Medium good
As a medium material is referred to coal , at a larger portion of waste rock adheres. A part of the central material can with the aid of the method of the coal washing is prepared which does not aufbereitbare part ( low-grade coal ) is used as fuel in coal-fired power plant .
literature
- Walter Bischoff , Heinz Bramann, Westfälische Berggewerkschaftskasse Bochum: The small mining dictionary. 7th edition, Verlag Glückauf GmbH, Essen, 1988, ISBN 3-7739-0501-7