从煤的变质程度看夹矸转化

通过研究无烟煤层中泥岩夹矸的岩石矿物学特征,探讨了其主要成分高岭石发生转化的主要方向及影响因素。通过样品的显微镜下鉴定、差热分析、X射线粉晶衍射分析、红外吸收光谱分析等一系列测试结果的分析研究,发现无烟煤层泥岩夹矸中高岭石因受不同因素的影响而发生不同的转化,即:高岭石向伊利石转化,伊利石-蒙脱石(I/M)混层矿物及蒙脱石出现。其主要原因是区域变质作用及周围介质影响所致。     

无烟煤泥岩夹矸的岩石矿物学特征及其研究意义

对山西晋城矿区3号无烟煤层进行了实地观测，采集了一定数量的标本，通过显微镜下鉴定、差热分析、X射线粉晶衍射分析、红外吸收光谱分析等一系列测试手段对无烟煤层中泥岩夹矸的岩石矿物学特征进行了研究，对其主要成分高岭石发生变化的主要原因及影响因素进行了探讨。结果发现，无烟煤层中泥岩夹矸的主要成分高岭石因受不同因素的影响而向不同方向发生转化，主要表现在高岭石向伊利石转化，并有伊利石-蒙脱石(I/S)混层矿物及蒙脱石出现。造成这种煤的变质程度升高而其夹矸成分转化的主要原因可能是区域变质作用及周围介质条件影响所致。     

山西晋城和阳泉地区石炭系太原组铵伊利石矿物特征及成因

铵伊利石是伊利石层间域的K+被NH+4替代而形成的类质同象.文中运用X射线衍射分析、傅里叶红外光谱分析以及热重—热流—红外光谱同步分析等手段,对山西晋城及阳泉地区的15号煤层夹矸及煤中矿物进行了研究,发现15号煤层夹矸和煤低温灰中黏土矿物以铵伊利石和高岭石为主,铵伊利石含量为21％～74％;X射线衍射图谱上d(001)...     

华北地区京西煤田侏罗纪煤层中伊利石矿物学特征及成因

为了探讨伊利石对煤化作用和沉积环境的指示作用，以华北地区京西煤田侏罗纪煤层夹矸为研究对象，采用X射线衍射方法（XRD）和X射线荧光方法（XRF）分别测定煤层夹矸的矿物组成和化学组成，研究夹矸中伊利石矿物学特征及成因。结果表明，京西煤田侏罗纪煤层夹矸主要由伊利石、绿泥石和石英组成，其中，伊利石质量分数平均为62.92%。将XRD数据和XRF数据进行对比分析，计算得到伊利石平均化学式为（K_0.37（NH₄）_0.03）Al₂（Si_3.60Al_0.40O₁₀）（OH）₂。京西煤田煤层夹矸中伊利石主要由高岭石转化而来，伊利石的NH₄+占层间阳离子的比例具有随沉积古盐度升高而逐渐升高的趋势，n（Si）/n（Al）Ⅳ具有随煤化程度升高而逐渐降低的趋势，这表明京西煤田侏罗纪煤层夹矸中的伊利石矿物学特征对沉积环境和煤化作用具有一定的指示作用。      

准噶尔盆地南缘侏罗系泥岩黏土矿物组合及地球化学特征

对准噶尔盆地南缘玛纳斯河剖面泥岩中黏土矿物的组合类型、微观形貌和地球化学特征进行了综合分析,讨论了侏罗纪古气候、古环境演化过程。结果表明,泥岩中主要矿物为黏土矿物、石英、长石,以及少量的方解石、赤铁矿等。黏土矿物组合类型分为两类。一类为伊利石-蒙脱石混层矿物、伊利石、高岭石和绿泥石组合,主要分布在下侏罗统泥岩中;另一类为伊利石和蒙脱石组合,主要分布在上侏罗统泥岩中。扫描电子显微镜分析表明,黏土矿物结晶度较低,伊利石常呈丝状、叶片状,蒙脱石呈不规则板状分布在碎屑颗粒表面,片状伊利石/蒙脱石混层矿物存在于孔隙之中。其δCe为0.9~1.3,Eu呈负异常,La/Sc、La/Th、Th/Sc值则较高,指示源区母岩为长英质岩石类型。研究认为准南地区侏罗纪气候和沉积环境演化可划分为3个阶段:早侏罗世属于温暖湿润气候条件,以湖泊-三角洲沉积为主;中侏罗世早期属于温干偏湿润气候条件,以湖泊沉积为主;中侏罗世中后期至晚侏罗世属于相对较冷干旱的气候条件,属于宽浅氧化湖盆沉积环境类型。     

