Composition and mode of occurrence of minerals in Late Permian coals from Zhenxiong County,northeastern Yunnan,China

Minerals in the Late Permian coals from the Niuchang-Yigu mining area,Zhenxiong County,northeastern Yunnan,China,were investigated using optical microscopy and low temperature ashing plus X-ray diffraction(LTA?XRD).The results showed that minerals in the coal LTAs are mainly quartz,kaolinite,chamosite,mixed-layer illite/smectite(I/S),pyrite,and calcite,with trace amounts of marcasite,dolomite,and bassanite.The authigenic quartz generally occurs in collodetrinite or as a filling in cleats or cell cavities.This silica was mainly derived from aqueous solutions produced by the weathering of basaltic rocks in the Kangdian Upland and from hydrothermal fluids.The presence of b-quartz paramorph grains in collodetrinite probably indicates that these grains were detrital and came from a volcanic ash.Clay minerals are generally embedded in collodetrinite and occur as cell-fillings.Pyrite occurs as framboidal,anhedral,and euhedral grains and a cell-filling.The coals are high in pyrite and the high pyrite content probably results from seawater invading during the stage of peat accumulation.Calcite generally occurs as vein-fillings,indicating an epigenetic origin.

Trace elements of Carboniferous–Permian coal from the Adaohai Mine, Daqingshan Coalfield, Inner Mongolia, China

A total of 48 samples of Carboniferous–Permian coal was taken from the Adaohai Mine, Daqingshan Coalfield, Inner Mongolia, China. Cu2 coal is the major coalseam of the Daqingshan Coalfield. The samples were analyzed by the ?nductively coupled plasma–mass spectrometer method.The results indicate the content of V, Cr, Cu, Zn, Ga, Se, Ag,Cd, In, Ba, Pb and U of the Cu2 coals from Adaohai Mine is higher than that of the common Chinese coals. Compared to the world hard coals, the content of V, Cu, Zn, Ga, Se, Sr, Ag,Cd, In, Ba and U is relatively high. Compared to the clark values of the crust, only elements Se, Ag, Pb and Bi are enriched in the coal. Most of the elements in coal benches are lower than in those in roofs and partings. The statistical analysis and clustering analysis showed that the modes of trace elements occurrence for the Cu2 coal correlated positively with the minerals. The values of Sr/Ba show that the coal forming environment was influenced both by sea water and fresh water.

Geochemical anomaly and the causes of transition metal accumulations in late Permian coal from the eastern Yunnan-western Guizhou region

The concentration of 39 trace elements in coal from the late Permian taken from the eastern Yunnan-western Guizhou region was determined using inductively coupled plasma mass spectrometry. It was found that the mean content of Ti, V, Cr, Mo, Co, Ni, Y, and Zr is higher than the national average. The occurrence of Mn, Ni, and Co in the different coalfields is distinctly different. Most of the enriched transition metal elements exist mainly as inorganic minerals. In the Zhina coalfield, Co, Ni, and Nb are primarily associated with sulfur. Mn, Cs, and Mo are mostly sulfides. Almost all Co was organic and a significant part of the Ni is also organic in the Liupanshui coalfield. Cs, Co, and Ni are related to sulfur in the coal taken from eastern Yunnan. Carbonate is the main form of Mn in the coal from eastern Yunnan and the Liupanshui coalfield. Ti is the oxide in the coal samples where Ti is enriched. Zr is in the form of zircon in the samples where Zr is enriched. The situation for most of the transition metal elements is consistent with terrestrial genesis. Coal seams are universally influenced by the sea. The strongly seawater effected peat bog with a reductive and alkaline environment favors the relative enrichment of Mn. A reducing environment is conducive to transition metal element enrichment.

The Formation Models of Sulfur in the Late Permian Coal of Sichuan

On the basis of the study on the occurrence and distribution of sulfur in the Late Permiau high-sulrur coals of Sichuan .Southwest China,the paper discusses the geological ractors influencing sulfur occurrence in coals, and suggests two evolutionary motlels, i. e. a directly depositional pyrite series(euhedral crystal→aggregate→glomerocryst ) and complex genetic series (mini→granular, framboid→spherical→nodular,lumpy pyrite). They are of theoretically and actually important significance not only in the explanation to the difference in composition of varioas types of coal pyrites,but also in the understanding of the mechanism of physical properties (magnetic,surface property) of pyrites. By a comprehansive analysis,a genetic model of sulfur in the Late Permian coal of Sichuan has been established.

