In the art world, it is fostered by an incessant rain of numbers in the media whenever an art star comes to its attention. Graffiti Artists Turn on Banksy: The Rise of Art Hate Anthony Haden-Guest August 6, 2014
For the music genre, see Sludge metal. Sludge. Sludge is a semi-solid slurry and can be produced as sewage sludge from wastewater treatment processes or as a settled suspension obtained from conventional drinking water treatment and numerous other industrial processes.
Coal slurry. Coal slurry is a mixture of solids (mined coal) and liquids (usually water) produced by a coal preparation plant. As a slurry, coal is separated from non-combustable components (ash) and can be fractionated by particle size as well.