geochemical and mineralogical evidence for a coal hosted uranium deposit in the yili basin xinjiang northwestern china abstract the petrological geochemical and mineralogical compositions of the coal hosted jurassic uranium ore deposit in the yili basin of xinjiang province northwestern china were investigated using optical microscopy and field emission scanning electron microscopy in conjunction with an energy dispersive x ray spectrometer as well as x ray powder diffraction x ray fluorescence and inductively coupled plasma mass spectrometry the yili coal is of high volatile c b bituminous rank 0 51 0 59 vitrinite reflectance and has a medium sulfur content 1 32 on average fusinite and semifusinite generally dominate the maceral assemblage which exhibits forms suggesting fire driven formation of those macerals together with forms suggesting degradation of wood followed by burning the yili coals are characterized by high concentrations of u up to 7207 g g se up to 253 g g mo 1248 g g and re up to 34 g g as well as as up to 234 g g and hg up to 3858 ng g relative to the upper continental crust the rare earth elements rees in the coals are characterized by heavy or and medium ree enrichment the minerals in the yili coals are mainly quartz kaolinite illite and illite smectite as well as to a lesser extent k feldspar chlorite pyrite and trace amounts of calcite dolomite amphibole millerite chalcopyrite cattierite siegenite ferroselite krutaite eskebornite pitchblende coffinite silicorhabdophane and zircon the enrichment and modes of occurrence of the trace elements and also of the minerals in the coal are attributed to derivation from a sediment source region of felsic and intermediate petrological composition and to two different later stage solutions a u se mo re rich infiltrational and a hg as rich exfiltrational volcanogenic solution the main elements with high enrichment factors u se as and hg overall exhibit a mixed organic inorganic affinity the uranium minerals pitchblende and coffinite occur as cavity fillings in structured inertinite macerals selenium as and hg in high pyrite samples mainly show a sulfide affinity

anomalies of rare metals in lopingian super high organic sulfur coals from the yishan coalfield guangxi china abstract the origin and modes of occurrence of rare metals in coal e g rare earth elements u se re ge ga and nb have attracted much attention in recent years because such investigations can provide fundamental information for assessment of their economic significance this paper investigates the abundance modes of occurrence and origin of rare metals in three lopingian coals ll5 k3 cg3 k6 and cg1 k7 coals from the yishan coalfield guangxi province southern china the coals of this coalfield are preserved within carbonate successions and are characterized by super high organic sulfur shos contents mostly 6 9 and an elemental assemblage enriched in u se mo v re two different hydrothermal solutions were responsible for the geochemical anomalies in the yishan coals one was responsible for the u se mo v re enrichment in the three coal seams while the other was a high temperature solution responsible for the positive eu anomalies and the elevated rank r o ran 2 05 of the ll5 k3 coal the u se mo v and re in the cg3 k6 and cg1 k7 coals mainly have an organic association but the same elements in the ll5 k3 coal have a mixed organic inorganic affinity attributed to high temperature leaching in the early coalification stage in addition to highly elevated concentrations of u se mo v re the average concentration of oxides of the rare earth elements and y in the ll5 k3 coal 1387 ppm on average ash basis is higher than the cut off grade for industrial deposits of these elements and thus the coals also have potential as raw materials for the recovery of rare earth elements

coal deposits as promising alternative sources for gallium abstract gallium ga which is a rare valuable metal has been found to be anomalously enriched in coal to the extent that it may be considered as an economic resource recovery of ga from coal or coal combustion byproducts offers a promising alternative way to obtain this metal and such techniques could probably lead to economic gains and positive impacts on the environment thus geochemical research and technical investigations of ga bearing coal would be helpful in assessing the potential for economic extraction of the ga the present review of ga in coal focuses on analytical methods that can be used to determine ga concentrations patterns of ga enrichment in coal and formation of economic ga enriched coal deposits modes of occurrence of ga and its origins the behavior of ga during coal combustion and gasification and currently available recovery techniques for ga moreover insufficiencies in previous research are identified and future research needs regarding ga in coal are evaluated and discussed

geochemistry of radioactive elements u th in coal and peat of northern asia siberia russian far east kazakhstan and mongolia abstract geochemistry of radioactive elements in more than 5000 coal and peat samples of northern asia has been investigated by quantitative methods such as the instrumental neutron activation analysis the method of delayed neutrons and the x ray fluorescence analysis the average u content in the coals of deposits and basins of the region ranges from 0 6 to 32 8 ppm and for th from 0 8 to 9 2 ppm within the boundaries of basins deposits and some coal beds lateral and vertical changes of the distribution of radioactive elements have been studied the high concentrations of u and th in coal deposits are spatially related to rock blocks within the basin frames which are enriched in elements or are connected with a volcanism of a period of coal formation a consistent changing of the role of pyroclastic material in the radioactive elements accumulation was determined in the direction from the west to the east

geochemistry and nano mineralogy of feed coals mine overburden and coal derived fly ashes from assam north east india a multi faceted analytical approach abstract in order to address the scarcity of information on the nature and mode of occurrence of minerals and elements in coal coal mine overburden and coal ashes from north east india and also the relations between coal mineralogy and ash chemistry the petrology mineralogy and nano mineralogy and ash chemistry of some industrially important high sulfur coals mine overburden materials and fly ash samples from assam india have been evaluated a combined approach using petrography low temperature ashing plus x ray diffraction lta xrd field emission scanning electron microscopy fe sem high resolution transmission electron microscope hr tem raman spectroscopy and inductively coupled plasma mass spectrometry icp ms has provided new information on the mineralogy and nano mineralogy of these sub bituminous coals and associated mine overburden the presence of rare earth elements and yttrium rey in northeast indian coal mine overburden and fly ash samples is also reported for the first time the identification of these components may be significant from an economic point of view some northeast indian fly ashes with ree oxides up to 1580 ppm on an ash basis might possibly represent sources for recovery of rare earth elements

factors controlling geochemical and mineralogical compositions of coals preserved within marine carbonate successions a case study from the heshan coalfield southern china abstract the late permian coals in the heshan coalfield of southern china are preserved within marine carbonate successions and characterized by super high organic sulfur 5 13 10 82 minerals identified in the coals include quartz kaolinite illite mixed layer illite smectite albite pyrite marcasite calcite and dolomite along with trace amounts of smectite fluorite strontianite rey bearing carbonate minerals jarosite and water bearing fe oxysulfate the coals are very rich in trace elements including f up to 3362 g g v up to 270 g g se up to 24 4 g g mo up to 142 g g u up to 111 g g and to a lesser extent sr y zr nb cd cs heavy rare earth elements hf ta w hg and th previous studies attributed the high organic sulfur and elevated trace elements to the seawater influence or the formation of soil horizons before the accumulation of peat in the basin however mineralogical and geochemical data presented in this study have shown that the sediment source region and multi stage hydrothermal fluids are the dominant influences on the mineralogical composition and elevated trace elements in the coal although seawater influence also contributed to the composition of the mineral matter for example a large proportion of the quartz and clay minerals as well as almost all the albite in both the coal benches and the parting mudstones were derived from detrital materials of terrigenous origin in the yunkai upland high concentrations of lithophile trace elements were also derived from the sediment source region minerals including fluorite calcite dolomite strontianite and rey bearing carbonate minerals were derived from multi stage hydrothermal activities high concentrations of v mo and u that occur through the coal seam sections were probably derived from hydrothermal solutions during peat accumulation or at the early diagenetic stages the hydrothermal fluids also corroded the syngenetically formed minerals quartz albite and pyrite and caused re distribution of lithophile elements from partings to the underlying coal benches resulting in higher key element ratios yb la nb ta and zr hf and more abundant heavy rare earth elements in the coal benches than in the immediately overlying partings

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

origin of minerals and elements in the late permian coals tonsteins and host rocks of the xinde mine xuanwei eastern yunnan china abstract this paper reports the mineralogical and geochemical compositions of the late permian c2 and c3 coals both medium volatile bituminous coal from the xinde mine near xuanwei in eastern yunnan which is located close to the area with the highest female lung cancer mortality in china the two coals are characterized by high ash yields and low sulfur contents three factors including sediment source region multi stage volcanic ash generation and multi stage hydrothermal fluid injections were responsible for variations in the geochemical and mineralogical compositions of the xinde coals trace elements including v sc co ni cu zn se zr nb hf and ta are enriched in the coals and were mainly derived from the sediment source kangdian upland region major minerals in the samples of coal roof floor and non coal sediment partings include quartz kaolinite and chamosite as well as interstratified illite smectite and anatase chamosite in the coal was derived from reactions between kaolinite and fe mg rich hydrothermal fluids however chamosite in the roof strata was directly precipitated from fe mg rich hydrothermal fluids or was derived from the alteration of precursor minerals e g biotite by hydrothermal fluids quartz in some samples is very high especially in the roof strata of the c2 and c3 coal such high quartz along with minor minerals including pyrite chalcopyrite sphalerite calcite celestite vanadinite barite clausthalite and silicorhabdophane were derived from multi stage hydrothermal fluids the floors of both the c2 and c3 coal seams are fully argillized fine grained tuffaceous claystone and the immediate roof of the c2 coal is argillized coarse grained tuff the original materials of the floors and roofs of these coal seams were high ti alkali basaltic volcanic ashes as indicated by high tio 2 nb and siderophile elements and the distribution patterns of rare earth elements two intra seam tonstein layers in the c3 coal were identified based on their lateral persistence mineralogical mode of occurrence and composition as well as their elemental composition the tonsteins are dominated by kaolinite with minor quartz and possibly mixed layer illite smectite both tonsteins were derived from dacitic magma the ratios of nb ta zr hf and u th are much lower in tonsteins than in the adjacent coal benches which is attributed to the hydrothermal leaching

