Blackwater is a form of pollution produced in coal preparation.[1][2] In its purification, coal is crushed in a coal preparation plant and then separated and transported as a coal slurry, From the slurry, incombustible materials are removed and the coal can be sized. After the recovery of the coal particles from this slurry, the remaining water is black, contains very fine particles of coal. This blackwater cannot be processed in a water treatment plant.[3][why?]
^Fitz Patrick, J. A.; Vallario, R. W. (1981). "Modelling and Control of Blackwater Treatment in Coal Preparation". Separation Science and Technology. 16 (10): 1633–1666. doi:10.1080/01496398108058319.
^Rey, P. A.; Hogg, R.; Aplan, F. F. (1983-04-29). "Control of blackwater in coal preparation plant recycle and discharge. Open file report Oct 79 – Sep 82 (final)". Pennsylvania State Univ. OSTI5842936.
^Shiao-Hung Chiang and James T. Cobb "Coal Conversion Processes, Cleaning and Desulfurization" in Kirk-othmer Encyclopedia of Chemical Technology Wiley-VCH, 2000. doi:10.1002/0471238961.0312050103080901.a01