Methods of increasing the calorific value of fine coal waste

Abstract

The most frequent solution of water-slime industry in mines and companies working on coal output enrichment is linking watercourses from individual technological nodes into one stream of water-slime slurry. The outcome of such solutions is water-slime mixture of averaged composition and physicochemical properties. Depending on the applied slurry dewatering methods, we obtain cakes of slime coal mixtures or/and, in the case of gravitational dewatering of slurry in settlings, slimes diversed in composition in relation to the place of sedimentation. Among all studied various methods of coal concentrates extraction from slime - water slurries, the most interesting results are these of industrial significance obtained on mesh sieves. The new production of arched and centrifugal sieves (the so-called OSO), with minimum mesh size, enables selective coal concentrates extractions from coal slimes. The recovery of coal concentrates from flotation wastes is more difficult and most often the best results are ensured through application of flotation processes. The conducted research of fine-grained coal wastes and side products of coal combustion lay a fundament to elaboration of new technology, pilot installations and incorporation completion.