Electrophoretic mobility measurements of coal and pyrite particles in distilled water revealed a difference between the migration speeds of the two materials toward the anode in a DC electric field. This information led to the development of a laboratory electrophoresis column for separating fine pyrite from coal by utilizing the electrokinetic and the specific gravity differences between coal and pyrite. The study demonstrated on a laboratory scale that pyrite and other impurities can be separated from fine coal by electrophoresis using a stage separation technique. In a cost analysis, electrical power for electrophoresis was extrapolated to about $1 per ton of clean coal product. However, the cost figure derived is not representative of conditions prevalent in commercial coal cleaning operations. True conditions would reflect costs many times as great. Several scale-up techniques were considered, but their feasibility became academic in view of the physical and economic problems associated with electrophoretic separation of pyrite from coal. Nevertheless, the electrophoresis column may have some application as a laboratory device. Work upon which this report is based was funded by the office of air programs of the Environmental Protection Agency.