OPTIMUM AIR-SPARGED HYDROCYCLONE FLOTATION FOR FINE COAL CLEANING WITH A PRESSURE SENSING CONTROL STRATEGY

RECENT TESTING OF AIR-SPARGED HYDROCYCLONE (ASH) FLOTATION TECHNOLOGY FOR FINE COAL CLEANING AT THE EPRI/CODC TEST FACILITY HAS SHOWN THAT THE ASH SYSTEM HAS GREAT POTENTIAL FOR UTILIZATION IN THE COAL INDUSTRY. HOWEVER, EFFECTIVE UTILIZATION OF THIS TECHNOLOGY RELIES ON OPTIMUM CONTROL ANDCONTINUAL ADJUSTMENT OF MANIPULATED VARIABLES WITH RESPECT TO FLOTATION PERFORMANCE SINCE THE RETENTION TIME OF COAL/WATER SLURRY IN THE ASH UNIT IS LESS THAN ONE SECOND. FLUCTUATION OF OTHER OPERATING VARIABLES IN PLANT OPERATION AND THE CURRENT INABILITY TO RAPIDLY DETERMINE CHANGES IN FLOTATION PERFORMANCE IN REAL TIME HAVE LIMITED THE USE OF THE ASH TECHNOLOGY IN COAL PREPARATION PLANTS. PRELIMINARY STUDY INDICATES THAT A CORRELATION BETWEEN PRESSURE MEASUREMENTS, OPERATING VARIABLES, AND FLOTATION PERFORMANCE CAN BE ESTABLISHED AND SUCH A CORRELATION MODEL CAN BE USED AS A BASIS TO CONTROL FLOTATION PERFORMANCE. SINCE THESE PRESSURE MEASUREMENTS CAN BE DETERMINED IN REAL TIME DURING ASH FLOTATION, AUTOMATIC CONTROL AND OPTIMUM ADJUSTMENT OF THESE MANIPULATED VARIABLES CAN BE ACCOMPLISHED. IN THIS REGARD INITIAL STUDY OF THE PROPOSED CONTROL STRATEGY IN PHASE I SBIR PROGRAM IS WARRANTED.