蒙脱石伊利石化的水热实验模拟

以蒙脱石为初始材料,通过水热实验模拟在不同温度压力条件下蒙脱石的伊利石化过程。利用X射线粉末衍射及X射线荧光光谱、红外光谱和扫描电镜等方法对样品的矿物物相、化学成分、晶体结构与微观形貌等进行分析,其结果表明:(1)蒙脱石至伊利石的转化受温度和压力条件的控制;(2)随着温度和压力的增高,蒙脱石伊利石化沿着蒙脱石-无序伊蒙混层-有序伊蒙混层-伊利石的转化序列进行转化;(3)水热实验模拟表明蒙脱石至伊利石的转化以溶解重结晶机制为主。实验结果不仅有助于了解埋藏与低级变质作用中的蒙脱石伊利石化过程,同时为研究断层活动所致断层泥中黏土矿物的转化及反演断层形成时温度压力条件提供基本参数。     

滇东磷矿床中粘土矿物的研究

滇东磷矿床中粘土矿物分布比较广泛,在震旦系到寒武系各地层中均有分布。本文仅讨论下寒武统渔户村组中谊村段磷矿层夹层及顶、底板页岩中的粘土矿物。经化学分析、X射线衍射、红外吸收光谱分析、差热分析及电子显微镜分析,确定长区磷矿床中的粘土矿物主要是伊利石和伊利石/蒙脱石不规则混层矿物,其次为高岭石、变埃洛石,含少量海绿石。通过对混层矿物的研究,为本区矿物间的转化、沉积环境及成岩作用的探讨提供了重要的资料。     

松辽盆地F油层高岭石、伊利石对储层物性、敏感性影响的实验研究

松辽盆地F油层砂泥岩互层发育,高岭石、伊利石为其主要粘土矿物,对研究储层物性及该油层的有效开发具有重要意义。本文通过对F油层90块天然岩心的室内研究发现,F油层渗透率、孔隙度随着高岭石相对含量的增加而增加,随着伊利石相对含量的增加而减小。砂岩层渗透性较好,高岭石相对含量较高,次生石英很少就地沉积,大量长石溶蚀孔隙得以保存;泥岩层渗透性差,伊利石相对含量较高。而且伊利石纤维状赋存和高岭石书页状赋存使砂岩层孔渗性更好,而使泥岩层孔渗性更差。该层开发过程中,高岭石、伊利石对储层物性的影响由室内岩心流动实验可知,F油层为中等强度偏弱速敏、中等强度偏强碱敏,速敏指数随着高岭石、伊利石绝对含量的增加而增加;储层的碱敏指数随高岭石绝对含量的增加而增加,而与伊利石含量无关。由于在所有粘土矿物中,高岭石相对含量接近一半,所以在F油层的开发过程要注重防范高岭石的碱敏、速敏损害。     

湖南测水组粘土矿物组合及其环境意义

测水组粘土矿物主要为高岭石及伊利石,其次为少量绿泥石、叶腊石及伊利石一蒙脱石混层矿物。它们在垂向上具有一定变化规律,与沉积环境的演化相一致。泻湖及演浅海沉积中粘土矿物主要为伊利石和绿泥石.潮坪、淡水泻湖及沼泽沉积中主要为高岭石,其次为伊利石。     

