Dry Coal Preparation of Fine Particles by KAT Process

Abstract

In this study, effectiveness of KAT Process, dry coal preparation process developed by KIGAM (Korea Institute of Geoscience and Mineral Resources), was assessed for bituminous coal from MAK-Naryn Sukhait (NS) coal mine, Mongolia. 1-25 mm raw coal delivered from Mongolia was screened and classified with 1-5 mm, 5-10 mm, 10-20 mm, and over 20 mm particle size range. Separation tests were conducted for 1-5 mm and 5-10 mm size fractions using two types of pilot scale KAT Process units, suitable for each size range. Prepared test samples were concluded as well liberated samples having less than 3 % of weight material between specific gravity range of 1.6 to 2.0 g/cm³. Test results conducted under optimum conditions observed at previous investigations. Overall, the average ash rejection and combustible recovery for 1-5 mm fraction was 81% and 77% respectively and the feed ash content was decreased from 35% to 12% in product and the average product yield was 56.3%. The 5-10 mm size fraction average ash content was 48.4%. After the dry separation, about 41% of the feed was recovered as product with average 9.4% ash content. Ash rejection and combustible recovery was 91.7% and 76.8% respectively. Conducted tests showed that KAT process can effectively remove large amount of dense impurities from low grade coal thus producing an acceptable ash content clean coal product.