The concentration, distribution, and occurrence of rare earth elements (REEs) in coals as well as stone coalsin different geological periods from Chongqing were studied. The results show that the REE content in coals ...The concentration, distribution, and occurrence of rare earth elements (REEs) in coals as well as stone coalsin different geological periods from Chongqing were studied. The results show that the REE content in coals fromChongqing is much higher than that of the ordinary Chinese coals, the Late Paleozoic coals from North China, UScoals, and the world coals. Although the concentration of light rare earth elements (LREE) is higher than that of heavyrare earth elements (HREE), the ratio of LREE to HREE is as low as 5.11. The REE content decreases with thecoal-formation periods from old to new. The REE content in the Sinian stone coal is the highest, but it is the lowest inEarly Jurassic coals. The similar REE contents in bituminous coals and anthracite show that the metamorphism has alittle influence on REE content in coal. In addition, silicate association dominates the occurrence mode of REEs incoals from Chongqing.展开更多
The Permian coal in southwest China contains highest sulfur among the Chinese coal .Compositional variations of sumir in coal are mainly controlled by palaogeographital environmentsduring peat accumulation. High organ...The Permian coal in southwest China contains highest sulfur among the Chinese coal .Compositional variations of sumir in coal are mainly controlled by palaogeographital environmentsduring peat accumulation. High organic sulfur coal is formed in peat swamp developing in tidal flat of limited carbonate platform, and it is provided with especial petrologital and geochemical characteristics, and its organoschr-containing compounds are mainly thiophene series. The macroscopitaland microscopical shapes or types of pyrites in Late Permisn coal are diversined. Bituminous coal and anthracite are diamagnetic, but the pyrites are paramagnetic. The magnetic susceptibility oftbe pyrites is depended on the content of paramagnatic elements associnted with pyrites.展开更多
文摘The concentration, distribution, and occurrence of rare earth elements (REEs) in coals as well as stone coalsin different geological periods from Chongqing were studied. The results show that the REE content in coals fromChongqing is much higher than that of the ordinary Chinese coals, the Late Paleozoic coals from North China, UScoals, and the world coals. Although the concentration of light rare earth elements (LREE) is higher than that of heavyrare earth elements (HREE), the ratio of LREE to HREE is as low as 5.11. The REE content decreases with thecoal-formation periods from old to new. The REE content in the Sinian stone coal is the highest, but it is the lowest inEarly Jurassic coals. The similar REE contents in bituminous coals and anthracite show that the metamorphism has alittle influence on REE content in coal. In addition, silicate association dominates the occurrence mode of REEs incoals from Chongqing.
文摘The Permian coal in southwest China contains highest sulfur among the Chinese coal .Compositional variations of sumir in coal are mainly controlled by palaogeographital environmentsduring peat accumulation. High organic sulfur coal is formed in peat swamp developing in tidal flat of limited carbonate platform, and it is provided with especial petrologital and geochemical characteristics, and its organoschr-containing compounds are mainly thiophene series. The macroscopitaland microscopical shapes or types of pyrites in Late Permisn coal are diversined. Bituminous coal and anthracite are diamagnetic, but the pyrites are paramagnetic. The magnetic susceptibility oftbe pyrites is depended on the content of paramagnatic elements associnted with pyrites.
