ESTIMATION OF GRINDABILITY FROM SINK-FLOAT TEST DATA FOR 2 DIFFERENT COALS

An investigation conducted with a coking and non-coking coal, shows th at grindability of the coals is determined by the grindabilities of it s constituent specific gravity fractions and the weight percentage dis tribution of these same fractions. Though the grindability of the cons tituent specific gravity fractions of both the coals varies in a syste matic manner, certain differences, however, can be observed in the var iation pattern between the two coals. It is easier to grind the heavie st fraction of the coking coal than some of its neighbouring heavy fra ctions. The observed variation indicates the possibility of accurate e stimation of the grindability of both the coals studied from routine s ink-float data on the basis of the empirical relationship between cumu lative mean specific gravity and HGI of cumulative floats at successiv e specific gravities. (C) 1998 Elsevier Science B.V.