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1.
准格尔煤田含煤岩系高岭岩资源丰富,高铝矿物来源备受关注。采用高分辨率电感耦合等离子质谱等技术对石炭-二叠系太原组6号和山西组4号煤夹矸及顶底板中的稀土元素进行分析,并探讨了其物质来源。结果表明,6号煤夹矸及顶底板中稀土元素总量（ΣREY）均值为167.69μg/g,接近上地壳ΣREY值（168.4μg/g）;4号煤夹矸及顶底板中ΣREY均值为210.22μg/g,高于上地壳的ΣREY值。4号煤夹矸及顶底板中轻稀土含量均值与6号煤相当,中稀土和重稀土含量均值为6号煤两倍以上。6号煤夹矸及顶底板分层样中δCe为0.82～0.94,δEu为0.53～0.87;4号煤中δCe为0.88～0.98,δEu为0.74～0.97;均为Ce、Eu负异常。6号煤层夹矸及顶底板稀土元素主要来源于盆地北西侧阴山地区元古界花岗岩和北东侧下古生界沉积岩。4号煤层夹矸及顶底板稀土元素物源主要为盆地北侧阴山地区下古生界和元古界的沉积岩和火成岩系。  相似文献   

2.
Total 138 coal samples and 14 parting samples were taken from the No. 6 Seam of the Jungar Coalfield, Inner Mongolia. These samples were analysed by optical microscopy, sequential chemical extraction procedure (SCEP), inductively coupled plasma mass spectrometry (ICP-MS), X-ray powder diffraction (XRD), and scanning electron microscope in conjunction with an energy-dispersive X-ray spectrometer (SEM-EDX) analysis. The results indicate that the Li contents have reached the industrial grade of the coal associated Li deposit, and the total Li reserves have reached 2406600 tons, that is, 5157000 tons Li2O in the No. 6 seam in the Jungar Coalfield. The sequential chemical extraction procedure results suggest that the Li concentration is mainly related to inorganic matter. The minerals in the coals consist of kaolinite, boehmite, chlorite-group mineral, quartz, calcite, pyrite, siderite and amorphous clay material. Some Li could be absorbed by clay minerals in the Li-bearing coal seam. The chlorite phase?could be?most likely the host for a part of Li. The Yinshan Oldland should be the most possible source of Li of the coal.  相似文献   

3.
近年来,煤矿区用煤矸石回填、碾压后作为建筑地基基础得到了广泛的应用。以徐州沛县某矿煤矸石新鲜样品和回填多年的矸石(1#、2#)样品为例,对煤矸石的颗粒组成、矿物成份及其胀缩性进行分析,结果发现:新鲜矸石颗粒在10mm以上的含量较大,而1#、2#矸石颗粒级配在10mm以下的含量相对较大;煤矸石岩性成份主要为砂岩和泥岩,矸石样品中的粘土矿物有高岭石、绿泥石、伊利石、伊蒙混层和蒙脱石等,新鲜煤矸石中I/M混层和伊利石的含量与1#、2#矸石相比明显高出许多,因而具有较大的膨胀性;1#、2#矸石膨胀性很小,但是在遇水情况下仍具有一定的膨胀性。对煤矸石地基的破坏机理及作用过程进行了分析,并提出用矸石作地基基础时应注意的问题,认为采取适当的措施煤矸石回填地基作为建筑地基是安全可行的。  相似文献   

