Generation of fines by crushing the raw coal to different sizes and effects of lab flotation tests on its results using these coal fines

Abstract

The beneficiation of coal needs reduction in size for processing and to produce cleans of desired quality for its proper utilization. The crushing size depends on the consumer’s requirement and hence the coals may be crushed to different sizes for further processing. The crushing of coal generates fines (–0.5 mm) and its quality, quantity and particle size distribution vary depending on the top size of crushing. Forth flotation is the established process for the upgradation of coal fines. The flotation circuits have been incorporated in most of the coking coal washeries in India. Keeping in view of the above fact lab tests were designed to upgrade the fines generated by crushing the coal at 3 (three) top sizes i.e. 75, 20, and 10 mm. Coal fines from the above-noted crushing were analysed in terms of size distribution and floatability by carrying out froth flotation tests. It was observed from the test results that a yield of 62% at 12.7% ash level may be achieved with the normal dosage of collector and frother when the raw coal was crushed to 10 mm.