a model for nb zr ree ga enrichment in lopingian altered alkaline volcanic ashes key evidence of h o isotopes abstract clay altered volcanic ash with highly elevated concentrations of nb ta zr hf rare earth elements ree and ga is a new type of critical metal deposit with high commercial prospects that has been discovered in yunnan province southwest china previous studies showed that the volcanic ashes had been subjected to hydrothermal fluids the nature of which however is not clear here we show that the volcanic ashes were originated from alkaline magmatism followed by a continuous hydrothermal weathering process heated meteoric waters which were sourced from acidic rains and mixed with co2 from degassing of the emeishan plume have caused partial but widespread acidic leaching of nb ta zr hf ree and ga into ground water and residual enrichment of these elements along with al and ti in the deeply altered rocks subsequent alteration occurring under cooler neutral or alkaline conditions caused by water rock interaction resulted in precipitation of the leached critical metals in the deposit polymetallic mineralization of similar origin may be found in other continental regions subjected to explosive alkaline volcanism associated with deep weathering in humid conditions

trace elements geochemistry of the dobrudza coal basin bulgaria abstract the paper discusses the abundance mode of occurrence and origin of trace elements in the dobrudza coal deposit the deposit is the deepest in bulgaria it is overburden by paleozoic up to cenozoic sediments of 1300 m to 1600 m thickness the coal rank reaches the stage of high volatile a bituminous coal the contents of ba cl br mn ge pb w mo as zr li cs cu zn sb ti v th u ag be and y are enriched from 1 5 to 9 2 times as compared with the clarkes for bituminous coals the content of the other elements are slightly higher lower than the respective world wide means chondrite normalized patterns of the ree reveal a strong fractionation among the hree and lree most pronounced for the coals than for the coaly shales and partings a specific feature is the small eu anomaly in the shales and the tonsteins underlying the coal bed most elements are of mixed organic and inorganic association ge cl br mo be and au are predominantly bound to the organic matter arsenic correlates strongly with fe suggesting presence in pyrite ba occurs mainly as barite which is most probably of epigenetic origin sr and mn are presented mainly as isomorphous admixtures in barite and calcite the abundance of the lithophile elements excluding ge mo ba cl br is controlled largely by the detrital and clay mineral content of the coals many elements of different groups correlate positively each other calculation of partial correlation coefficients excluding ash shows that many of these correlations are spurious due to the positive correlation of every single element with ash for this reason the correlation coefficients must be critically evaluated when deducing the mode of occurrence of elements the accumulation of the trace elements in the dobrudza coals was influenced by multi component geological factors 1 as a result of upper pennsylvanian volcanism there are widespread tonsteins underlying the coal layers and as thin layers in the coal most likely many elements were leached from the tonsteins and trapped by the coal 2 olivinobasalt and andesito basalt dikes intruding the coal bearing sediments may cause enrichment or depletion of many elements 3 highly mineralized underground waters are the source of cl br b sr and probably some other elements 4 the numerous regional faults favor the penetration of solutions of different origin which were carriers of trace elements 5 postgenetic erosive processes may cause leaching of trace elements from the rocks which are consequently fixed by the coal

mineralogical composition of late permian coal seams in the songzao coalfield southwestern china abstract coals from three seam sections in the songzao coalfield sw china are mainly high ash high sulphur semianthracites minerals within the songzao coals are mainly kaolinite pyrite or marcasite in some cases and quartz with various proportions of non kaolinite clay minerals carbonates feldspars and anatase the illite and mixed layer illite smectite i s are na rich in some of the datong coal samples the i s in the lower coals of the datong section is most likely an alteration product of dispersed volcanic ash due to the availability of necessary ions e g k na and mg in the marine influenced coal swamp organically bound na which was expelled from the organic matter with coal rank advance especially with anthracitization may have supplied additional na for the formation of na rich illite authigenic i s also occurs in a tonghua coal ply that is overlain by a mafic bentonite and underlain by an alkali tonstein potassium na and mg for the formation of such i s were probably derived from the leaching of the adjacent alkali tonstein and mafic bentonite although the marine water was also a possible supplier of the alkali elements authigenic i s is rare in coal plies that occur further away from the altered volcanic layer leaching of the volcanic claystones in the tonghua coal seam probably led to the formation of relatively abundant anatase and rhabdophane in the underlying coal ply fracture filling ree minerals probably ree hydroxides or oxyhydroxides also occurring in that coal ply crystallized from ascending ree rich hydrothermal fluids probably associated with contemporaneous volcanic activity

forensic petrology and geochemistry tracking the source of a coal slurry spill lee county virginia in october 1996 coal slurry blew out from a mine portal in lee county virginia precipitating a fish kill and pollution of streams leading to the tennessee river the petrology and geochemistry of two slurries associated with coal mine portals including the pollution source and preparation plant fines associated with one of the mines were investigated maceral content and in particular microlithotype content distinguished the sources differences in concentrations of zr y and the lanthanides provided a subtle set of parameters for distinguishing between the sources owing to the source of one mine slurry and the plant slurry from a coal known to have an enrichment in those elements

distribution of rare earth elements in eastern kentucky coals indicators of multiple modes of enrichment abstract four eastern kentucky pennsylvanian coals from oldest to youngest the manchester pond creek fire clay and hazard coals were examined for their total rare earth element rey concentration and the possible mechanisms for enrichment of the rare earths based on previous studies four possible modes are considered terrigenous tuffaceous infiltrational and hydrothermal with the dean coal a correlative of the fire clay coal considered to be a typical example of the tuffaceous mode the fire clay owes much of its high rey content to the presence of a volcanic ash fall tonstein with rey bearing zircon and phosphates in the coal in numerous locations some of the original rey elements may have components of the detrital minerals deposited in the peat leaching of rey from the tonstein into the surrounding coal and the hydrothermal overprint of mineralizing fluids associated with the northwestwardly movement of the pine mountain thrust sheet contributed to the total rey signature in the fire clay coal not all coals are going to have the complex history of the fire clay coal but it should be considered that the total history of rey enrichment by multiple mechanisms is what gives us both the total rey concentration and the relative distribution of the individual lanthanide elements

arsenic and lead concentrations in the pond creek and fire clay coal beds eastern kentucky coal field abstract the middle pennsylvanian breathitt formation westphalian b pond creek and fire clay coal beds are the 2 largest producing coal beds in eastern kentucky single channel samples from 22 localities in the pond creek coal bed were obtained from active coal mines in pike and martin countries kentucky and a total of 18 fire clay coal bed channel samples were collected from localities in the central portion of the coal field the overall objective of this study was to investigate the concentration and distribution of potentially hazardous elements in the fire clay and pond creek coal beds with particular emphasis on as and pb 2 elements that are included in the 1990 clean air act amendments as potential air toxics the 2 coals are discussed individually as the depositional histories are distinct the fire clay coal bed having more sites where relatively high s lithologies are encountered in an effort to characterize these coals 40 whole channel samples excluding 1 cm partings were analyzed for major minor and trace elements by x ray fluorescence and proton induced x ray emission spectroscopy previously analyzed samples were added to provide additional geographic coverage and lithotype samples from one site were analyzed in order to provide detail of vertical elemental trends the as and pb levels in the fire clay coal bed tend to be higher than in the pond creek coal bed one whole channel sample of the fire clay coal bed contains 1156 ppm as ash basis with a single lithotype containing 4000 ppm as ash basis most of the as and pb appears to be associated with pyrite which potentially can be removed in beneficiation particularly coarser pyrite disseminated finer pyrite may not be completely removable by cleaning in the examination of pyrite conducted in this study it does not appear that significant concentration of as or pb occurs in the finer pyrite forms the biggest potential problem of as or pb enriched pyrite is therefore one of refuse disposal

rare earth elements and yttrium in pennsylvanian coals and shales in the eastern part of the illinois basin abstract the objective of this study was to evaluate rare earth elements and yttrium rey concentrations in pennsylvanian coal bearing strata in the eastern part of the illinois basin indiana specifically targeting coals and marine shales associated with the coals samples were collected from several coal mines and three boreholes in total 105 samples were analyzed using inductively coupled plasma optical emission spectrometry icp oes including 69 coals 31 shales and 5 paleosols concentrations of rey in the coals vary from less than 200 ppm to more than 3000 ppm on ash basis indirect evidence including rey versus ash relationships rey distribution patterns and rey content in raw coal compared to that in washed coal suggests that the organic association may be an important mode of rey occurrence in these coals the lower block and the upper block coal members of the brazil formation and some coals of the staunton formation have the highest rey concentrations among those studied concentrations of rey in marine shales range from less than 200 to 800 ppm on ash basis the majority of shale samples studied vary little from the rey values of the continental crust but some show enrichments our results suggest that while post combustion coal ash of the high rey coals are a potential source of these elements significant efforts and resources are needed to make the studied shales a viable rey resource

mineralogy of the pennsylvanian coal seam in the datanhao mine daqingshan coalfield inner mongolia china genetic implications for mineral matter in coal deposited in an intermontane basin abstract this paper deals with the mineral matter in the coal and associated strata from the datanhao mine daqingshan coalfield which is closely located to the previously reported adaohai and hailiushu mines of the same coalfield the coal from the datanhao mine is mainly high ash and low sulfur bituminous the mineral assemblage in the coal is dominated by quartz kaolinite with varying proportions of carbonates calcite ankerite and siderite small proportions of muscovite illite pyrite and anatase the associated non coal claystone samples have similar mineral assemblage except that most non coal samples contains less quartz than the adjacent coal plies although deposited in the same intermontane basin of the orogenic belt the yinshan upland the datanhao coal seam shows different mineralogical characteristics from those of the nearby adaohai and hailiushu mines this may reflect the different sediment source regions during the peat accumulation stage the sediment source for the datanhao coal was probably the ordovician quartz rich sandstone or the sinan quartzite in the surrounding sub uplifts high proportions of quartz in the datanhao coal suggest intense terrigenous input into the paleomire and a short distance from the sediment source region different mineralogical characteristics of the coals from the three mines datanhao hailiushu and adaohai of the daqingshan coalfield are probably due to the different source material in their respective surrounding subuplifts within the intermontane basin kaolinite displaying graupen tabular and vermicular textures and the common presence of quartz in the intra seam non coal bands from the datanhao coal seam indicate that most of these bands are tonsteins altered airborne volcanic ash the original magma is probably high level volatile rich silicic in composition

