Recovery of Fine Coal Grains from Post-Mining Wastes with Use of Autogenous Suspending Bed Technology

In addition to rock waste post-mining waste dump sites also contain coal grains justifying treating the dump sites as secondary mineral deposits. The article presents the results of laboratory tests aimed at determining the possibility of using suspending bed technology to separate a combustible substance from post-mining waste of a 4-0 mm grain size. The test results showed the possibility of obtaining good quality coal concentrates from coal waste of a grain size of 4-1 mm. The need for desludging and densifying the feed for the classifier with an autogenic suspending bed in the case of coal waste beneficiation in a wide 4-0 mm grain size justifies the use of a two-chamber device or two separate classifiers for narrower grain size classes. Concepts of systems for the recovery of fine coal grains providing the use of the classifier with autogenous suspending bed for the density distribution of feeds with high ash content are presented. The concepts were developed for beneficiation of the material in a 4-0 mm grain class.