HIGH-FREQUENCY HEATING OF GROUND COAL.

An experiment was run in Japan during which lump coal was placed in steel rotary drum, containing iron blocks. On the outside an induction circuit was installed and on the inside four longitudinal fins were placed. A high frequency current was supplied to the induction circuit that was used to subject the drum to induction heating. As a result of heating, cracks form in the coal which facilitate grinding. The researchers reached the conclusion that the use of induction heating during grinding of lump coal is promising.