an appalachian isochron a kaolinized carboniferous air fall volcanic ash deposit tonstein the fire clay tonstein is a kaolinized airfall volcanic ash bed that was deposited in a widespread late carboniferous peat forming mire eleven samples from kentucky and west virginia spanning a distance of 200 km and two samples from tennessee and virginia indicate a characteristic mineralogical signature as compared with other appalachian tonsteins consisting of well crystallized kaolinite beta quartz crystal paramorphs sanidine ilmenite zircon and brookite detrital illite and quartz are rarely present or are in very small amounts which indicates rapid deposition in a mire several normal graded cycles in this tonstein suggest repeated episodes of pyroclastic activity that produced a composite ash layer a high silica alkalic rhyolitic source is suggested by the geochemistry of immobile elements and by electron probe analyses of glass inclusions in volcanic quartz from the fire clay tonstein the rare earth element plots chondrite normalized of the tonstein show a pronounced negative eu anomaly and relatively high concentrations of zr and th which are both indicative of a rhyolitic source probe analyses of the fire clay glass inclusions from four states indicate a chemically identical high silica rhyolite with peraluminous affinities 40 ar 39 ar sanidine plateau dating indicates an age of 312 1 ma for the fire clay tonstein which is consistent with previous 40 ar 39 ar dates for this tonstein this age is in agreement with a late westphalian b age in the european carboniferous chronostratigraphy on the basis of an age of 311 ma for the westphalian b c boundary a new isopachous map of the fire clay ash fall deposit indicates an area of 37 000 km 2 and a probable source to the present day southwest the deposit has a minimum preserved compacted volume of 2 8 km 3 which corresponds to an original uncompacted volume of about 20 km 3 this preserved volume indicates an ultraplinian volcanic explosion pindell and dewey 1982 proposed an andean type arc in this block during the late carboniferous prior to south american north american plate collision we hypothesize an associated back arc caldera system in the yucatan block to explain the high silica potassic rhyolitic ash that gave rise to the fire clay tonstein

paleoecology of the fire clay coal bed in a portion of the eastern kentucky coal field vertically continuous increment samples of the fire clay coal bed mid middle pennsylvanian late westphalian b collected from a portion of the central appalachian basin were studied palynologically petrographically and geochemically in order to partially reconstruct the paleoecology and processes associated with peat formation in the ancient fire clay paleomire results indicate that four compositional groups can be identified they are 1 a lycospora vitrinite dominant group characterized by high percentages of lycospora and vitrinite macerals and generally low but variable ash yields and sulfur contents 2 a mixed palynoflora high vitrinite group that petrographically is similar to group 1 except that it contains a more diverse palynoflora 3 a mixed palynoflora moderate low vitrinite group characterized by various admixtures of lycopsid fern and calamite miospores increased percentages of liptinite and inertinite macerals and low ash yields and sulfur contents and 4 a mixed palynoflora high ash yield group characterized by high percentages of small lycopsid fern and occasionally calamite and cordaite miospores high liptinite and inertinite contents high ash yields and moderate to high sulfur contents the fire clay coal bed contains a distinctive flint clay parting of probable volcanic origin that naturally divides the bed into two benches these two benches upper and lower are highly disparte in occurrence appearance and composition in the study area the lower bench generally is thin 0 5 m laterally discontinuous and mainly composed of dull mainly durain coal lithotypes ash yields typically are high sulfur contents generally are moderate to high compositional group 4 the mixed palynoflora high ash yield group defines all of the increments examined from the lower bench in contrast the upper bench is thick 0 75 m laterally continous and mainly comprised of bright mainly clarain coal lithotypes overall ash yields and sulfur contents for this bench are generally low although vertical variation is apparent all of the compositional groups occur in the upper bench in some columns notably those that are thick and uninterrupted by clastic partings groups 1 and 4 often occupy basal coal layers and groups 2 and 3 occur in higher layers other columns especially those taken in areas of thin 0 5 m fire clay coal are dominated by groups 1 and 4

analysis origin and significance of mineral matter in coal an updated review abstract the material classed as mineral matter in coal embraces crystalline mineral materials as well as a range of inorganic elements that occur in non crystalline form this review outlines the methods that may be used to evaluate the percentage of mineral matter for a coal sample as opposed to the ash yield and to identify the minerals their individual percentages and their modes of occurrence within the coal the principal techniques include low temperature oxygen plasma ashing quantitative evaluation of x ray diffraction data observation using optical microscopy and a combination of observation chemical analysis and in some cases mapping based on scanning electron microscopy and related methods a range of other techniques may also be used to provide additional information on particular mineral matter components processes responsible for mineral matter formation include detrital input biogenic activity and authigenic precipitation at different stages of the coal s depositional and post depositional history differential migration of non mineral inorganic elements may also occur in lower rank coals and expulsion of non mineral inorganics may take place with rank advance knowledge of the mineral matter may be of assistance in understanding the modes of trace element occurrence with implications for assessing possible environmental impacts and also the potential for recovery of economic products from coal the behaviour of different mineral matter components at high temperatures is also discussed as well as methods for mineralogical analysis of ashes and other coal utilization products information from mineral matter studies may provide an improved basis for understanding coal formation and for evaluating the response of particular coals to different combustion gasification and coking processes

comments on the geochemistry of rare earth elements la ce sm eu tb yb lu with examples from coals of north asia siberia russian far east north china mongolia and kazakhstan abstract the geochemistry of the ree la ce sm eu tb yb and lu is reviewed with supporting data from coals of north asia the 7189 samples from north asia included in this study represent all coal ranks lignites subbituminous coals bituminous coals and anthracites as well as coals formed under different geotectonic regimes and in different sedimentary conditions these coals are characterized by higher contents of the ree as compared to the coal clarke the distribution characteristics and accumulations of the ree have been studied in several coal deposits and basins within some basins with the near background average contents of the ree isolated coal beds enriched in lanthanides have been observed in coal basins and deposits the relative enrichment in the lanthanides are observed in the fields or zones adjacent to the source area of the terrigenous material accumulation of high ree contents in coal deposits can be attributed to the presence of rocks in the source area containing high concentrations of ree and also alkaline or acidic volcanic ash contemporaneous with the peat accumulation in the basin transformation of volcanic ashes under the aggressive hydro environment of a peat bog results in the mobilization and redeposition of the ree adjacent to the altered volcanic ashes tonsteins with the formation of high concentrations of ree in the coal beds the formation of the ree anomalies may also be related to hydrothermal processes the modes of occurrence of the ree change during the coalification process brown coals with a low degree of coalification are dominated by the organic modes of occurrence of the ree whereas in hard coals and anthracites authigenic mineral forms dominate

rare earth minerals in a no tonstein section of the dean fire clay coal knox county kentucky abstract the dean fire clay coal in knox county kentucky does not contain the megascopically visible ash fall tonstein present in most other sections of the coal bed like the fire clay tonstein a low ash portion of the coal is enriched in rare earth elements 2400 ppm on ash basis in addition to kaolinite produced in the diagenesis of volcanic glass transmission electron microscopy studies indicate the coal contains primary kaolinite la ce nd th monazite barium niobate native gold and fe ni cr spinels the mineral assemblages particularly the kaolinite monazite association and its similarity to the tonsteins in coal to the east demonstrate the coal was subject to the ree enriched volcanic ash fall apparently just at a more dilute level than at locations where the tonstein is present

magnetotellurics study to identify subsurface resistivity structure in the eastern part of kachchh little rann area of gujarat india a magnetotelluric mt survey has been conducted in the eastern part of the kachchh region of gujarat state crossing little rann starting from adesar village in the north to enjar village in the south where limited geophysical data is available the profile has been acquired in the n s direction having a total length of 52 km with the interstation spacing of 3 4 km from two dimensional 2d inversion of the mt data four conductive zones are identified the analysis reveals that the depth of the basement varies from 1 2 km in the south to 1 8 km in the north the first conductive zone is found at a distance of 3 km in the south of adesar and is identified at the location of the kanmer fault kf the eastern extension of south wagad fault swf and might be the kf the second conductive zone is found at a distance of 42 km in the south of adesar and 13 km north of enjar village and is located at the contact zone of kachchh and saurashtra peninsula at the location of the north kathiawar fault nkf it is inferred as the nkf the third conductive zone at a distance of 27 km in the south of adesar is found between the first and second conductor this is interpreted as a step fault formed during the rifting process of kachchh the lower crust below 20 km is found conductive 120 m and might indicate the presence of fluid filled mafic ultramafic rocks in the lower crust

geochemistry of the pond creek coal bed eastern kentucky coalfield the pond creek coal bed middle pennsylvanian breathitt formation is an important low sulfur resource in pike and martin countries in the eastern kentucky coalfield the mined area is crossed by the n20 e trending belfry anticline the pond creek coal bed has a higher sulfur content on the west side of the anticline the vertical trends in the ash geochemistry also vary across the anticline the sites to the east of the anticline represent deposition of peat through periods of relative stability with slow deposition bright lithotypes interspersed with periods of relatively rapid clastic deposition dull lithotypes both generally removed from marine influence comparison of elemental trends between the lowest bright lithotype and the second bright lithotype suggest that the swamp became less acidic with time an upward decrease in minor element concentration may be related to the influx of clays and other silicates present in the bone lithotype this bone may have acted as a relatively low nutrient soil for the growth of the plants which contributed to the overlying bright lithotype the sites to the west of the anticline were subjected to a greater marine influence than the eastern sites high k2o al2o3 ratios at the bottom and top of the coal bed and a high tio2 zr dull clarain near the bottom of the coal point to clastic influences on the geochemistry the relatively high cao percentages in the middle third of the coal bed suggest deposition at near neutral ph the upper third of the coal bed was dominated by syngenetic and epigenetic pyrite emplacement

