Thermal coal washing for slurry pipeline testing

Abstract

A 54 tonne raw coal sample composited from Judy Creek seams 3, 5 and 7 was submitted by Esso Mineral for use in pilot plant washing tests at Western Research Laboratory (WRL) and in slurry pipeline tests at Saskatchewan Research Council. The sample (54 tonnes) was not representative of the Judy Creek deposit. One-quarter of the sample was washed and the clean product along with raw coal samples shipped to Saskatchewan Research Council for slurry pipeline testing. Raw coal containing 18066 KS/Kg (33.2% ash-db) was crushed to minus 10mm and washed at cutpoints of 1.59 and 1.87. The clean products containing 23865 and 21911 KS/Kg (db) were obtained with thermal recoveries of 67.58 and 81.4% respectively. Crushing the coal to 10mm top-size improved the recoverability of coal at specific gravity cutpoints below 1.8. No significant size degradation was observed as a result of washing. The clean coal products from the two tests were blended giving a composite of 20.4% ash and shipped along with raw coal crushed to minus 10mm and coarse coal (minus 50.8mm) for slurry pipeline testing.