposal system would be $6.00 Per clean ton and the operating cost would be $1.24 Per clean ton for a 1-million- clean-ton-per-year mine.