鲁西南煤夹矸的矿物学特征研究及应用前景

对鲁西南上石炭统11层煤和7层煤夹矸的化学成分和矿物学特征进行了研究，结果表明，这两层煤夹矸属于硬质高岭土，成分接近于纯净的高岭石，伴生有石英、黄铁矿、少量长石及微量锆石和磷灰石等矿物。光学及扫描电子显微镜、X射线衍射分析和红外分析等系统性研究的结果表明，高岭石主要有两种存在形式，一种呈蠕虫状集晶，另一种是隐晶质或胶状高岭石，测得其结晶指数分别为0．54—0．74和0．47—0．53，说明其有序度偏高；化学分析结果表明，其化学成分接近于高岭石的理论值，A1203含量达35％—37％，Si02含量为47％—48％，碱金属、碱土金属及其他氧化物含量很低。高岭石泥岩夹矸的矿物、化学成分及工艺物理性能表明：它是一种开采成本低、利用价值高的高岭土资源之一，不仅可作为优质陶瓷原料用来生产长石质瓷，也可用于生产聚合铝及4A分子筛，并且在矿物填料和其他工业部门也有广阔的开发应用前景。     

高岭石泥岩夹矸的焙烧相变特征和深加工应用

通过热分析、X射线衍射分析对高岭石泥岩夹矸焙烧相变特征规律进行研究，阐述了深加工工艺方法，并重点研究了4A分子筛的合成工艺路线和在塑料中的应用性能。高岭石泥岩夹矸的脱羟温度大于600℃，说明其有序度高。高岭石在加热分解为偏高岭石的过程中衍射峰是逐步消失的。对高岭石泥岩深加工工艺包括超钦细和改性(包覆、接枝、乳液聚合)、化学处理等方法，焙烧工艺非常关键，先超细再焙烧，可大大降低了能耗。由高岭石泥岩合成4A分子筛，因其具多孔结构和特殊的晶体形态，可显著提高重质碳酸钙在塑料中的分散性，具有固体分散剂的特征，故可用于塑料中以提高期料产品件能。     

An Upper Carboniferous tonstein of volcanic origin

Previous work on the mineralogy of the volcanic supra-Wyrley Yard tonstein is extended to include the opaque minerals. This has led to a better understanding of the major and trace element geochemistry of the tonstein. The complete mineral assemblage is kaolinite (dominant) with minor quartz, K-mica, zircon, apatite, pyrite, sphalerite, galena, rutile, dolomite, barytes, goethite and organic matter. Information on element location in the tonstein has been obtained by using autoradiography and fission track radiography, the electron probe and by analysing separated fractions with an optical spectrograph. This has enabled the diagenetic history of individual elements to be determined, and the composition of the tonstein to be compared with igneous material. The high concentration of Th, U, Pb, Sn, Bi, Y, Be and B in the tonstein, and the low concentration of Ti, Cr, V, Ni, Cu and Co is indicative of an acidic ash. A source in the Armorican orogenic belt is postulated, based on the contrast with the basaltic Carboniferous volcanism and also the high concentrations of Sn, Pb and Zn.     

Resources of Kaolinite Rocks in China Coal Measures

The kaolinite rocks are very abundant in China coal mea-sures,most of which are very pure,excellent and in goodquality for industrial use.The geological feature,occurrence,origin and processing techniques are largely different fromthose of the traditional kaolins.The kaolinite rocks in Chinacoal measures are marvelous,but a large-scale kaolinite de-posit is rare in the world.The origin of kaolinite rocks in thecoal measures is under debate for a long time(Liu and Zhang,1 997;Liang,1 995;Boho…     

Absolute Dating of Permian Ash-Fall in the Rio Bonito Formation,Paraná Basin,Brazil

The Rio Bonito Formation in southern Paraná basin contains a set of tonsteins interbedded with coal-seams. These tonsteins are composed mainly of kaolinite with zircon, apatite and beta-quartz paramorphs as accessory minerals, and were interpreted as volcanic ashes deposited by ash falls over pits protected by barrier islands in a barrier-lagoon system. A U-Pb dating of zircons in the tonstein A, which furnished an age of 267.1 ± 3.4 Ma (Early Permian) confirming previous age-dates based on palynology and correlating them with one of the main periods of volcanic activity in the Gondwana.The source of the pyroclastic material was attributed to the early Permian Choiyoi magmatic arc in Argentina, developed during the Sanrafaelic orogeny, and with a main peak of volcanic activity between 260 and 272 Ma.     

