To evaluate the comprehensive exploitation and utilization values of coal resources in Baise basin of Guangxi, the Paleogene coal of Linchang coal mine were sampled and studied. The enrichment characteristics, occurre...To evaluate the comprehensive exploitation and utilization values of coal resources in Baise basin of Guangxi, the Paleogene coal of Linchang coal mine were sampled and studied. The enrichment characteristics, occurrence modes, and geochemical origin of valuable trace elements in coal were studied by using X-ray diffraction (XRD), scanning electron microscope-energy dispersive X-ray spectrometer (SEM-EDS), polarizing microscope, X-ray fluorescence spectrometry (XRF), inductively coupled plasma mass spectrometry (ICP-MS) and atomic fluorescence spectrometry (AFS). The results reveal that Linchang coal is ultra-low calorific value lignite with high ash, medium sulfur, medium-high moisture and medium volatilization. The minerals are mainly composed of illite, kaolinite, quartz, pyrite, siderite, bassanite, anhydrite and magnesium-containing calcite. Compared with average values for world low-rank coals, the contents of valuable trace elements in Linchang coal are higher on the whole, which is characterized by the high enrichment o<span>f U, the enrichment of elements Li, V and Ag, and the slight enrichment of</span> elements Be, Ga and Se. Lithium, V, Ga and Ag mainly occur in clay minerals including illite and kaolinite, and part of V is related to organic matter. Th<span>e carriers of Be in coal are clay minerals and organic matter. Selenium is </span>mainly combined with organic matter and a small amount exists in pyrite. Uranium is primarily organically bound in coal. The enrichment of valuable trace elements in Linchang coal is influenced by the sedimentary source, coal<span>-forming environment, underground circulating water and geological structure. The sedimentary environment of the coal seam is an acid-reduced terrestrial peat swamp, and the source is Triassic sedimentary rocks weathered f</span>rom feldspathic volcanic rocks around Baise basin.展开更多
Lead is a potentially harmful element that has caused serious environmental pollution during its mining and use along with serious human health problems.This study assessed lead in Chinese coals based on published lit...Lead is a potentially harmful element that has caused serious environmental pollution during its mining and use along with serious human health problems.This study assessed lead in Chinese coals based on published literature,with a particular focus on data reported since 2004.The analysis included 9447 individual samples from 103 coalfields or mines in 28 provinces in China.The arithmetic mean content of lead in the studied coals was 15.0μg/g.Considering the coal reserves,the weighted-average lead concentration in Chinese coals was calculated to be 19.6μg/g.Lead was significantly enriched in the coals from Henan Province and enriched in the coals from the Tibet Autonomous Region.The coals from Tibet–Western Yunnan and the southern areas of China had elevated lead concentrations.Sulfides are the primary hosts of lead in Chinese coals,although other hosts include silicates,organic matter,carbonates,and other minerals.Source rocks in the sediment-source region and marine environments may be the most significant factors contributing to lead enrichment in Chinese coals.Hydrothermal fluids and peat-forming plants also contribute to lead enrichment in some Chinese coals.展开更多
文摘To evaluate the comprehensive exploitation and utilization values of coal resources in Baise basin of Guangxi, the Paleogene coal of Linchang coal mine were sampled and studied. The enrichment characteristics, occurrence modes, and geochemical origin of valuable trace elements in coal were studied by using X-ray diffraction (XRD), scanning electron microscope-energy dispersive X-ray spectrometer (SEM-EDS), polarizing microscope, X-ray fluorescence spectrometry (XRF), inductively coupled plasma mass spectrometry (ICP-MS) and atomic fluorescence spectrometry (AFS). The results reveal that Linchang coal is ultra-low calorific value lignite with high ash, medium sulfur, medium-high moisture and medium volatilization. The minerals are mainly composed of illite, kaolinite, quartz, pyrite, siderite, bassanite, anhydrite and magnesium-containing calcite. Compared with average values for world low-rank coals, the contents of valuable trace elements in Linchang coal are higher on the whole, which is characterized by the high enrichment o<span>f U, the enrichment of elements Li, V and Ag, and the slight enrichment of</span> elements Be, Ga and Se. Lithium, V, Ga and Ag mainly occur in clay minerals including illite and kaolinite, and part of V is related to organic matter. Th<span>e carriers of Be in coal are clay minerals and organic matter. Selenium is </span>mainly combined with organic matter and a small amount exists in pyrite. Uranium is primarily organically bound in coal. The enrichment of valuable trace elements in Linchang coal is influenced by the sedimentary source, coal<span>-forming environment, underground circulating water and geological structure. The sedimentary environment of the coal seam is an acid-reduced terrestrial peat swamp, and the source is Triassic sedimentary rocks weathered f</span>rom feldspathic volcanic rocks around Baise basin.
基金This research was supported by National Natural Science Foundation of China(Grant No.4197217,41472136)Special thanks are given to Shifeng Dai and two anonymous reviewers for their useful suggestions and comments.
文摘Lead is a potentially harmful element that has caused serious environmental pollution during its mining and use along with serious human health problems.This study assessed lead in Chinese coals based on published literature,with a particular focus on data reported since 2004.The analysis included 9447 individual samples from 103 coalfields or mines in 28 provinces in China.The arithmetic mean content of lead in the studied coals was 15.0μg/g.Considering the coal reserves,the weighted-average lead concentration in Chinese coals was calculated to be 19.6μg/g.Lead was significantly enriched in the coals from Henan Province and enriched in the coals from the Tibet Autonomous Region.The coals from Tibet–Western Yunnan and the southern areas of China had elevated lead concentrations.Sulfides are the primary hosts of lead in Chinese coals,although other hosts include silicates,organic matter,carbonates,and other minerals.Source rocks in the sediment-source region and marine environments may be the most significant factors contributing to lead enrichment in Chinese coals.Hydrothermal fluids and peat-forming plants also contribute to lead enrichment in some Chinese coals.