Research on the environmental trace elements in permian coals and their ashes from Huainan coalmine area,China

The contents of environmental trace elements in permian coal from Huainancoalmine area and their combustion products were tested by ICP-MS.Analysis and comparativeresearches on the contents of eighteen environmental trace elements in coal andits combustion product suggest that Se and Cd have a high level of distribution in coals;As, Se, Cd, Sb and As, Se, Cd, Mo, Be, Sb also have a high level of distribution in 815 ℃and 1 100 ℃ coal ashes, respectively.Combustion temperature, thermodynamics featuresof trace elements and ash content in coal are the main factors that influence theabundance of trace elements in coal and ash.

Geochemical characteristics of Lower Permian coal-measure source rocks in Northeast Ordos Basin

General characteristics and biomarker distributions of Lower Permian coal-measure source rocks in northeastern Ordos Bsain have been analyzed in this paper. The results show that the source rocks are type Ⅲ kerogen, thermally mature, with high content of total organic carbon. The extracts of the source rock samples with different lithologies from Well Su 27 feature high Pr/Ph ratios, high C19 TT and C24 Te, high rearranged hopanes, a predominance of C29 sterane in regular steranes, and the absence of C30 4-methylsteranes. These data suggest that the source rocks were deposited in suboxic to oxic conditions with dominantly terrigenous higher plant input. In contrast, the source rocks from wells Shuang 1 and Yu 20, are characterized by low Pr/Ph ratios, low C19 TT and C24 Te, high C23 TT, similar content of C27 sterane and C29 sterane, and the presence of C30 4-methylsteranes, showing that the source rocks were deposited in reducing environment with algae and/or microorganisms and terrigenous higher plant input.

Study on REEs as tracers for late permian coal measures in Bijie City,Guizhou Province,China

Analyses of Rare Earth Elements (REEs) in 13 coal samples collected from Late Permian coal measures of Bijie City in western Guizhou Province were conducted using Inductively Coupled Plasma-Mass-Spectrometry (ICP-MS). The results indicated that REEs pat- terns were not controlled by materials from the sea, whereas the contribution of land plants was about 1%. The major sources of REEs were from terrigenous material as indicated by negative Eu anomaly. There were similar distribution curves of REEs between Bijie's coal and Emeishan basalt. M12 coal seam, which had the highest ∑REE, appeared near the boundary between Longtan Formation and Changxing Formation, which was closely correlated to the eruption of Emeishan basalt. The Emeishan basalt contributed to REEs enrichment of M12. So the sources of REEs were controlled by terrigenous material, and the Emeishan basalt was the predominant source of terrigenous material, which dominated the enrichment and pattern of REEs in Late Permian coal measure from Bijie.

Paleo-fires and Atmospheric Oxygen Levels in the Latest Permian:Evidence from Maceral Compositions of Coals in Eastern Yunnan,Southern China

从三节在的晚二叠的煤的 Inertinite maceral 作文陆上并且东方云南的 paralic 背景被分析以便揭示 paleo 火事件和大气的氧层次在最近二叠。尽管在学习的节的 macerals 被 vitrinite 通常统治， inertinite 组完成一个可观的比例。它的内容从开始向上增加对二叠三叠纪的边界附近的煤缝接晚二叠。基于显微镜的特征和 inertinite 大部分是 paleo 火的一个副产品的占优势的理论，我们建议向上增加 inertinite 丰富在的趋势最近二叠能暗示晚二叠的 peatland 受不了经常的野火。自从点火并且烧取决于足够的氧，基于模型的计算建议 O2 层次接近 Wuchiapingian/Changhsingian 边界，二叠三叠纪的边界分别地是 27% 和 28% 。这产量把支持加到在时间的海洋、陆上的沉积做的另外的发现，并且质问为二叠三叠纪的边界危机作为机制倡导组织缺氧的理论。

Geochemistry and mineralogy of the Late Permian coals from the Songzao Coalfield, Chongqing, southwestern China

