Size separation inefficiency in the fine particle size range of 150 mum and finer has been a perennial problem in coal preparation plants. A close examination of many plant data indicate that both quantity and quality of the clean coal product from the fine circuit of a plant may be significantly increased by improving the efficiency obtained for the size separations at 150- and 45-mum particle size. Thus, this investigation has concentrated in optimizing the fine size separation performance of a newly developed screening technology, known as the Pansep Screen. Statistically designed factorial experiments have been conducted to obtain the optimum size separation performance from the Pansep screen at d(50c) sizes of 150 and 45 mum. The results of this study indicate that near-perfect size separation efficiency of nearly 98% is achievable from the Pansep screen in comparison to below 60% obtained from the classification technologies conventionally used in the preparation plants. High oversize product throughput capacity of 7 and 5 tph/m(2) were achieved for efficient 150- and 45-mum size separations, respectively. (C) 2003 Elsevier Science B.V. All rights reserved.