mississippian anthracites in guangxi province southern china petrological mineralogical and rare earth element evidence for high temperature solutions abstract minerals and elements in coal are derived from the processes associated with peat accumulation and rank advance as well as possibly a range of epigenetic processes and thus can provide information on the depositional conditions and geologic history of coal beds and coal bearing sequences as well as perhaps on regional tectonics this paper investigates the petrology mineralogy and geochemistry of anthracites and their host rocks partings roof and floor strata from two coal deposits hongmao and luocheng in guangxi province southern china samples collected from these deposits were analyzed using optical microscopy scanning electron microscopy plus energy dispersive x ray spectrometry low temperature ashing x ray diffraction x ray fluorescence spectrometry and quadrupole based inductively coupled plasma mass spectrometry the anthracites from the two deposits are medium to high sulfur coals the rare earth elements in the luocheng anthracites are characterized by distinct positive eu anomalies and medium and heavy ree enrichment types the minerals in the hongmao anthracites are characterized by the occurrence of k illite paragonite and ammonian illite which however are absent in the luocheng anthracites the paragonite ammonian illite and chlorite resulted from the alteration of pre existing kaolinite by hot solutions containing na nh4 and fe2 respectively the partings in the luocheng anthracite seams contain pyrophyllite that was formed by reactions between kaolinite and quartz during injection of high temperature solutions the mineralogical and geochemical characteristics of the anthracites in the two deposits indicate that the coals were subjected to high temperature 250 c solutions that also elevated the coal rank to anthracite grade the assemblage of k illite paragonite nh4 illite in the coals of the hongmao deposit was formed under greater hydrothermal but less tectonic influence compared to the luocheng deposit by contrast the pyrophyllite illite chlorite assemblage of the luocheng deposit reflects a greater tectonic but lesser hydrothermal influence

distribution of rare earth elements in coal combustion fly ash determined by shrimp rg ion microprobe abstract during coal combustion for electric power generation rare earth elements ree are strongly retained in the ash fraction leading to significant enrichment compared to the ree content of the respective feed coals knowing how the ree are distributed in coal ash is essential to devising effective approaches for ree extraction from this potential resource to better understand the distribution of ree in coal ash we used the stanford usgs shrimp rg ion microprobe to determine grain scale ree partitioning in a suite of 19 u s and international coal fly ash samples shrimp rg microanalysis used a nominal spot size of 15 m and an oxygen negative ion primary beam nist multi element glass standards srm 611 and srm 613 were used for ree calibration prior to shrimp rg analysis samples were characterized by backscattered electron imaging and wavelength dispersive elemental mapping to delineate constituents of interest for ree microanalysis results confirm the occurrence of ree in aluminosilicate glasses consistent with previous results that showed a strong positive correlation between al and ree content in a larger group of u s and international coal fly ash samples among these glasses aluminosilicates consisting of al and si and lacking other major constituents tend to have ree contents similar to or slightly lower than the bulk sample ree content whereas ca and or fe enriched aluminosilicate glasses are similar to or more ree enriched than the bulk sample co occurring quartz and or high silica glass is almost always the most ree depleted fly ash constituent having much lower ree contents than the aluminosilicate glasses fe oxide magnetospheres have ree content with relative proportions of light lree to heavy hree rare earths that are more variable than in the aluminosilicate glasses results suggest that extraction of ree from the aluminosilicate glass fraction in coal ash will yield a significant portion of the ree present and therefore this fraction should be targeted in ongoing efforts to recover ree from coal fly ash

rare earth elements in a sampled coal from the pirin deposit bulgaria abstract rare earth elements la ce sm eu tb yb and lu in a columnar section of the coal of the pirin deposit bulgaria have been determined by neutron activation analyses the ree content in the coals is lower than the average ree content of shales from north america europe and the soviet union the ree abundances increase with the increasing ash content of the coals the bottom of the seam is slightly enriched in ree the trend being more pronounced in hree tb yb lu the ree content depends on the thickness of the coal layers the thin coal layers are enriched in ree as compared to the thick ones the chondrite normalized distribution patterns are very uniform they are characterized by a negative eu anomaly whose mean value is 0 30 varying in the individual samples from 0 21 to 0 49 and a positive lu anomaly it is supposed that the eu anomaly is inherited from the source rocks the shale normalized distribution patterns show a distinct relative enrichment in hree and a negative eu anomaly the relative enrichment in hree is a specific feature of the ree geochemistry in the pirin deposit the lree hree ratio is lower than that of composite shale it increases with the increasing ash content of the coals and from the bottom to the top of the coal bed ree are bound predominantly to the aluminosilicates of the mineral matter in the coals all ree are positively correlated to the ash si al fe and na the source of ree in coals is mainly the suspended terrigenous material the specific enrichment of ree in the ash of low ash coals is a result of the interaction between the dissolved ree and the products of disintegration and decay of organic substances mainly the humic acids

enrichment of critical elements nb ta zr hf ree within coal and host rocks from the datanhao mine daqingshan coalfield northern china abstract this paper discusses the modes of occurrence of critical elements and their origins in the studied coal and associated rock samples partings and roof strata from the datanhao coal mine daqingshan coalfield inner mongolia northern china the studied coals are enriched in trace elements including zr hf th be f zn ga nb mo cd in sn ta hg w pb and rare earth elements and y rey zirconium nb ta and hf are largely associated with anatase in the studied coal and non coal samples the main carriers of rey th and u in both coal and non coal samples are ca bearing ree phosphate minerals most likely monazite although u is partly associated with organic matter fluorine in the datanhao coals is mainly associated with kaolinite most partings identified as volcanic ash derived tonsteins from the datanhao mine exhibit negative eu anomalies that along with the common presence of equant shaped euhedral volcanic quartz beta quartz indicate a felsic volcanic source located in the xing an mongolia orogenic belt other probable sources of clastic material into the basin include the pre cambrian granites from the adjacent uplands which may be responsible for the light rare earth element enrichment of the studied deposits and associated metamorphic rocks from the adjacent uplands owing to acidic hydrothermal fluids which are most likely related to the yanshanian jurassic to early cretaceous intrusive activity and or low temperature basinal waters circulating within the coal bearing unit during the epigenetic stage most of the coal benches from the datanhao mine are also relatively enriched in middle rare earth elements on the other hand some coal and non coal bench samples from the middle datanhao section are enriched in heavy ree this along with the presence of abundant syngenetic or early diagenetic carbonate minerals indicates deposition in an episodic alkaline environment the origin of which is mostly probably attributed to evaporation and or saline water inputs resembling a playa lake environment as the concentrations of zr hf nb and ta are all close to or higher than the respective industry cut off grades or standards for these critical elements the datanhao coal seam has potential economic significance for these as an important by product of the coal mining

lithologic and geochemical investigations of the fire clay coal bed southeastern kentucky in the vicinity of sandstone washouts abstract the fire clay hazard no 4 coal bed of the middle pennsylvanian breathitt formation in eastern kentucky is interrupted by a series of discontinuous sandstone bodies this sand belt which includes two washouts was studied in perry county the coal thickens toward the interruptions and the coal between the sand bodies is highly disturbed several prominent durains in the upper bench of the coal bed are laterally continuous within the study area statistical analysis indicates that the durain layers contribute much of the vertical coal quality variation the sandstone bodies are inferred to be a result of post depositional fluvial activity and the disturbance of the coal between washouts is due to compaction related slumping a thin kaolinite rich lens similar to the flint clay parting was found below the main parting

coal deposits as potential alternative sources for lanthanides and yttrium abstract this paper presents data on widespread abnormal accumulations of lanthanides and yttrium rey in many coal deposits worldwide high rey contents 0 1 have been found in coal seams and coal ashes as well as in the host and basement rocks of some coal basins for a preliminary evaluation of coal ashes as an rey raw material not only the abundance but also the individual rey compositions were taken into account in this paper three rey distribution patterns for high rey coal ashes are fixed with lrey lan lun 1 mrey lan smn 1 and hrey lan lun

arsenic bearing pyrite and marcasite in the fire clay coal bed middle pennsylvanian breathitt formation eastern kentucky abstract arsenic concentrations determined on 11 lithotype samples from the middle pennsylvanian breathitt group fire clay coal bed leslie county ky range from 1 to 418 ppm whole coal basis the 11 lithotype samples which vary in thickness from 4 to 18 cm were sampled from a continuous 1 38 m channel sample and were selected based on megascopic appearance vitrain rich versus attrital rich a lithotype that contains 418 ppm as is located near the top of the coal bed and is composed of 10 5 cm of bright clarain bands containing fusain that within short distances grade laterally into fe sulfide bands to determine the mode of occurrence of as in this lithotype the coal was examined with scanning electron microscopy and analyzed by energy dispersive x ray fluorescence massive framboidal cell filling cell wall replacement and radiating forms of fe sulfide were observed in the high as lithotype many of the radiating fe sulfide forms and one of the cell wall replacements contained as examination of the grains with optical light microscopy shows that the majority of radiating morphologies are pyrite the remainder are marcasite selected fe sulfide grains were also analyzed by electron microprobe microscopy arsenic concentrations within individual grains range from 0 0 wt to approximately 3 5 wt on the basis of morphology these fe sulfides are presumed to be of syngenetic origin and would probably be removed from the coal during physical coal cleaning thus eliminating a potential source of as from the coal combustion process however because the grains are radiating and have high surface area dissolution and release of as could occur if the pyrite is oxidized in refuse ponds

