Process for heat treatment of coal
AssigneeMitsubishi Jukogyo Kabushiki Kaisha
InventorsYoshifumi Ito, Yoshihiko Nishimoto, Kiyomichi Taoda, Fumiaki Sato, Takashi Ueda, Seibi Uehara
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Abstract
In a process for heat treatment, highly hygroscopic coal, with a low carbon content and large equilibrium moisture, is rapidly heated with hot gas at a rate of temperature rise of at least 100.degree. C./min up to a final heating temperature in the range of 300.degree.-500.degree. C., and is then rapidly cooled at a rate of temperature drop of at least 50.degree. C./min to 250.degree. C. or below. As the hot gas, an inert gas whose oxygen concentration is not higher than 4% by volume is employed. The hot gas is either caused to contain not less than 20% by volume of steam or composed solely of the steam.
Claims5
A process for the heat treatment of highly hygroscopic coal having a low carbon content and high equilibrium moisture to produce a less hygroscopic coal which comprises rapidly heating the coal with hot gas at a rate of temperature rise of at least 100.degree. C./min up to a final heating temperature in the range of 300.degree.-500.degree. C., and then rapidly cooling the same at a rate of temperature drop of at least 50.degree. /min to not higher than 250.degree. C., said hot gas comprising an inert gas with an oxygen concentration of not more than 4% by volume.
Dependencies are inferred from the claim text.