This report describes the results of process and cost refinement studies for the manufacture of ultra-clean coal-slurry fuel for direct-fired gas turbines. The work was performed as an extension to an earlier contract in which AMAX R and D supplied METC with two lots of highly beneficiated coal slurry fuel for use in the Heat Engines program. A conceptual design study and cost estimate supplied to METC at that time indicated that a combined physical and chemical cleaning process could produce ultra-clean fuel at a competitive price. Laboratory and pilot plant studies performed for the contract extension further defined the process conditions and operating and capital costs to prepare coals containing from 0.2 to 1.0% ash as slurry fuels. A base-case fuel containing coal cleaned to 0.5% ash in a 1000 cp slurry containing 55% coal was $4.16 per million Btu when produced in quantities required to fuel a 500 MW gas-turbine generating station. Coal slurry fuel production costs as low as $3.66 per million Btu were projected for coals cleaned to 1.0% ash. 12 refs., 23 figs., 63 tabs.