identifying sources of respirable quartz and silica dust in underground coal mines in southern west virginia western virginia and eastern kentucky prior research has suggested that the source of respirable silica dust in underground coal mines is typically the immediate top or bottom lithology adjacent to the mined seam not mineral matter bound within the mined coal bed geochemical analyses were applied in an effort to identify the specific source rock of respirable quartz dust in coal mines the analyses also demonstrate the compositional changes that take place in the generation of the respirable dust fraction from parent rock material all six mine sites were mining coal with relatively low mineral matter content although two mines were operating in the fire clay coal bed which contains a persistent tonstein interpretations of ca mg mn na and k concentrations strongly suggest that the top strata above the mined seam is the primary source of mineral dust produced during mining one site indicates a mixed or bottom source possibly due to site specific conditions respirable dust compositional analyses suggest a direct relationship between the quantity of mineral si and the quantity of quartz si a similar relationship was not found in either the top or bottom rocks adjacent to the mined seam an apparent loss of elemental al was noted in the respirable dust fraction when compared to potential parent rock sources elemental al is present in top and bottom rock strata within illite kaolinite feldspar and chlorite a possible explanation for loss of al in the respirable dust samples is the removal of clays and possibly chlorite minerals it is expected that removal of this portion of the al bearing mineral matter occurs during rock abrasion and dust transport prior to dust capture on the samplers

geological controls on the distribution of rey zr hf nb ta enrichment horizons in late permian coals from the qiandongbei coalfield guizhou province sw china abstract the abnormal enrichment of the rey rare earth elements and yttrium zr hf nb ta assemblage in late permian coals occurring in some coalfields in sw china has been extensively investigated but the geological controlling factors of this assemblage are still under debate this study reports on the mineralogical and geochemical features of coals and noncoal rocks collected from the yudai and jinqi coal mines within the qiandongbei coalfield in guizhou province to elucidate the geological controls on the distribution of rey zr hf nb ta enrichment horizons the studied coals show rather consistent clay mineral assemblage of kaolinite together with varying amounts of quartz gypsum pyrite and calcite notably the coals are anomalously enriched in rey nb ta zr and hf and enriched in other incompatible elements e g ga th and u phosphates e g florencite and to a lesser extent zircon are the primary carriers of rey zirconium and hf are mainly incorporated into zircon and then anatase the latter of which is a predominant carrier of nb and ta the detrital materials originate from a mixture of the erupted felsic volcanic ash resembling a peralkaline rhyolite composition and the eroded materials of emeishan large igneous province elip basalts the studied coals owe their highly enhanced concentrations of the rey zr hf nb ta assemblage to the input of felsic volcanic ash wherein the highly acidic aqueous solutions allowed these elements to become mobile and be redistributed both geological processes governed the distribution of rey zr hf nb ta enrichment horizons the highly acidic solutions were possibly derived from the oxidation of peat bogs and volcanism related acidic rain the concentrations of rey zr and nb in the coal ashes exceed their corresponding cut off grades thus these coals can be considered highly promising raw material sources for the rey zr hf nb ta assemblage

rare earth element bearing coals from the russian far east deposits abstract coal seams up to 10 m in thickness with high rare earth element ree concentrations 300 1000 ppm were detected in some of the russian far east deposits this paper reports on the ree composition of the coals from a number of deposits the ree bearing coals are subdivided into three geochemical types studies of ree distributions across the coal seams examination of gravitation fractions and sem edx studies have revealed that the enriched coals seams contain ree mainly as sorbed forms by organic matter and clay particles and fine grained authigenic minerals the ree coals formed in 1 erosion tectonic depressions with wide spread weathering crusts in their basins and 2 volcano tectonic grabens in which coal accumulation occurred simultaneously with bimodal volcanism in the former case ree are thought to originate from the borderland in the second case from chambers of subalkaline magma the ree accumulation in the organic material occurred mostly during the peat stage due to mineralized ree bearing water coming to the basins the high ree contents up to 1 0 and even more of the combustion wastes their low lree hree ratios and the considerable estimated resources all place the ree bearing coals of the russian far east among new and very promising mineral resources for y and heavy lanthanoids as by products

volcanic ash in the lower cretaceous chaswood formation of nova scotia source and implicationsgeological survey of canada contribution 20100082 lignites and coals because of their low sedimentation rates of terrigenous detritus may preserve a record of volcanic ash fall lignite from the lower cretaceous chaswood formation in central nova scotia was studied to identify whether any volcanic ash is present and can be correlated to known early cretaceous volcanism in southeastern canada and adjacent new england the bulk mineralogy and geochemistry of lignite and lignitic mudstones was determined by x ray diffraction and whole rock geochemical analysis of ashed samples selected samples were examined by electron microprobe and scanning electron microscope much of the terrigenous component of some lignites consists of detrital sediments in some lignites distinctive rare earth element patterns are due to leaching from monazite and concentration in organic matter some lignites however lack illite and or quartz indicative of detrital sources but show unusual abundance of stable high field strength elements such as nb ta and hf suggesting a

geochemistry of late triassic coals in the changhe mine sichuan basin southwestern china evidence for authigenic lanthanide enrichment abstract five thin coals of late triassic age occur in the changhe mine sichuan basin southwestern china petrology and geochemistry of these coals and their roof parting and floor samples were studied the results show that the changhe coals are enriched in as 8 9 11 8 g g w 2 2 11 2 g g pb 20 8 48 2 g g and th 7 5 18 8 g g the source of these elements is possibly the xuefeng old land which is an early paleozoic source area southeast of the sichuan basin two tonsteins were found in the changhe mine one is the roof k8r of the k8 coal which is a pure kaolinitic claystone the other is the claystone k9c above the roof of the k9 coal which is mainly made up of mixed illite smectite minerals the ree content 287 9 g g of the k8 coal is much higher than that of its roof 153 6 g g sem edx results show that authigenic monazite and kaolinite are the main carriers of ree in the k8 coal on the basis of coal chemistry and occurrence of the precipitated minerals it is likely that leaching of the k8r tonstein occurred it is possible that trace elements including be 8 4 g g zr 302 g g nb 26 g g hf 9 7 g g th 18 8 g g u 5 8 g g ga 16 1 g g and pb 48 2 g g in the k8 coal were also elevated by the leachate of its overlying tonstein k8r the k9c tonstein with a total thickness of 16 cm is widely distributed in the changhe mine and serves as a distinct marker bed for correlation of coal seams besides mixed illite smectite minerals trace amounts of euhedral zircon anatase apatite and massive silica with vesicular structure were also examined these constitute strong evidence for its felsic volcanic ash origin

mineralogy and geochemistry of coal from the liupanshui mining district guizhou south china abstract this study focuses on the geochemistry and mineralogy of 23 coal seams from the shuicheng and luizhi coal fields from the late permian liupanshui coal mining district in the west of guizhou province in southern china coal rank ranges widely from high volatile bituminous to low volatile bituminous and anthracite major mineral phases present in the liupanshui coal are kaolinite quartz pyrite and calcite traces of other primary minerals are marcasite gypsum and dolomite the shuicheng coal usually has higher kaolinite and quartz contents than the luizhi coal marcasite occurs indiscriminately in the different coal seams without a clear distribution pattern the presence of other minerals such as rutile anatase tourmaline zircon and phosphates was also noted the total sulphur content of liupanshui coals is higher in the marine influenced coal seams up to 7 5 dry and lower in the nonmarine influenced coals as low as 0 3 in the luizhi coal field the coal is characterised by a high sulphur and iron content whereas in the shuicheng coal field contents varied from low to high depending on the coal seams an inverse geochemical distribution was detected for the mean contents of ca mn ge with lower contents in the luizhi coal field the liupanshui coals are characterised by relatively high contents of mn v cu li zr nb hf ta tl th and u when comparing with the usual concentration ranges in bituminous coals trace elements in coals from liupanshui showed narrow variations in their concentrations among coal seams and coal three major trace element affinities aluminium silicates sulphides and carbonates accounted for the occurrence and distribution of most of the elements studied were determined

geochemistry of trace elements in chinese coals a review of abundances genetic types impacts on human health and industrial utilization abstract china will continue to be one of the largest coal producers and users in the world the high volume of coal use in china has focused attention on the amounts of toxic trace elements released from coal combustions and also the valuable trace elements extracted or potentially utilized from coal ash compared to world coals chinese coals have normal background values for most trace elements with the exception of higher li 31 8 g g zr 89 5 g g nb 9 44 g g ta 0 62 g g hf 3 71 g g th 5 84 g g and rare earth elements la lu y 136 g g this is not only due to the higher ash yields of chinese coals but also to alkali volcanic ashes found in some southwestern coals the background values of toxic elements of hg 0 163 g g as 3 79 g g and f 130 g g in chinese coals are comparable to coals from most other countries the genetic types for trace element enrichment of chinese coals include source rock controlled marine environment controlled hydrothermal fluid controlled including magmatic low temperature hydrothermal fluid and submarine exhalation controlled subtypes groundwater controlled and volcanic ash controlled the background values of trace elements were dominated by sediment source regions low temperature hydrothermal fluid was one of the major factors for the local enrichment of trace elements in southwestern china serious human health problems caused by indoor combustion of coal in china include endemic fluorosis arsenosis selenosis and lung cancer endemic fluorosis mainly occurring in western guizhou was mostly attributed to the high fluorine in clay that was used as a briquette binder for fine coals in addition to a small quantity of fluorine from coal fluorine in the coal from endemic fluorosis areas of western guizhou is within the usual range found in china and the world endemic arsenosis in southwestern guizhou is attributed to indoor combustion of high as coal endemic selenosis in enshi of hubei was due to high se in carbonaceous siliceous rocks and carbonaceous shales fine particles of quartz released into air during coal combustion are hypothesized as a possible cause for the lung cancer epidemic in xuanwei yunnan china valuable elements including ge ga u ree rare earth element nb zr and re are concentrated to levels comparable to conventional economic deposits in several coals or coal bearing strata in china the ge deposits at lincang yunnan province and wulantuga inner mongolia have been exploited and industrially utilized the enrichment of ge in the two deposits was caused by hydrothermal fluids associated with adjacent granitoids the ga al ore deposit in the jungar coalfield inner mongolia was derived from the neighboring weathered and oxidized bauxite of the benxi formation pennsylvanian the nb ta zr hf ree ga deposits in the late permian coal bearing strata of eastern yunnan and chongqing of southwestern china were attributed to ashes of the alkali volcanic eruptions

