THIS PROGRAM WILL STUDY THE FEASIBILITY OF PREPARING LOW-ASH AND LOW-SULFUR MICRONIZED COAL BY USING A NOVEL MIXED-LIQUID ATTRITOR.

THIS PROGRAM WILL STUDY THE FEASIBILITY OF PREPARING LOW-ASH AND LOW-SULFUR MICRONIZED COAL BY USING A NOVEL MIXED-LIQUID ATTRITOR. MEASUREMENTS WILL BE MADE AT THE BENCH SCALE IN A BATCH-OPERATED ATTRITOR MODIFIED FOR THIS WORK. THE INNOVATIVE CONCEPT TO BE TESTED WILL INCLUDE: A MAJOR CHANGE IN ATTRITOR DESIGN, THE USE OF NOVEL MIXTURES OF CONVEYING LIQUIDS AS OPPOSED TO A SINGLE LIQUID NOW USED IN COMMERCIAL PRACTICE, AND THE USE OF NEW GRINDING MEDIA SPECIFIC TO PREPARATION OF ULTRA-CLEAN COAL. THE CONCEPT IS NOVEL BECAUSE SIZE REDUCTION AND FIRST-STAGE BENEFICIATION ARE CARRIED OUT IN THE SAME DEVICE. THIS CONCEPT WILL ENABLE MINERAL CONTAMINANTS TO BE LIBERATED FROM THE COAL AND REMOVED FROM THE GRINDING CHAMBER BEFORE THEY ARE OVERGROUND. THUS, EXPEDITIOUS SEPARATION OF THE LIBERATED MINERAL CONTAMINANTS BEFORE OVERGRINDING MINIMIZES THE GENERATION OF MINERAL SLIMES AND AIDS THIS AND SUBSEQUENT COA-CLEANING STAGES. FURTHER, THE CLEAN COAL SURFACES PREPARED IN THE NOVEL SIZE-REDUCTION OPERATION ARE PROTECTED FROM UNWANTED DEPOSITION OF MINERAL SLIMES BY THE USE OF THE NOVEL MIXTURE OF LIQUIDS. THIS IS EXPECTED TO FURTHER IMPROVE THE EFFICIENCY OF BENEFICIATION.