31
Colin J McKenny, Brian W Raymond: Coal flotation process. Fording Coal, Rodman & Rodman, August 22, 1995: US05443158 (28 worldwide citation)

A process for the flotation of particles of lignitic coal, subbituminous coal or oxidized bituminous coal contained within a slurry of coal and gangue, comprising the steps of dispersing a surfactant throughout the slurry, first conditioning the slurry such that the surfaces of the particles of coal ...


32
Hiroshi Kamada, Kazumoto Saito, Toshiaki Murata, Tadahisa Miwa, Masao Goto, Toshiro Fukuda, Hitoshi Taguchi: Coal treatment for ash removal and agglomeration. Sanyo Chemical, The Coal Mining Research Centre, Oblon Fisher Spivak McClelland & Maier, May 25, 1982: US04331447 (28 worldwide citation)

Coal particles can be agglomerated with simultaneous ash removal therefrom by adding an oil fraction to an aqueous slurry of coal particles which contains a surfactant and optionally an inorganic electrolyte.


33
Charles W Pruitt: Method of operation of nonrecovery coke oven battery. Sun Coal Company, Kerkam Stowell Kondracki & Clarke, June 7, 1994: US05318671 (27 worldwide citation)

A method of controlling operation of a nonrecovery coke oven battery including a plurality of elongated coke ovens constructed in side-by-side relation with each oven having a separate system of sole flues beneath each end connected to the crown of the oven by measuring the temperature in the oven a ...


34
Flame spraying refractory material. Coal, June 18, 1980: GB2035524-A (27 worldwide citation)

A method and apparatus for flame spraying refractory material to repair cavities 19 in refractory walls. The method comprises supplying to a lance a mixture of one or more finely divided refractory oxides and one or more finely divided metal or metalloid elements which are easily oxidisable to refra ...


35
Florentinus Melis, Jan Verbergt, Willy Van Rooy: Lighter for stove, open hearth and similar. Coal O Matic PVBA, Wood Dalton Phillips Mason & Rowe, March 10, 1987: US04649260 (26 worldwide citation)

There is described a lighter for ovens, open hearths and similar, which comprises a holder the one end of which on the one hand is extended with a support from fire-proof non-conducting material wherein an incandescent resistor is supported, which resistor may be engaged directly with the solid fuel ...


36
Robin M Howie: Helmet. Coal, Stevens Davis Miller & Mosher, August 1, 1989: US04852562 (26 worldwide citation)

A powered respirator helmet comprises a shell, having a passage, between a filter medium, and a fan, mounted in the front peaked part of the helmet shell. An air intake permits air to be drawn by the fan through the filter medium, through the passage and to be exhausted by the fan into the space bet ...


37
Gregory R Cooper, Robert J Pragnell: Method of forming a waterproof roof. Coal, Stevens Davis Miller & Mosher, June 2, 1987: US04670071 (26 worldwide citation)

A roofing method comprises applying to a roof deck a self-adhesive sheet comprising an adhesive and waterproofing layer of bituminous compound so that the sheet adheres to the deck over an area of 10-50% of the total sheet area and water vapor passing through the deck may escape laterally; rendering ...


38
Terence Geoffrey Martin: Hydrogenation of coal. Coal, Stevens Davis Miller & Mosher, July 19, 1977: US04036731 (25 worldwide citation)

The present invention relates to a process for the hydrogenative extraction of coal which comprises extracting finely divided coal at an elevated temperature between 340.degree. and 480.degree. C. with a gaseous solvent and a hydrogen donor, which solvent at the extraction temperature is above its c ...


39
Martin David James Reginald, Davis Quintin Visser: Radio frequency communication systems. Coal, Wray James C, October 28, 1975: US3916311 (25 worldwide citation)

A radio communication system suitable for use in tunnels and mines uses a leaky radiating transmission line connected between a transmitter and a receiver to transmit radio frequency signals to a local receiver. Unidirectional repeaters are located in the transmission line and a return path is provi ...


40
David J R Martin: Vehicle location system. Coal, James C Wray, December 16, 1986: US04630057 (25 worldwide citation)

A leaky-feeder or other form of guided radiocommunication system serving a linear route or track is equipped at intervals with static marker devices which successively modify a radio signal passing those points between a fixed base station and a personal or mobile station travelling the route. By re ...