Abstract: A process for automating fine coal cleaning including monitoring the operation of a flotation cell for separating coal from ash impurities by automatically detecting the coal content of the tailings from the cell and controlling the supply of additives to the cell to optimize slurry coal recovery and automatically monitoring the fluid level of the coal slurry in a dewatering filter tub to control the supply of additives to the filter tub and functioning of a dewatering filter.

Abstract: Pyrite is removed from coal by crushing, air classification and organic heavy medium separation. A superior method is taught wherein only a fraction of the total coal treated need be treated with organic media separation.

Abstract: Subterranean coal seams are treated with ammonia to enhance methane removal and improve the mineability of coal. Residual ammonia remaining from the coal treatment is removed by contacting the coal seam with nitrifying bacteria after ammonia treatment and before mining is carried out.

Abstract: A low pressure, low temperature, hydrometallurgical process for the recovery of metal values from chalcopyrite and other metals and other metal sulfides. The process provides for all sulfur recovery as sulfuric acid and is nonpolluting, uses no neutralizing agents, and produces no waste products.

Abstract: Sulfur monochloride is reacted with an ore containing iron, sulfur and a metal which forms a water soluble ammine complex or an ammonium-containing double salt, to yield metal chlorides and sulfur. The metal sought is solubilized with an aqueous solution containing ammonium ions to produce an aqueous solution of metal ammine complex or double salt and thereby separate such complex or salt from the iron and sulfur. The solution containing the sought metal values can then be subjected to electrowinning to recover the metal, or the metal can be precipitated as the metal oxide by the addition of sodium hydroxide. Sulfur and chlorine are recovered during the process and used to regenerate sulfur monochloride.

Abstract: Certain mineral values are recovered from source material such as ore, scrap metal, and mixtures in the presence of another metal thereof by aqueous ammonia leaching solution, and the mineral values are precipitated by ammonia from said solution as a complex, and the mineral values are recovered from said complex.

Abstract: The present invention relates to an improved method of transporting a sulfur-hydrocarbon slurry in a pipeline with a minimum of sulfur precipitation and adherence to the internal parts of the pipeline system. The improvement comprises maintaining the flow rate of the slurry to at least about the value given by the equationflow rate (feet per second) = 0.16 [.DELTA.T(.degree.F)-5]when the flow rate is below 8.0 feet per second, to thereby prevent the plating of sulfur on the walls of the pipeline by the precipitation of the dissolved sulfur in the sulfur-hydrocarbon slurry.