kinematic analysis of rock flow and deformation temperature of the sirjan thrust sheet zagros orogen iran microstructural finite strain and vorticity analyses of quartz rich mylonites were used in order to investigate kinematics of rock flow and deformation temperature in the sirjan thrust sheet exposed in a structural window within the sanandaj sirjan high pressure low temperature hp lt metamorphic belt that forms part of the hinterland of the zagros orogenic belt of iran a dominant top to the sw sense of shear in the study area is indicated by several shear sense indicators such as asymmetric boudins rotated porphyroclasts mica fish and s c fabrics quantitative analyses reveal approximately plane strain deformation conditions with r xz values ranging from 2 5 to 4 3 and increasing towards the sirjan thrust opening angles of quartz c axis fabrics and recrystallization regimes suggest deformation temperatures vary from 430 to 625 50 c in the hanging wall rocks oblique grain shape and quartz c axis fabrics were used to estimate the degree of non coaxiality during deformation the obtained vorticity profile indicates a down section increase in kinematic vorticity number w m from 0 6 to 0 89 this range of vorticity numbers confirms contributions of both simple 41 68 and pure shear 32 59 deformation components the structural characteristics of the study area ultimately were controlled by oblique motion of the afro arabian plate relative to the iranian plate

rare earth element and yttrium content of coal in the banko coalfield south sumatra basin indonesia contributions from tonstein layers abstract the south sumatra basin is one of the most prolific coal basins in indonesia most of the coal from this area is used as thermal coal seredin and dai 2012 explained the importance and significance of coal deposits as potential sources for rare earth elements and yttrium rey the concentrations of these elements in coal are similar to their abundances in conventional rey deposits production of the rey in coal deposit is mainly from the coal s fly bottom ash examination of coal with high rey concentrations is becoming a very important issue the study area is located in the banko coalfield sumatra indonesia this area is one of the best candidates for studying rey in coal because there are tuffaceous mudstone layers tonsteins reported by previous researchers that may have enriched the coal in rey for this study coal and non coal beds from the same stratigraphic interval were sampled and analyzed using thin and polished section x ray diffraction xrd inductively coupled plasma atomic emission spectroscopy icp aes and inductively coupled plasma mass spectrometry icp ms special attention was given to coals near the tonstein layers based on the data collected it was concluded that all the tonsteins studied are of volcanic origin and are silicic and alkali tonsteins the elements al and si are higher in coal samples collected just beneath the tonstein layers and the highest rey concentration found was in a sample beneath a silicic tonstein layer these data suggest that there is an opportunity to extract rey from coal s fly bottom ash because the rey content of the ash is as much as 10 times higher than the rey content of the coal feed to power plants

geochemistry of rare earth elements in a marine influenced coal and its organic solvent extracts from the antaibao mining district shanxi china twenty six samples including roof bottom and coal plies of a marine influenced coal bed were collected from the antaibao mining district shanxi china the rare earth elements rees were determined in solids and organic solvent extracts the distribution pattern showed three distinct patterns shale like lree rich and hree rich this is attributed to the variable microenvironment of peat forming swamp the degree of marine influences and different ree sources rees in the coal are mainly controlled by detrital minerals but also affected by seawater the chondrite normalized ree patterns of the organic solvent extracts are distinctly different from those of corresponding original coal samples which show a negative eu anomaly a depletion of middle rees and an enrichment of hrees the lrees in coal extracts are likely adsorbed by hydrogen containing functional groups and hrees are likely bonded to carbon atoms

mineralogy of a rare earth element rich manchester coal lithotype clay county kentucky abstract many eastern kentucky coals have high ree contents with lithotypes of the pennsylvanian age manchester coal rivaling some of the richest concentrations in the fire clay coal arguably the premier resource in terms of concentration and aerial extent a 2000 ppm ree y rey ash basis 2 13 ash manchester coal lithotype analyzed first by scanning electron microscopy was selected for detailed transmission electron microscopy energy dispersive x ray spectroscopy fast fourier transform selected area electron diffraction investigation tem eds fft saed the mineral grains extracted from the coal seemingly fragments of one or more 2 to 3 m spherical nodules proved to have a phosphate rhabdophane rim with a light ree la through sm and gd association the core of the nodule and the region surrounding the nodule is al si rich but the mineralogy could not be determined the nodule may be a mineralized coprolite the product of the microfauna inhabiting the peat

coal petrography mineralogy elemental compositions and palaeoenvironmental interpretation of late carboniferous coal seams in three wells from the kozlu coalfield zonguldak basin nw turkey abstract a number of coal seams of late carboniferous age in the coal bearing karadon kozlu and alacaagzi formations have been mined in several deep underground mines in the zonguldak basin nw turkey for this study a total of 154 coal core samples were collected from three research wells that were drilled in the tectonically complex settings of the kozlu coalfield all the coal samples were studied by means of coal petrography mineralogy and geochemistry special attention was given to the compositions and origins of fracture cleat filling minerals that were identified by sem edx on polished blocks the coal seams investigated are of bituminous rank they are characterized by low total sulphur contents 1 0 on dry basis and high gross calorific values 22 5 40 2 mj kg on dry ash free basis whereas ash yields and volatile matter contents are variable x ray powder diffraction data indicate that the mineralogical compositions of the studied coal seams are rather similar and clay minerals along with quartz and carbonate minerals were identified in almost all seams the statistical evaluations and sem data show that some elements such as mg ti zr nb and th are generally affiliated with silicate minerals whereas elements like cu zn mo and pb are mainly associated with sulphide minerals the silicate minerals are generally detrital and the majority of carbonate minerals are of epigenetic origin the epigenetic carbonate and sulphide minerals suggest that circulated solutions within coal seams were mainly derived from ca2 rich solutions leached from overlying formations such as cretaceous aged zonguldak formations and from hydrothermal solutions that likely were derived from andesitic dykes within the basin the regional tectonic activities during coalification seem to have deformed coal bearing formations and therefore intra basinal solutions could have penetrated into the studied coal seams the epigenetic mineralisation also resulted in elemental enrichments and elevated ash yields total sulphur and volatile matter contents in some coal seams thus deformation during coalification controlled some coal quality parameters in the studied wells the coal facies diagrams suggest that palaeomires mostly accumulated under limno telmatic conditions whereas a telmatic environment was more common in palaeomires of the kozlu formation coal petrography suggests that peat forming vegetation and water tables in palaeomires were changeable during the late carboniferous

coal facies studies in the eastern united states coals in the eastern united states east of the mississippi river have been the subject of a number of coal facies studies going back to the 19th century such studies would not necessarily fall within a strict modern classification of coal facies studies but if a study encompassed some aspects of paleobotany palynology petrology geochemistry or sedimentology we assumed that some data and interpretations may be of use in evaluations of the facies references are presented as a guide for further research with annotation in the tables

differentiation of volcanic ash fall and water borne detrital layers in the eocene senakin coal bed tanjung formation indonesia abstract the sangsang deposit of the eocene senakin coal bed tanjung formation southeastern kalimantan indonesia contains 11 layers which are thin 70 these layers are characterized by their pelitic macroscopic texture examination of eight of the layers by scanning electron microscopy energy dispersive x ray and x ray diffraction analyses show that they are composed primarily of fairly well crystallized kaolinite much of which is vermicular accessory minerals include abundant ti oxide rare earth element rich ca and a1 phosphates quartz that luminescences in the blue color range and euhedral to subhedral pyroxene hornblende zircon and sanidine although this mineral suite is suggestive of volcanic ash fall material only the four pelitic layers in the middle of the bed are thought to be solely derived from volcanic ash falls on the basis of diagnostic minerals replaced glass shards and lithostratigraphic relationships observed in core and outcrop the three uppermost pelitic layers contain octahedral chromites some quartz grains that luminesce in teh orange color range and some quartz grains that contain two phase fluid inclusions these layers are interpreted to be derived from a combination of volcanic ash fall material and hydrologic transport of volcaniclastic sediment in contrast the lowermost pelitic layer which contains large rounded femg rich chromites is thought to have been dominantly deposited by water the source of the volcanic ash fall material may have been middle tertiary volcanism related to plate tectonic activity between kalimantan and sulawesi the volcanic ash was deposited in sufficient amounts to be preserved as layers within the coal only in the northern portions of the senakin region the southern coal beds in the region do not contain pelitic layers

mineral matter and trace elements in coals of the gunnedah basin new south wales australia abstract the concentrations of major and trace inorganic elements in a succession of permian coals from the gunnedah basin new south wales have been determined by x ray fluorescence techniques applied to both whole coal and high temperature ash samples the results have been evaluated in the light of quantitative data on the minerals in the same coals determined from x ray diffraction study of whole coal samples using a rietveld based interpretation program siroquant to determine relationships of the trace elements in the coals to the mineral species present comparison of the chemical composition of the coal ash interpreted from the quantitative mineralogical study to the actual ash composition determined by xrf analysis shows a high degree of consistency confirming the validity of the xrd interpretations for the gunnedah basin materials quartz illite and other minerals of detrital origin dominate the coals in the upper part of the sequence whereas authigenic kaolinite is abundant in coals from the lower part of the permian succession these minerals are all reduced in abundance however and pyrite is a dominant constituent in coals formed under marine influence at several stratigraphic levels calcite and dolomite occur as cleat and fracture infillings mostly in seams near the top and bottom of the sequence the potassium bearing minerals in the detrital fraction are associated with significant concentrations of rubidium and the authigenic kaolinite with relatively high proportions of titanium zirconium is also abundant with associated p and hf in the gunnedah basin coal seams relationships exhibited by ti zr nd and y are consistent with derivation of the original sediment admixed with the seams from an acid volcanic source pyrite in the coals is associated with high concentrations of arsenic and minor proportions of thallium no other element commonly associated with sulphides in coals however appears to occur in significant proportions with the pyrite in the sample suite small concentrations of cl present in the coal are inversely related to the pyrite content and appear to represent ion exchange components associated with the organic matter strontium and barium are strongly associated with the cleat filling carbonate minerals ge and ga appear to be related to each other and to the coal s organic matter cr and v are also related to each other as are ce la nd and pr but none of these show any relationship to the organic matter or a particular mineral component