4.
晋北煅烧高岭土用煤矸石的应用矿物学特征   总被引：1，自引：0，他引：1  
为了给晋北煅烧高岭土用煤矸石的评价和开发利用提供科学依据,采用XRD、XRF、SEM和白度计等现代分析测试技术,研究了晋北煅烧高岭土用煤矸石的应用矿物学特征。结果表明:1)根据造纸和涂料用煅烧高岭土的国家标准,晋北煤矸石主要可分为3种类型:合格原料、基本合格原料和不合格原料。2)与合格和基本合格原料相比,不合格原料煅烧产物的化学成分中SiO2、Al2O3、Fe2O3含量以及碱金属与碱土金属总含量都与前者有较大差异。3)合格和基本合格原料主要由高岭石(85%~94%)组成,不合格煤矸石矿物组合为高岭石(30%~60%)+石英(23%~38%)+伊利石(14%~26%),并含少量黄铁矿和白云石等杂质矿物,石英等杂质矿物和含铁矿物是分别导致煅烧产物化学成分和白度不合格的主要原因。4)合格原料中高岭石结晶度较好,主要为不规则片状、书册状和弯曲片状,片表面光滑,片径大小范围较大,为0.05~51.22μm,平均2.80μm,径厚比41.24。  相似文献   

5.
This paper mainly describes mineralogy and geochemistry of coals from the Weibei coalfield in the southeastern Ordos Basin, North China. A number of Al-hydroxide/oxyhydroxide minerals were detected in the Late Carboniferous coals (Nos. 5, 10 and 11 coals), especially in the No. 10 coal. Aluminum-hydroxide/oxyhydroxide minerals (nordstrandite, boehmite and diaspore) in the No. 10 coal are associated with kaolinite, suggesting that these minerals are derived from the breakdown of kaolinite. A model in which Al-hydroxide/oxyhydroxide minerals form from the incongruent dissolution of kaolinite is presented. Nordstrandite and boehmite mainly occur as massive lenses (<500 μm in length). Diaspore appears as massive aggregates and as single euhedral crystals (<50 μm in length) in a kaolinite matrix. The presence of high temperature quartz, and zircon indicates that there was input of felsic volcanic debris during accumulation of the Late Carboniferous coals. These volcanic materials have also had a significant influence on the enrichment of certain trace elements including Li, Be, Ga, Zr, Nb, Mo, Sn, W and U in the Late Carboniferous coals (Nos. 5, 10, and 11 coals). SEM-EDX results show that Ga in the No. 10 coal (whole coal average 33.4 μg/g; n = 2) mainly occurs within Al-hydroxide/oxyhydroxide minerals (nordstrandite, boehmite, and diaspore), kaolinite and organic matter.  相似文献   

6.
The mineralogy of the high-volatile bituminous coals and associated strata from the Greta seam, Sydney Basin, Australia, has been evaluated in this study. Although the seam is not immediately overlain by marine strata, percolation of marine water into the original peat bed is indicated by the petrological, mineralogical and geochemical characteristics, which resemble those of coals with marine roof strata. The upper and lower sections of the seam have contrasting mineralogy. Pyrite typically comprises 40 to 56 wt% of the mineral assemblage in the marine-influenced upper part of the seam section. The lower part contains much less pyrite (typically <5 wt%, organic-free basis), and also relatively abundant dawsonite (up to 14 wt%, organic-free basis). The minerals within most coal plies are largely of authigenic origin. These include pyrite, siderite, clay minerals (mainly kaolinite and Na-rich mixed-layer illite/smectite), and quartz, most of which have a relatively early, syngenetic origin. Minor Ti-bearing minerals, anatase or rutile, and phosphate minerals, fluorapatite and goyazite, were probably also formed during early diagenesis. Other minerals have features that indicate late-stage precipitation. These include abundant cleat- and fracture-filling dawsonite, which may be the result of reactions between earlier-precipitated kaolinite and Na2CO3- or NaHCO3-bearing fluids. Minor albite may also be epigenetic, possibly precipitated from the same Ca–Al bearing fluids that formed the dawsonite. The most abundant detrital minerals in the Greta coals are quartz, poorly ordered kaolinite, illite and mixed-layer illite/smectite (I/S). These occur mainly in the floor, roof and other epiclastic horizons of the seam, reflecting periods of greater clastic influx into those parts of the original peat-forming environment. Detrital minerals are rare in the coals away from the epiclastic horizons, probably owing to almost complete sediment bypassing in the depositional system. Alternatively, any detrital minerals that were originally present may have been leached from the peat bed by diagenetic or post-diagenetic processes.  相似文献   