大青山巨厚煤层夹矸中高岭石的显微特征及其成因意义

本文采用多种电子显微技术,研究了内蒙古大青山煤田晚古生代巨厚煤层平矸－隐晶质高岭石泥岩。透射电镜下,晶体程序不一、形态复杂多变的玻屑状高岭石和盘旋状埃洛石;扫描电镜下,泥粒状高岭石和蠕虫状高岭石及及二者所构成的斑状结构等许多具成因意义的微有（０．１～１０－μｍ）显微特征,充分证明该夹矸层为火山灰蚀变成因（ｔｏｎｓｔｅｉｎ）。     

A geochemical and mineralogical investigation of some British and other European tonsteins

The volcanic origin of a number of major tonstein horizons has been established from mineralogical compositions and from trace elements that are quantitatively retained during diagenesis. Discriminant function analysis using the variables Ti/Al, Cr/Al, Zr/Al and Ni/Al allows the tonsteins to be classified according to original composition. Two main groups are recognized amongst the British tonsteins. Those formed from acid volcanic ash are comparable in composition with French and German tonsteins and a common source is postulated, whereas tonsteins formed from basic volcanic ash contain variable amounts of detrital sediment and are thought to originate from local eruptions. Possible lateral equivalents between tonstein horizons in Britain and elsewhere in Europe are suggested.     

Origin and distribution of tonsteins in late permian coal seams of Southwestern China

We have surveyed the areal and stratigraphic distribution of tonsteins in Late Permian coalfields of southwestern China over an area of several hundred thousand square kilometers. We studied the relationship between tonstein distribution and sedimentary environment. Based on mineralogical and petrographic data, we have concluded that these tonsteins originated as air-fall volcanic ashes. Following accumulation in the peat swamps, in situ alteration of the vitric and lithic components took place under acidic conditions, leading to the formation of kaolinite.Based on petrologic, mineralogic, and chemical analytical data, we have determined that the application of mineralogic and geochemical criteria for tonsteins may be useful in correlating coal beds, predicting coal qualities and reconstructing related sedimentary paleoenvironmental conditions.     

Element mobility during alteration of silicic ash to kaolinite—a study of tonstein

A laterally persistent kaolinitic mudstone parting (tonstein) occurring in a Wyoming coal bed of Eocene age was sampled to estimate the compositional contrast with a probable silicic ash precursor, and to determine the compositional influence of leached ash on immediately adjacent coal. With the exception of Al, and possibly Ti, the tonstein is highly to moderately leached of major elements, relative to a range of compositions estimated for silicic ash of the region. In agreement with the behaviour of geochemically similar major elements, alkali trace elements (Rb, Cs) are highly leached, transition-series metals moderately leached, and Ga is residual. Additional immobile trace elements are Zr and Hf but some other trace elements that are considered relatively immobile during low-temperature alteration (Th, Ta, Nb, REE, Y) were apparently leached by the low-Eh, low-pH, organic-rich pore fluids of the coal-forming swamp. The migrational range of many of the leached elements is highly limited by the intimate association of tonstein with enclosing organic matter. Mixtures of coal + minor tonstein that occur within 20 mm of contacts are consistently enriched in some elements relative to either tonstein or nearby coal (U, Cu), or relative to calculated mixtures of tonstein and coal in their measured proportions (Th, Y, REE, Pb, Ba, V, Ti). Direct observations by fission-track radiography and electron microprobe indicate a preference of U and Fe for the organic component of mixtures. Metal fixation is probably by adsorption on insoluble organic matter (humic acids), or by precipitation as minor sulphides in these low-sulphur coals.