trace element geochemistry of altered volcanic ash layers tonsteins in late permian coal bearing formations of eastern yunnan and western guizhou provinces china trace element compositions were determined by instrumental neutron activation analysis inaa in 30 samples of synsedimentary volcanic ash derived tonsteins and detrital claystones from coal seams within the late permian coal bearing formation of eastern yunnan and western guizhou provinces china the characteristics of trace element geochemistry in the tonsteins can be distinguished from those of detrital claystones because of the former s unique volcanic ash origin the detrital claystones are characterized by their relatively high content of v ti sc cr co and ni relatively low content of th and u th u ratio and small negative eu anomaly eu eu 0 63 0 93 overall these trace element characteristics are consistent with a mafic source similar to the composition of basalt rocks in the erosional region on the western edge of the study area in contrast the tonsteins are low in v ti sc cr co and ni contents and have a high th u ratio with a distinct negative eu anomaly eu eu normally in the range of 0 2 0 4 consistent with a silicic magmatic source within the group of tonsteins those from the lower section p2 1 of the coal bearing formation are relatively high in ti zr hf nb ta and rare earth elements ree as compared to those from the middle and upper sections p2 2 3 in trace element discrimination diagrams scatter plots of hf ta ti ta ti v hf sc lu hf and lu th tonsteins from the p2 1 horizon always fall in isolated distribution areas separate from the tonsteins of the p2 2 3 horizon these results suggest that the source materials of tonsteins from the two separate horizons were probably derived from volcanic ash falls of two distinctly different natures based on a comparison of the concentrations and assemblages of trace elements between various magmatic rocks the source materials of tonsteins from p2 1 horizon were mostly composed of calc alkalic silica poor volcanic ash similar to rhyodacitic magma whereas those from p2 2 3 were apparently more siliceous and k rich rhyolitic magma thus tonsteins from the two different horizons are characterized by unique geochemical properties which remain constant over a wide lateral extent integration of trace elemental compositions with mineralogical and textural observations makes possible the establishment of tonstein stratigraphy thus facilitating more precise and reliable coal seam correlations

a preliminary study of mineralogy and geochemistry of four coal samples from northern iran abstract this study is related to four jurassic age bituminous coal 0 69 1 02 ro samples collected from coal mines from the west central and east of central alborz in northern iran geological settings played key roles in determining the geochemistry and mineralogy of coals from the central alborz region of northern iran the mineralogy of coals from the eastern part of the region is dominated by kaolinite halloysite and carbonates such as calcite dolomite ankerite and siderite the coals were deposited in a lacustrine environment in the western part of the region where the depositional setting was also lacustrine with volcanic input and tonstein deposition glass shards present the coal primarily contains kaolinite 68 and fluorapatite 26 in contrast coal from the central part of the region which was deposited in a terrestrial environment and on eroded limestone and dolomite rocks is dominated by dolomite 98 with little input by kaolinite these coals have low sulphur 0 35 0 70 wt which is mostly in the organic form 0 34 0 69 wt pyritic sulphur is detected only in one coal and in small quantities the boron contents of these coals range from 9 to 33 mg kg indicating that deposition occurred in a fresh water environment coal with higher concentrations of ba sr and p contain fluorapatite and goyazite gorceixite series baal 3 po 4 2 oh 5 h 2 o minerals which indicates volcanoclastic input compared to world coal averages these coals exhibit low concentrations of elements of environmental concern such as as 1 3 5 9 mg kg cd

geochemistry of trace elements in the kesan coal and its effect on the physicochemical features of ground and surface waters in the coal fields edirne thrace region turkey abstract in this study concentration and origin of trace elements of the kesan coals in edirne thrace basin have been investigated in order to determine possible environmental impacts on water pollution the coal ground and surface waters and clay samples were taken from the coal mining area the concentration of trace elements in 14 coal ashes 15 water samples and seven clays was determined by inductively coupled plasma mass spectrometry additionally 11 of these coal samples were studied by proximate and seven coal samples were also studied by x ray diffraction analyses the mineralogical composition of the studied coal samples is made up mainly of quartz clay minerals feldspar group minerals pyrite and amorphous matter the kesan coal ash samples have higher average concentrations of cr 180 ppm ni 192 ppm rb 91 ppm and sr 1701 ppm average values of other trace elements are lower than the world average of brown coal ashes the sulfur content of the kesan coals ranges from 0 4 to 3 90 2 02 on average the ph values of the waters vary between 6 55 and 8 36 in coal fields 7 21 and 7 54 in springs the f cl no 3 so 4 ca mg na and k values of the waters vary between 0 11 and 0 25 mg l 33 49 and 52 90 mg l 0 05 and 59 27 mg l 85 and 2829 mg l 66 and 349 mg l 64 and 222 mg l 41 and 1187 mg l 2 and 13 mg l respectively in coal fields some elements are anomalous in concentrations in some water samples e g cr up to 49 6 ppb mn up to 1185 ppb fe up to 10 352 ppb ni up to 55 8 ppb as up to 9 7 ppb ppb it has been interpreted that the lower trace element concentrations in the water samples may be due to clay intercalated with coal the clays are smectite type and they are enriched in cr co ni as sr and th e g up to 394 ppm cr up to 305 ppm ni and up to 35 5 ppm as

elements and phosphorus minerals in the middle jurassic inertinite rich coals of the muli coalfield on the tibetan plateau abstract the content modes of occurrence and origin of elements and phosphorus minerals in the jurassic coals of the muli coalfield on the tibetan plateau were investigated using optical microscopy field emission scanning electron microscopy in conjunction with energy dispersive x ray spectrometry x ray powder diffraction x ray fluorescence spectrometry and inductively coupled plasma mass spectrometry the muli coals l1 and l2 coals are of high volatile a bituminous to medium volatile bituminous rank characterized by low sulfur contents and are generally dominated by the inertinite group macerals predominantly semifusinite and fusinite the l1 coal contains abundant apatite 7 9 on average on an organic matter free basis and alumino phosphate minerals of goyazite gorceixite crandallite group 4 9 on average and accordingly the concentrations of elements f 253 g g on average p 2349 g g sr 526 g g and ba 790 g g are elevated as compared with common world hard coals the deposition of phosphorous bearing minerals in the muli coals was not derived from volcanic input penetration of ca and al rich solutions release of phosphorus from organic matter during plant decay and an appropriate sedimentary environment such as low ph low water table for peat and oxidizing conditions were critical factors in deposition of the phosphorus minerals

notes on the marginal enrichment of germanium in coal beds germanium distribution in coal has long been a topic of interest the enrichment of ge near margins of coals including the margins of partings within the coal has been noted in many coals from numerous coalfields throughout the world in this paper a summary of literature on ge geochemistry on the upper and lower margins of coal seams with special emphasis on the literature of russia and the former soviet union and japan is presented

lanthanide yttrium and zirconium anomalies in the fire clay coal bed eastern kentucky abstract the fire clay coal bed in the central appalachian basin region contains a laterally persistent tonstein that is found in the coal throughout most of its areal extent the tonstein contains an array of minerals including sanidine quartz anatase and euhedral zircon that constitutes strong evidence for a volcanic origin of the parting for this study five samples of the tonstein and four sets of coal samples underlying the tonstein were collected from five sites in eastern kentucky inductively coupled plasma mass spectroscopy icp ms analysis of the tonstein and underlying coal collected from four sites in eastern kentucky show that although zr concentrations are high in the tonstein 570 1820 ppm on a coal ash basis cab they are highest in the coal directly underlying the tonstein 2870 4540 ppm cab a similar enrichment pattern is observed in the concentration of y plus the sum of the rare earth elements y ree total y ree concentrations in the five tonstein samples range from 511 to 565 ppm cab however y ree contents are highest in the coals directly underlying the tonsteins values range from 1965 to 4198 ppm cab scanning electron microscopy of samples from coal which directly underlies two of the tonstein samples show that ree rich phosphate tentatively identified as monazite commonly infills cracks in clays and cells in clarain and vitrain zircon is rare and commonly subhedral on the basis of coal chemistry and grain morphology we suggest that volcanic components in the tonstein were leached by ground water the leachate rich in y and ree precipitated as authigenic mineral phases in the underlying coal

rare earth elements and yttrium in lithotypes of bulgarian coals abstract rare earth element and yttrium abundances in vitrain xylain liptain fusain and whole coal samples from bulgarian coal deposits have been studied vitrain xylain and liptain are depleted while fusain is enriched in ree and y as compared to the whole coal samples from which they were selected chondrite normalized patterns show relative enrichment of light lree against heavy hree rare earth elements negative eu anomaly and positive lu anomaly the shale normalized patterns of the lithotypes reveal an increase from lree to hree while those of the whole coal samples and mineral interlayers are less fractionated the petrographic composition of the coals is of secondary importance for the concentration of the ree and y the main factors are the source area and the input of dissolved ree and y into the coal depositional sites

a review of anomalous rare earth elements and yttrium in coal abstract coal deposits have attracted much attention in recent years as promising alternative raw sources for rare earth elements and yttrium rey not only because the rey concentrations in many coals or coal ashes are equal to or higher than those found in conventional types of rey ores but also because of the world wide demand for rey in recent years has been greater than supply in addition to anomalies of enrichment or depletion of light medium and heavy rey in coal deposits normalized to upper continental crust post archean australian shale or north american shale composite anomalies of redox sensitive ce and eu and in some cases of non redox sensitive la gd and y could be used as geochemical indicators of the sediment source region sedimentary environment tectonic evolution and post depositional history of coal deposits factors controlling rey anomalies in coal deposits include the geochemistry of terrigenous source rocks ingress of hydrothermal fluids influence of marine environments percolating natural waters volcanic ashes and sedimentary environments of peat formation additionally the smoothness of a normalized rey distribution pattern provides a simple but reliable basis for testing the quality of rey chemical analyses for coal and other sedimentary rocks