7.
我国球粘土应成为独立矿种,湖沼球粘土中含“内胶体”的自生高岭石是生物有机质作用造成,水云母、I-M间层粘土矿物及有机质会增加可塑性、粘结性及干燥强度,钾、钠的增加可降低烧结温度。沉积球粘土与残积成因高岭石为无序或较无序,古生代煤系高岭石为有序和高度有序,岩浆热液成因的高岭石常为有序或高度有序;北方古生代软质粘土（紫矸）为规模较大、较为均匀稳定的高度有序高岭石,应积极开发。硬水铝石岩溶铝土矿应属于生物有机质成矿作用的沉积型铝土矿。  相似文献   

8.
近年来美国和智利等国家新发现了大量赋存在粘土岩中的锂资源,该类锂资源主要是由火山灰蚀变而成。火山灰沉积水解形成的绿豆岩,广泛分布于我国西南地区,其是否存在锂的富集现象值得研究。笔者对重庆铜梁地区绿豆岩开展了调查研究,通过X射线荧光光谱仪和等离子质谱仪分析,发现绿豆岩中钾的平均含量为8.77%,锂的含量可达663×10~(-6),相当于0.14%的Li_2O含量,远高于固体、露采盐类矿的边界品位0.06%;稀土元素总量可以达到500×10~(-6),接近离子吸附型矿的边界品位。X射线衍射分析显示绿豆岩主要含有石英、长石和粘土矿物,其中粘土的主要成分为伊蒙混层和少量伊利石。伊蒙混层含量占比高的样品较占比低的样品Li的含量偏高。结合粘土及锂的物理化学特性,推断绿豆岩中的Li呈离子形态被粘土矿物吸附。如果这些锂资源能够被综合利用,势必将会产生巨大的经济效益。  相似文献   

9.
Chemical analyses of high-temperature coal ashes were used to establish the distribution, association and relationship between major inorganic elements such as Si, Al, Ti, Fe, Mn, Mg, Ca, Na, K, P, S and CO2 in a number of New South Wales economic coal seams and to study the composition and character of mineral matter in these coals. The methods used for the evaluation of the data were statistical analysis (univariate and bivariate), ratios, normative mineral composition and variation diagrams.The distribution of major and minor inorganic elements in coal appears to be related to the amount of mineral matter occurring in coal (determined as ash yield) and its mineralogical composition. The quantitative variations in levels of these elements can be classified as in-seam and inter-seam variations. In-seam variations are largely ash yield dependent, i.e. the levels of an element (wt.%) in coal increase along with the increase of its ash content (wt.%). The inter-seam variations are more complex and are related to both ash yield and to the mineralogical composition of mineral matter.The principal components of New South Wales coal ashes are silicon and aluminium. Silicon may be present as silica or combined with aluminium in different proportions to form clay minerals, such as kaolinite, illite, mixed-layer clay minerals, and smectite. Thus, the concentration levels of aluminium in relation to silicon in coal may give an indication about the character of clay minerals present in coal.Ratios and correlation coefficients of element pairs such as Al and Ti, Na and K, and Na and Al were used to determine differences in the chemical composition of high-temperature coal ashes of seams from various stratigraphic positions and provinces. In some seams the nature of associations of these elements is more significant than in others. This is interpreted as being a product of specific environmental conditions controlling the deposition of these seams.The nature of clay mineral content in coal is believed to be a major reason for chemical dissimilarities found between seams of various stratigraphic levels and geographic areas. For example, in some seams kaolinite, in others expandable clay minerals are dominant. The vertical distribution of these minerals has a stratigraphic significance. Within the Upper Permian Newcastle Coal Measures a trend from kaolinite-rich through to expandable minerals-rich and to kaolinite-rich assemblages can be observed from the bottom to the top. These changes are noticeably gradual.All significant variations in the clay mineral assemblages could relate to the long-term changes in the provenance of sedimentary material, weathering conditions in the source area and the rate of subsidence in the place of deposition. These changes are associated with major tectonic events controlling the history of sedimentation within the paralic Sydney and Gunnedah Basins during the Permian.  相似文献   