Mineralogy and geochemistry of the four main workable coal seams (No.6, No.7, No.8, and No.11) of Late Permian age from the Songzao Coalfield, Chongqing, Southwest China, were examined using in- ductively coupled plasma-mass spectrometry (ICP-MS), X-ray fluorescence spectrometry (XRF), cold-vapor absorption spectrometry (CV-AAS), ion-selective electrode (ISE), scanning electron mi- croscopy equipped with an energy-dispersive X-ray spectrometer (SEM-EDX), and X-ray diffraction analysis (XRD). The results showed that the main workable No.8 Coal that accounts for about 60% of the total coal reserves in the Songzao Coalfield was not enriched in hazardous trace elements. The No.11 Coal has high concentrations of alkaline elements, Be (9.14 μg/g), Sc (12.9 μg/g), Ti (9508 μg/g), Mn (397 μg/g), Co (23.7 μg/g), Cu (108 μg/g), Zn (123 μg/g), Ga (32 μg/g), Zr (1304 μg/g), Nb (169 μg/g), Hf (32.7 μg/g), Ta (11.4 μg/g), W (24.8 μg/g), Hg (0.28 μg/g), Pb (28.1 μg/g), Th (24.1 μg/g), and rare earth elements (509.62 μg/g). The concentration of Nb and Ta in the No. 11 Coal is higher than the industrial grade, and their potential utilization should be further studied. Besides pyrite, quartz, calcite, and clay minerals, trace minerals including chalcopyrite, marcasite, siderite, albite, mixed-layer clay minerals of illite and smectite, monazite, apatite, anatase, chlorite, and gypsum were found in the No.11 Coal. It should be noted that alabandite of hydrothermal origin and anatase occurring as cement were identi- fied in coal. In addition, the clayey microbands derived from alkaline volcanic ashes were identified in the coal. The dominant compositions of these clayey microbands were mixed-layer clay minerals of illite and smectite, which were interlayered with organic bands. The modes of occurrence of alkaline volcanic ash bands indicate that the volcanic activities were characterized by the multiple eruptions, short time interval and small scale for each eruption during peat accumulation. The alkaline volcanic ashes were the dominant factors for the enrichment of alkaline elements, Nb, Ta, Zr, Hf, and rare earth elements, and the sulfide minerals are the main carriers of Ga, Cu, and Hg in the No. 11 Coal.

重庆地区二叠系龙潭组煤系地层非常规气地质特征分析

为探索重庆地区二叠系龙潭组煤系地层非常规气地质特征,基于区内煤田勘查、煤层(系)气勘查取得的地质资料及测试数据,对二叠系龙潭组煤系地层煤储层、暗色泥页岩储层、致密砂岩储层基本特征进行分析总结。研究表明,区内煤储层具有煤体结构以碎裂—块状为主、埋深中等、孔隙不发育、低孔低渗、含气量高的特点;暗色泥页岩储层具有低脆性、单层厚度薄、孔隙不发育、低孔低渗、含气量一般的特点;致密砂岩储层具有单层厚度薄、孔隙不发育、低孔低渗、含气性一般的特点。若考虑组合开发,具备一定的开发前景。

宁东煤田二叠纪煤岩煤质特征及清洁利用研究

以宁东多年以来煤田地质勘查资料为主要依据,分析研究了宁东煤田二叠纪煤岩煤质特征。研究结果表明,宁东煤田二叠纪煤层宏观煤岩特征主要为半亮煤和半暗煤,次为光亮煤和暗淡煤;宁东煤田二叠纪煤具有中等灰分、特低-低硫、特低-低磷、特低氯、高发热量等特征,可作为清洁动力煤;同时具有中等-中高挥发分、中-强黏结性、中等含量镜质组的特征,在选煤和降灰后可作为炼焦配煤。宁东煤田中,建议红墩子矿区清洁利用方向为清洁动力用煤、炼焦配煤、干煤粉气流床煤气化用煤;建议横城矿区清洁利用方向为清洁动力用煤、炼焦配煤、干煤粉气流床煤气化用煤;建议韦州矿区清洁利用方向为清洁动力用煤、炼焦配煤、干煤粉气流床煤气化用煤、水煤浆气流床煤气化用煤;建议四股泉矿区清洁利用方向为清洁动力用煤、干煤粉气流床煤气化用煤。

承压水作用下回采巷道底板突水危险性评价研究

华北石炭二叠纪煤系是我国重要的含煤地层之一,煤系底部奥陶系及石炭系岩溶承压水严重威胁煤矿的生产安全。本文以吴桂桥煤矿受承压水威胁的回采巷道为背景,分别采用“岩梁法”和“岩柱法”开展了巷道底板突水危险性评价。“岩梁法”评价巷道底板含水层不具有底板承压突水风险。而“岩柱法”评价结果显示:L_(6)灰岩具有隔水层破坏型突水的危险性,L_(4)灰岩具有一定的隔水层破坏型突水的风险,奥陶系灰岩不具有底板隔水层破坏型突水的风险。在煤矿生产过程中,建议做好巷道底板承压突水的预防措施,保证安全生产。

