Response of mineral separator for fine coal beneficiation

Abstract

Indian coking coal washeries employ coarse and medium coal gravity concentration techniques for processing of 80-90% of coal and balance being processed by f lotation mainly. In case of fine coal also new develop¬ments are oriented towards the use of gravity concentration systems. Washability of coal is an important criteria to evaluate the performance of the separating systems. Washability studies consumes expensive reagents like bromoform, carbon tetra-chloride, benzene, acetone etc. Washability of fine coal is still more complicated due to reagent retention, use of heavy liquid centrifuge etc. An attempt has been made to use Mozley Mineral Separator to produce an ash-yield relationship using a coal sample of 36% ash. The results have been compared and analysed against the washability data to find out efficacy of the Mineral Separator. Tabling and flotation studies were also carried out on the same sample. The study reveals that while there is a deviation at low ash level, Mineral Separator can produce an ash-yield relationship nearly similar to washability data at higher ash level. While sink float provides an ideal separation the mineral separator provides data obtainable in separating system. Studies on tabling and flotation with the sample also indicate that the ash yield relationship is quite close to that of mineral separator.