10.
在X射线衍射和扫描电镜观测的基础上,结合区域沉积演化分析,探讨了晋城矿区粘土类型、组合特征、微观结构与沉积-成岩作用的关系。结果表明,晋城矿区粘土矿物以高岭石为主,其次为伊利石和伊利石/蒙脱石混层,还有少量的绿泥石和蒙脱石;山西组粘土矿物颗粒排列定向性优于太原组,多呈带状或平叠状产出,而太原组多为蜂巢状、花朵状或凝絮状;由于太原期频繁的海侵海退致使煤层顶底板处于pH值较高的碱性环境,使成岩过程中高岭石向伊利石转化,造成太原组粘土矿物的伊利石含量明显高于山西组,而高岭石含量相对较低。  相似文献   

11.
This work focuses on the relationship between the coal deposition and explosive volcanism of the Miocene basin, NW central Anatolia, Turkey. The coal-bearing Hirka Formation was deposited over the Galatian Andesitic Complex and/or massive lagoonal environments during the Miocene. The investigated lignite is a high ash (from 32 to 58%) and sulphur (from 1.43 to 3.03%) lignite which is petrographically characterised by a high humunite content. The mineral matter of the studied lignite samples is made up of mainly clay minerals (illite-smectite and kaolinite), plagioclase and quartz in Bolu coal field, clay minerals (illite-smectite, smectite and illite), quartz, calcite, plagioclase and gypsum in Seben coal field, quartz, K-feldspar, plagioclase and clay minerals (kaolinite and illite) in K?br?sc?k, and dolomite, quartz, clinoptilolite, opal CT and gypsum in Çaml?dere coal field. The differences in these four types of lignite with specific mineralogical patterns may be due to the explosive volcanic events and depositional conditions which changed from one coal field to the others. There is a zonation from SW to SE in the studied area for zeolites such as Opal CT+smectite-clinoptilolite-analcime-K-feldspar. Carbonate minerals are commonly calcite in Seben and K?br?sc?k coal fields. In Bolu, coal samples are devoid of calcite and dolomite. These analyses show that there is an increase in the amount of Mg and a decrease in the amount of Na from the northwestern part to the southern part in the study area.  相似文献   

12.
深部煤系软岩遇水崩解的宏观特征及微观机理研究   总被引：1，自引：0，他引：1  
      随着煤层开采层位的加深,对煤系软岩水稳性的研究越来越重要。巨野3号煤顶底板岩层以泥质岩为主,赋存深度900～1200 m,为典型的深部煤系软岩。通过水理性试验、X射线衍射试验及电镜扫描试验,对巨野煤田深部煤系软岩遇水崩解的宏观特征及微观机理进行分析研究。研究发现软岩水稳性较差,浸水后在30 min内开始崩解;岩样粘土矿物以高岭石及蒙伊混层为主,结构上表现为明显的疏松性及定向排列性。通过分析认为深部煤系软岩崩解是粘土矿物内外膨胀联合作用的结果,其中软岩结构特征是导致该类岩石遇水崩解的主要因素。  相似文献   

13.
Chemical differences in the composition of high-temperature coal ashes of major economic seams of the Sydney Basin were studied using a normative analysis. All chemical data were recalculated to normative mineral assemblages consisting of: quartz, kaolinite and illite. Quartz and clay minerals, the principal constituents of mineral matter occurring in coals, account for most of the variations found in the chemical composition of high-temperature coal ashes between seams of various stratigraphic levels and/or geographic locations. Ternary diagrams based on the quantitative relation of quartz, kaolinite and illite were used to demonstrate these differences.  相似文献   