黔西龙场井田含煤岩系沉积环境及聚煤规律

在研究区野外实测剖面及钻孔岩芯资料分析的基础上,运用沉积相分析、沉积地球化学分析的基本理论及方法,对龙场井田晚二叠世含煤岩系的岩相类型、硫分特征、沉积特征进行了综合的探讨,得到了本区沉积环境及聚煤规律的相关认识。结果表明,东吴运动控制了含煤岩系沉积基底的演化,为含煤岩系的沉积提供了基本的沉积格架。成煤期构造活动相对较为稳定,基底的沉降速率与泥炭或煤层的堆积速率较为平衡,形成了一定厚度的含煤岩系。沉积环境依次经历了潮坪-潟湖、三角洲平原、潟湖-潮坪沉积体系,最有利的聚煤环境为位于三角洲平原上的分流间湾及分流河道,其次为受海水影响较为强烈的潟湖、潮坪环境。

Discovery and geological knowledge of the large deep coal-formed Qingyang Gas Field, Ordos Basin, NW China

After 50 years of oil and gas exploration in Longdong area of southwest Ordos Basin,NW China,a deep coal-formed gas field was discovered for the first time in Qingyang area.Through observation of field outcrops and core,analysis of common,cast and cathode thin sections,Ro and other geochemistry indexes,carbon isotope,electron microscope and other supporting tests and analyses,the hydrocarbon generation,reserves formation and reservoir formation characteristics of gas reservoirs at different buried depths in Yishaan slope were examined and compared.The deep gas reservoir has an average buried depth of more than 4200 m,and the main gas-bearing formation is the Member 1 of Lower Permian Shanxi Formation,which is characterized by low porosity,low permeability,low pressure and low abundance.It is believed that hydrocarbon generation in thin seam coal source rocks with high thermal evolution can form large gas fields,high-quality sandstone reservoirs with dissolved pores,intergranular pores and intercrystalline pores can still develop in late diagenetic stage under deep burial depth and high thermal evolution,and fractures improve the permeability of reservoirs.High drying coefficient of natural gas and negative carbon isotope series are typical geochemical characteristics of deep coal-formed gas.The integrated exploration and development method has been innovated,and the economic and effective development mode of gas fields of"dissecting sand body by framework vertical wells,centralized development by horizontal wells"has been formed.The discovery and successful exploration of the large gas field has provided geological basis and technical support for the construction of natural gas fields of 100 billion cubic meter scale in the southwest of the basin,and has important guidance for exploration of coal-derived gas with deep buried depth and high thermal evolution widely distributed in China.

峨眉地幔柱与西南(贵州)晚二叠世成煤条件及成煤区带划分探讨

发生在二叠纪阳新世晚期-乐平世早期的峨眉地幔柱重大地质事件,直接或间接导致了我国西南地区晚二叠世大规模成煤作用。本文基于《中国矿产地质志·贵州卷·煤》的研编工作,阐述峨眉地幔柱事件产生的系列地质环境效应,使中泥盆世—中二叠世陆内断陷盆地转变为晚二叠世有利聚煤的被动大陆边缘盆地,奠定了贵州晚二叠世大规模聚煤的沉积盆地基底,改变了晚二叠世的气候,形成利于植物生长异常繁茂和森林生态环境、为聚煤成煤提供了丰富的木本。进而依据层级结构,将晚二叠世成煤区带划分为Ⅰ级成煤区(聚煤区),Ⅱ级成煤区(含煤区),Ⅲ级成煤区(储煤带),Ⅳ级成煤区(煤田)。

渤海湾盆地黄骅坳陷石炭系-二叠系煤系烃源岩生烃特征研究

近年来,渤海湾盆地探明数个石炭系-二叠系煤系烃源岩供烃的凝析油气藏,展现出可观的勘探潜力。针对研究区烃源岩生烃特征认识不清、勘探方向不明的问题,亟需重新认识煤系烃源岩的供烃能力。为此,以渤海湾盆地黄骅坳陷为研究对象,通过岩心、测井、录井、试油等多元数据统计,基于盆地内构造单元沉积充填特征差异分析,运用盆地数值模拟技术建立沉积单元评价模型,开展黄骅凹陷煤系烃源岩不同岩层的空间展布、生烃潜力与生烃特征综合分析,明确了渤海湾盆地石炭系-二叠系煤系烃源岩生烃模式,并预测了研究区潜山油气有利聚集带。结果表明:黄骅坳陷石炭系-二叠系煤系烃源岩以煤岩为标志层,发育泥岩、炭质泥岩与煤岩3种生烃岩性,其中,泥岩厚度大,连续性强,生烃潜力大;生烃模拟表明,一次生烃以泥岩生油为主,二次生烃以多种烃源岩混合生油生气为主;发育早期沉降型、晚期沉降型与持续沉降型3类生烃模式,持续沉降型与晚期沉降型生烃区对潜山原地油气聚集最为有利。研究成果可为研究区煤系烃源岩供烃的油气成藏理论研究与勘探部署提供技术支撑。

