MCL (Gravimelt) System Integration Project. Quarterly report, October--December 1988

The objective of this project is to construct and operate an integrated test circuit for the Molten-Caustic-Leaching (Gravimelt) process for desulfurization and demineralization of coal to prove process economics assumptions, deliver product coal and to test process conditions aimed at significantly lowering costs. The test circuit consists of six unit operations which together provide a continuous system for leaching coal and regenerating the reactant. These units are: (a) a kiln for reacting molten caustic with coal; (b) a seven stage water washing section for recovering caustic from the coal; (c) a three-stage acid washing section for removing the last traces of metals and alkali and providing an ultra pure coal product; (d) a water treatment section to provide either dischargeable or recyclable water; (e) a regeneration section to provide purified aqueous caustic; and (f) an evaporator section to provide molten-caustic for recycle to the kiln reactor. The integrated test circuit facility contains more than 160 pieces of equipment including filters, centrifuges, tanks, reactors, feeders and the kiln and rising film evaporator. It occupies 3700 square feet and is fitted with more than 6000 feet of piping, 425 valves, 80 instruments and controls as well as a control room with computer control and data acquisition and reduction system. The highlight of the quarter is completion of a week of around-the-clock shakedown of the integrated test circuit