14.
通过X射线衍射系统分析了杭州湾地区SE2孔全新世沉积物的黏土矿物组成,结果显示研究层段黏土矿物主要由伊利石、绿泥石、高岭石和蒙脱石组成;伊利石结晶度较好,化学风化指数普遍大于0.5,表明以化学风化为主,且风化趋势自下而上呈递减趋势。通过对比中国东南部主要河流沉积物的黏土矿物组成,认为钱塘江下切河谷全新世沉积物的黏土矿物组成具有较好的物源指示意义: 全新世 Ⅰ 段(即古河口湾和河漫滩)沉积物主要来自钱塘江上游,特征黏土矿物为高岭石,河口外物质贡献不大;Ⅱ 段(即现代河口湾和近岸浅海)沉积物包含较多蒙脱石,表明不仅包括钱塘江上游物质,河口外长江物质也开始进入钱塘江河口。黏土矿物中,高岭石对气候有较好的指示作用:中全新世高岭石含量达到最高值,反映气候最为湿热,化学风化程度最高;晚全新世含量逐渐降低,反映气候逐渐回冷,化学风化强度降低。  相似文献   

15.
海陆过渡相煤系泥页岩广泛分布,具有良好的天然气资源潜力。以淮南煤田煤系泥页岩为研究对象,运用X射线衍射、扫描电镜等分析手段,对淮南煤田煤系地层泥页岩的矿物学、岩相、储层特征等方面进行相关测试,并探讨了泥岩岩相对页岩气储集空间的控制作用。研究表明:淮南煤田煤系泥页岩矿物成分中黏土矿物含量多、自生非黏土矿物相对较少,致使岩石脆性降低并对压裂裂缝产生具有负效应,但部分菱铁矿的存在可能起改善作用;存在花斑状高岭石泥岩、浅灰色高岭石泥岩、鲕状泥岩、暗色泥岩、粉砂质泥岩等5种岩相。泥页岩储层裂缝包括层面剪切缝、有机质演化异常压力缝、层间页理缝、构造裂缝等宏观类型和与石英和高岭石有关的微裂缝类型;泥页岩孔隙包括化石孔、粒间孔、粒内孔和晶间孔及可能的有机质孔等类型,为页岩气赋存提供了储集空间。不同沉积环境下的泥岩岩相不同,进而决定了矿物成分特征与有机质相对含量,对泥页岩储集空间起主要控制作用。  相似文献   

16.
测水煤系是湖南分布较广、储量丰富的含煤地层之一。对于结构简单,灰份较低的煤层,可以通过异常明显的自然伽马低异常与伽马伽马高异常加以判别。但在结构复杂、挤压破坏强烈、薄煤分层、夹矸与顶底围岩炭化程度高、煤与围岩及夹矸物性差异小等情况下,仅靠自然伽马与伽马伽马等常规测井方法难以满足测井质量验收标准。以浆江勘探区3909孔、3503孔及金竹山矿区7403孔为例,利用伽马伽马短源距、三侧向、声速及密度等测井方法,结合常规自然伽马与伽马伽马测井,较好地解决了复杂结构煤层的定性、定厚问题,取得了较好的地质效果。  相似文献   

17.
湘中下石炭统粘土矿物组合特征   总被引：1，自引：0，他引：1  
湖南中部下石炭统是一套以碳酸盐岩为主夹碎屑岩含煤岩系的沉积,根据粘土矿物在下石岩统剖面分布规律,结合各组段岩性岩相特征,可推断出粘土矿物组合特征及其环境分布,从滨岸碎屑沉积到滨外泥质陆棚、滨外浅水碳酸盐陆棚,到深水碳酸盐陆棚和浅海盆地,即从滨岸向盆地方向,高岭石含量急剧减少,伊利石逐渐增加,伊利石/蒙脱石混层矿物和绿泥石则先是增加,然后又趋于减少,其最高含量分别在浅水碳酸盐陆棚和滨外泥质陆棚。测水组含煤岩系粘土矿物以高岭石为主,伊利石次之,并有一定量的绿泥石和伊利石/蒙脱石混层矿物,它们在垂向上的变化反映了沉积环境水介质酸碱度和盐度的变化规律。  相似文献   

