DEVELOPMENT AND TESTING OF A VERTICAL CENTRIFUGE SEPARATOR FOR DENSITY-BASED FINE COAL SEPARATIONS

IN RECENT YEARS, A NUMBER OF ADVANCED PHYSICAL COAL CLEANING PROCESSES DESIGNED TO GENERATE EXTREMELY LOW ASH AND PYRITIC SULFUR CONTENT PRODUCTS HAVE BEEN INVESTIGATED. ALL THESE PROCESSES INCORPORATE FINE TO EXTREMELY FINE GRINDING OF THE COAL TO LIBERATE MINERAL PARTICLES, PARTICULARLY PYRITE, FROM THE COAL'S MATRIX PRIOR TO SEPARATION. ONE OF THE PROCESSES, THE HEAVY-LIQUID-CYCLONING TECHNOLOGY, PROVED VERY EFFICIENT AT PYRITIC SULFUR AND ASH REMOVAL (80% - 95%) DURING PRELIMINARY DEMONSTRATION SCALE TESTING. HOWEVER, A NUMBER OF TECHNICAL SHORTCOMINGS NEED TO BE OVERCOME THROUGH FUTURERESEARCH BEFORE THE TECHNOLOGY IS READY FOR COMMERCIALIZATION. THIS PROPOSED RESEARCH PROJECT WILL INVESTIGATE THE FEASIBILITY OF SUBSTITUTING A NOVEL CENTRIFUGE SEPARATOR, DESIGNED BY PTI AND DOE STAFF, FOR HYDROCYCLONES IN THE HEAVY-LIQUID CLEANING PROCESS. THE CENTRIFUGE IS DESIGNED TO OVERCOME CERTAIN LIMITATIONS OF CYCLONE CLEANING, NAMELY THE INABILITY TO EFFICIENTLY CLEAN THE EXTREMELY FINE SIZES (-325M) OR OPERATE IN HIGHLY VISCOUS LIQUID MEDIAS. THE PROTOTYPE CENTRIFUGE SEPARATOR WILL BE EVALUATED BASED ON SIDE-BY-SIDE COMPARATIVE TESTING WITH CONVENTIONAL CYCLONES USING VARIOUS COAL FEEDS AND HEAVY-LIQUID MEDIAS.