occurrence of analcime in the middle jurassic coal from the dongsheng coalfield northeastern ordos basin china abstract this paper describes the occurrence of significant authigenic analcime naalsi2o6 h2o in the middle jurassic coal from the northeastern ordos basin and discusses its origin twelve coal samples from borehole zk31 19 in the dongsheng coalfield were collected and analyzed the coals are characterized by a low medium ash yield high volatile matter and low sulfur contents the major element oxides in the studied coals are mostly at similar or much lower concentrations compared to the averages for chinese coals similarly most trace elements are depleted or in concentrations close to the respective averages for world low rank coals based on seredin dai s classification the rey rare earth elements and y in the coal mainly display n and h type distribution patterns with no ce and eu anomalies coal sample zk31 19 12 from the lower zhiluo formation contains analcime up to 23 wt with a high na2o concentration of 1 23 both on a whole coal basis the analcime occurs as lath as subhedral granular crystals in fissures or pores and as anhedral crystals in the organic matrix furthermore significant analcime has also been observed by sem in coal from the upper yan an formation sample zk31 19 10 which mainly occurrs as anhedral crystals no evidence of analcime forming from precursors of volcaniclastic material alkali zeolites or other silicates was detected therefore it is deduced that the analcime in the studied coals formed by authigenic precipitation the na2o content in the studied coal seams displays a vertical variation different from that of the ash yield ad and those of the detrital dominated elements such as sio2 al2o3 tio2 zr nb and th indicating a different origin of na compared with other detrital materials of terrigenous origin combined with the evidence of the obvious na peak in authigenic amorphous material and gypsum mineral by sem it can be inferred that the source of na may derive from the fluids the paleoclimatic change from subtropical warm and humid to semi arid and arid hot during the deposition period of the yan an to the zhiluo formation may provide favorable conditions for analcime authigenesis leading to its abundant precipitation in the lower zhiluo formation and its limited occurrence in the upper yan an formation such paleoclimatic change is also significant for the u mineralization in the lower zhiluo formation

the effects of volcanic ash on the maceral and chemical composition of the c coal bed emery coal field utah abstract volcanic ash which fell in the peat swamp that formed the upper cretaceous c coal bed ferron sandstone member of the mancos shale utah produced semi impermeable layers that caused the ponding of surface waters coal samples from directly above tonsteins altered volcanic ash partings are enriched in desmocollinite telinite and detrocollinite as a result of poorly drained swamp conditions coal samples from directly below tonsteins are enriched in semifusinite inertodetrinite and fusinite as a result of well drained conditions leaching of the volcanic ash or the incorporation of volcanic ash in peat provided a source for many elements including zr nb th and ce that are enriched in coal samples taken from directly above and below tonsteins

late cretaceous coal overlying karstic bauxite deposits in the parnassus ghiona unit central greece coal characteristics and depositional environment abstract the pera lakkos coal located on top of bauxite deposits in the ghiona mining district central greece is the only known mesozoic late cretaceous coal in the country it was derived from herbaceous plants and algae growing in mildly brackish mires that formed behind a barrier system during a regression of the sea on a karstified limestone partly filled in with bauxitic detritus petrological mineralogical and geochemical data point to the predominance of reducing conditions and intense organic matter degradation in the palaeomires o c vs h c and oi vs hi plots based on elemental analysis and rock eval data characterize kerogen types i ii this reflects the relatively high liptinite content of the coal besides kerogen composition o c vs h c plot for the pera lakkos coals is in accordance with a catagenesis stage of maturation in contrast with vitrinite reflectance and t max from rock eval pyrolysis which indicate the onset of oil window maturation stage suppression of vitrinite reflectance should be considered and the high liptinite content corroborates this hypothesis despite some favourable aspects for petroleum generation presented by the pera lakkos coal its maximum thickness up to 50 cm points to a restricted potential for petroleum generation coal oxidation took place either during the late stage of peat formation due to wave action accompanying the subsequent marine transgression or epigenetically after the emergence of the whole sequence due to percolation of drainage waters both options are also supported by the ree shale normalized profiles which demonstrate an upwards depletion in the coal layer oxidation also affected pyrite included in the coal this led to the formation of acidic sulfate rich solutions which percolated downwards resulting in bleaching of the upper part of the underlying bauxite

petrological geochemical and mineralogical compositions of the low ge coals from the shengli coalfield china a comparative study with ge rich coals and a formation model for coal hosted ge ore deposit abstract to better understand the formation mechanism of coal hosted ge ore deposits this paper reports on the petrological mineralogical and geochemical compositions of the low ge coals in the shengli coalfield inner mongolia china using optical microscopy field emission scanning electron microscopy x ray fluorescence x ray diffraction and inductively coupled plasma mass spectrometry the samples in the present study closely neighbor the previously reported wulantuga coal hosted ge ore deposit both no 6 coal in comparison with the wulantuga ge rich coals the low ge coals of the shengli field display higher moisture 27 59 on average and lower pyritic sulfur contents 0 53 both the low ge and ge rich coals are generally high in inertinite and have varying but relatively low huminite contents preservation of fecal pellets as macrinite is notable in both the low ge and ge rich coals and the position of the fecal pellets appears to be within tunnels or chambers within the wood quartz kaolinite pyrite and gypsum are the major crystalline phases identified in most of the ge rich and low ge coals but the low ge coals contain significantly less pyrite and are more abundant in non mineral ca and mg ca oxalate of authigenic origin is observed generally occurring as cell fillings in the low ge coals otherwise mineral free organic matter in the low ge coals would be expected to have an inherent ash yield of around 6 derived from the inorganic elements mainly non mineral ca and mg that occur either in the organic matter or as dissolved ions in the pore water and form the sulfate species in low temperature oxygen plasma ash residues the highly elevated trace elements including be ge as sb w hg and tl that occur in the ge rich coals of the wulantuga deposit are significantly depleted in the low ge coals lateral migration of ge w and as hg sb tl rich solutions through the original peat swamp for the wulantuga ge ore deposit has led to significant enrichment of ge on the margin of the coal basin but decreasing ge concentrations toward to the inner part of the basin such a migration direction is different to those in the previously reported for the hydrothermal solutions in the lincang yunnan of china and spetzugli russian far east ge ore deposits where the solutions migrated vertically from granite to peat along faults and led to a dome shaped ge distribution in the relevant coal seam

factors affecting the geochemistry of a thick subbituminous coal bed in the powder river basin volcanic detrital and peat forming processes abstract the inorganic geochemistry and mineralogy of three cores from the anderson dietz 1 coal bed a 15 2 m thick subbituminous coal bed in the tongue river member paleocene of the fort union formation were examined 1 to determine if the cores could be correlated by geochemical composition alone over a total distance of 2 km and 2 to identify the major factors that influenced the geochemistry of the coal bed chemical data 46 elements on a coal ash basis for 81 coal samples and 4 carbonaceous rock samples with most samples representing a 0 6 m thick 2 ft interval of core were grouped into compositional clusters by means of cluster analysis seven major clusters were produced two of these clusters can be used to correlate the coal bed throughout the study area data from scanning electron and optical microscope analyses indicate that several factors influenced the geochemistry of the anderson dietz 1 coal bed the majority of mineral grains in the coal bed are interpreted to be detrital water borne evidence includes the presence of rounded to subrounded quartz grains having two phase aqueous fluid inclusions characteristic of hydrothermal or low to moderate grade metamorphic quartz these quartz grains are found throughout the coal bed but are most abundant in samples from the midpart of the bed which was influenced by detrital input associated with the deposition of the clastic rocks that form the split between the anderson and dietz 1 coal beds 900 m to the east of the study area in addition to the detrital minerals mentioned above volcanic ash that was fluvially transported to the sites of peat deposition or possibly deposited as air fall volcanic ash also affected the geochemistry of the coal bed for example crandallite a mineral reported to form as an alteration product of volcanic ash is found in seven samples from the coal bed the presence of quartz grains containing silicate melt inclusions in eight samples from the coal bed provides further support for a volcanic ash component other factors that probably affected the geochemistry of the coal bed include 1 detrital input associated with the deposition of the roof rocks of the coal bed 2 peat forming processes and plant material and 3 epigenetic ground water flow

concentration and distribution of elements in late permian coals from western guizhou province china abstract with the aim of better understanding geochemistry of coal 71 late permian whole seam coal channel samples from western guizhou province southwest china were studied and 57 elements in them were determined the contents of al ca co cr cu fe ga hf k li mn mo nb ni sn ta ti th u v zr and rees in the late permian coals from western guizhou province are higher than the arithmetic means for the corresponding elements in the us coals whereas as ba br f hg p se and tl are lower compared to common chinese coals the contents of co cr cu ga hf li mn mo ni sc sn ti u v zn and zr in western guizhou coals are higher and as f hg rb sb tl and w are lower five groups of elements may be classified according to their mode of occurrence in coal the first two group a tm yb lu y er ho dy tb ce la nd pr gd sm and group b as sr k rb ba f ash si sn ga hf al ta zr be th na have high positive correlation coefficients with ash yield and they show mainly inorganic affinity some elements from group b such as ba be ga hf and th are also characterized by significant aluminosilicate affinity in addition arsenic also exhibits high sulfide affinity r s fe 0 5 the elements which have negative or lower positive correlation coefficients with ash yield with exceptions of bi cs nb mn se and ti are grouped in other four associations group c cr v mo u cd tl group d hg li sc ti eu nb cs w group e bi sb and group f co ni cu pb zn mg se ca mn s fe the correlation coefficients of some elements including co cr cu fe hg li mo ni p s sc u v and zn with ash yield are below the statistically significant value only cr and cu are negatively correlated to ash yield 0 07 and 0 01 respectively showing intermediate organic and inorganic affinity manganese and fe are characterized by carbonate affinity probably due to high content of epigenetic veined ankerite in some coals phosphorus has low correlation coefficients with any other elements and is not included in these six associations there are five possible genetic types of enrichment of elements in coal from western guizhou province source rock volcanic ash low temperature hydrothermal fluid groundwater and magmatic hydrothermal inputs