宣威地区燃煤排放颗粒物毒理学及肺癌地质起因研究

云南省宣威市是我国肺癌最严重的地区,该区肺癌发病率和死亡率均居世界首位。对宣威肺癌患者的基因组学研究发现,宣威肺癌具有与众不同的基因特征,是一种与环境相关的独特发病模式。通过综述宣威肺癌的流行特征以及燃煤排放物的污染水平和毒理学特征,并结合二叠纪末期C_(1)煤层的地球化学特征探讨宣威肺癌的地质起因。宣威肺癌主要流行特征表现在,肺癌死亡率男女比接近1.22,女性肺癌死亡率明显偏高。前人研究表明,室内燃煤排放颗粒物的长期、高浓度暴露,是宣威肺癌的主要诱因。综述毒理学研究结果可知,宣威室内燃煤排放颗粒物中的重金属、多环芳烃和微晶石英矿物浓度均高于其他地区,且被证实可能会引起更严重的DNA损伤和细胞破坏。通过对比宣威肺癌死亡率的空间分布和不同煤矿的煤层分布发现,可采煤层包含C_(1)煤的来宾和龙场地区同时也是宣威肺癌的高发地区,推断C_(1)煤的燃烧可能与宣威肺癌高发有关。C_(1)煤作为晚二叠世最后一层煤,成煤期间受二叠纪−三叠纪生物大灭绝事件影响,形成了独特的地球化学特征。高含量的重金属、多环芳烃和微晶石英矿物等潜在致癌物不仅存在于C_(1)煤中,也随着室内燃煤被释放到空气中,并通过呼吸系统进入人体体内,破坏细胞及DNA结构,造成肺阻塞、肺炎等一系列呼吸道疾病,严重的可能导致肺癌发生。

马道头矿区煤矸石热处理特性及综合利用研究

大同二叠纪矿井均为特大型矿井,产煤量大的同时也带来了大量难以资源化利用的煤矸石。为有针对性地利用大同二叠纪矿井马道头矿区煤矸石,利用X射线荧光光谱仪、X射线衍射仪、扫描电子显微镜、BET比表面积分析仪、热重分析仪等分析设备对热处理前后的大同马道头矿区煤矸石的化学成分、矿物组成、微观形貌、孔隙结构及热处理特性进行分析。结果表明:大同马道头矿区煤矸石主要化学成分为SiO2和Al2O3,属于中高级比铝硅型煤矸石,活性激发温度区间在500~700℃,通过利用热重质谱仪分析该矿煤矸石的热处理特性,获得了该矿区煤矸石的活性最佳热处理温度为700℃左右。对马道头矿区煤矸石的理化特性及热处理特性有了全面的了解后,经过分析不同煤矸石利用方向的特点及该矿区煤矸石特性,对马道头矿区煤矸石的资源化利用提出三个利用方向:制水泥掺和料、提取白炭黑和制备陶粒。

豫西晚二叠世煤中稀土元素地球化学特征及指示意义

随着稀土金属在医疗、新材料等高科技领域的广泛应用,其战略地位不断提升。为了探究豫西晚二叠世煤中稀土元素的富集程度、赋存状态以及沉积环境,以河南西部慧祥矿区二_(1)煤的20个煤分层样品为主要研究对象,运用电感耦合等离子质谱仪(ICP-MS)、X射线荧光光谱(XRF)的方法对研究区煤分层样品中稀土元素与常量元素进行测试,探讨了研究区煤中稀土元素的含量特征和富集程度;利用相关性分析和特征参数对样品中稀土元素的赋存状态以及沉积环境进行探讨。结果表明:慧祥矿区二_(1)煤中,稀土元素的质量浓度为35.29~133.61μg/g,平均浓度为79.14μg/g,略高于世界煤中稀土元素的平均浓度,但明显低于中国煤中稀土元素的平均浓度,稀土元素含量偏低,且以轻稀土富集为主;慧祥矿区二_(1)煤中稀土元素与灰分(Ad)以及SiO_(2)、Al_(2)O_(3)等主要氧化物呈现明显的正相关,表明稀土元素主要赋存于黏土矿物中;研究区样品中Ce元素和Eu元素负异常,(Gd/Gd)_(N)^(*)的轻微正异常,说明研究区主要受陆源的影响,成煤环境为弱酸性的还原环境。