18.
Chromium contents obtained from 20 coal and 5 associated rock samples collected from the basal part of the Eocene Chuckanut Formation, in Skagit and Whatcom counties, northwest Washington, range between 30 and 300 ppm (mean 120 ppm whole-coal basis). The lenticular coals, ranging in rank from subbituminous to anthracite, and with an ash content of 12–46%, crop out along the western flank of the Cascade Range. Results of X-ray diffraction analysis of low-temperature ash show that the mineral matter in the coal samples consists predominantly of quartz and clay (kaolinite, illite and chlorite group). However, accessory minerals, isolated from the coal samples and analyzed by X-ray diffraction, scanning electron microscope and optical methods, contain angular fragments and euhedral crystals of the spinel group (chromite, magnetite and trevorite ), kaolinite-serpentine group (antigorite and chrysotile), chlorite group, amphibole group and pyroxene group minerals (augite, diopside and enstatite), all of which are commonly enriched in chromium.Although associated primarily with the inorganic fraction of the coal, concentrations of chromium in the samples show no statistically significant correlation with ash content. Localized concentrations of chromium in the coal are the result of natural contamination from the alteration of detrital chromium-bearing mineral grains introduced into the peat-forming mires from nearby Jurassic ophiolite bodies. The coals formed in the early Eocene, in rapidly subsiding small basins that developed during the uplift and erosion of the pre-Tertiary ophiolite terrain. Scattered bodies of source rock, random distribution of chromium-bearing minerals within the coal and sample heterogeneity account for the variation in Cr contents of the samples.  相似文献   

19.
李晋  任大伟 《岩石学报》1989,5(3):76-85
老石旦矿区的高岭土(木节土)呈灰白、灰紫及灰黑色,质地松软,可塑性高,是一种良好的耐火材料和陶瓷原料。对其成因过去有两种看法:(1)原生沉积的;(2)由煤层风化淋滤形成的。作者认为是煤层风化残积形成的。即煤层经地壳运动抬升到地表以后,受到强烈的风化淋滤作用,使有机组分分解,流失和逸散,铝硅矿物相对富集,在表生条件下形成木节土。  相似文献   

20.
Industrial uranium orebodies have recently been found through in-depth uranium exploration in the Luohe Formation in the southwestern Ordos Basin, which is an important breakthrough in deep prospecting for sandstone-type uranium deposits. The composition, content and characteristics of clay minerals in the Luohe Formation in the Zhenyuan area were systematically studied by means of thin section identification, scanning electron microscopy, X-ray diffraction and altered mineral spectral scanning. Unlike the most important uranium-bearing rock series in the Zhiluo Formation in the northeast and southwest of the basin, the ore-bearing Luohe Formation sandstone has low contents of clay minerals while the clay mineral assemblages vary in different sand bodies. Among them, the main types of mudstone, oxidized sandstone, calcareous sandstone and mineralized sandstone are illite-smectite mixed-layer mineral and illite, followed by kaolinite and chlorite, the main types uranium-rich sandstone and gray-green sandstone are kaolinite and illite-smectite mixed-layer mineral, followed by illite and chlorite. Even though adsorption of clay minerals, such as chlorite, illite-smectite mixed-layer mineral, kaolinite, and illite may contribute to U enrichment and uranium mineral precipitation, no correlation between clays and uranium minerals have been observed, indicating that clay minerals are not the main factor affecting uranium enrichment during the deep metallogenic process. The study of clay minerals in the Luohe Formation sandstone demonstrated that there are at least two phases of chlorite and one phase of kaolinite in the study area, which respectively represent two phases of alkaline fluid and one phase of acid fluid activities, revealing a fluid phase transition of alkaline-acidic-alkaline. Therefore, the clay minerals can be used as an important indicator for uranium mineralization. © 2020, Science Press. All right reserved.  相似文献   

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