petrologic and geochemical characteristics of seam 9 3 and seam 2 xingtai coalfield northern china abstract six samples of carboniferous mississippian pennsylvanian coal seam 9 3 and 11 samples of permian coal seam 2 from the xingtai coalfield were studied by petrological and organic geochemical methods both seams show different petrological and geochemical compositions in seam 9 3 of the carboniferous age the predominant maceral is vitrinite 83 whereas in seam 2 of permian age inertinite predominates 45 barkinite was found with an average content 1 only in seam 2 sixty four different aromatic compounds were identified by gas chromatography gc mass spectrometry ms analysis of solvent extracts extr of both seams abundant polyaromatic sulfur hydrocarbons pash were determined in coal samples from seam 9 3 while they are very low in samples from seam 2 1 2 5 trimethylnaphthalene and 1 2 5 6 tetramethylnaphthalene contents are much higher in seam 2 while 2 methylfluorene contents are higher in seam 9 3 cadalene was found in seam 2 with a high content of 94 mg kg coal but was not detected in samples from seam 9 3 this might indicate a different floral contribution to the sedimentary organic matter all petrologic and geochemical results indicate that seam 2 formed in a more oxidized environment compared with seam 9 3

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

ragged edge of the herrin no 11 coal western kentucky abstract the herrin no 11 coal in western kentucky is normally a bright banded high vitrinite high sulfur coal three sites have been found where the coal deviates from the expected appearance in union county a site known only from a literature description the upper two thirds of the coal was described as a cannel in ohio county a thin truncated section of the herrin coal has a greater abundance of liptinite and inertinite rich microlithotypes towards the top of the seam the various microlithotypes were frequently found in brecciated assemblages in hopkins county the herrin coal was found to be largely a coarse breccia of oxidized macerals cemented by calcite a marine limestone was present as a parting within the coal each occurrence represents the edge of the coal the sites varied in the energy of the environment and perhaps also in proximity to marine waters

distribution isotopic variation and origin of sulfur in coals in the wuda coalfield inner mongolia china abstract this paper describes coal petrographic characteristics sulfur abundance distribution and isotopic signature in coals in the wuda coalfield inner mongolia northern china petrographic studies suggest that depositional environment influences petrographic composition the no 9 and no 10 coal seams which are thought to have formed on a tidal delta plain have high collodetrinite contents up to 66 1 indicating enhanced gelification and bacteria activity during coal accumulation and also have the highest sulfur content 3 46 and 3 42 both organic and pyritic sulfur isotope values 12 3 to 5 8 and 18 7 to 1 1 respectively are variable and generally tend to be more negative in high sulfur coals than those in low sulfur coals in the wuda coalfield the negative sulfur isotope values indicate that a large portion of sulfur in the high sulfur coals has a bacterial origin sulfur isotopic compositions and variations within the section were used to propose a model to explain the origin of sulfur in these coals the presence of pyritized rod like bacteria cyanophyte s gelatinous sheaths and degraded algae organic matter suggests that bacteria and perhaps algae may play an important role in the formation of these high sulfur coals

distribution of selected trace elements in density fractionated waterberg coals from south africa abstract the waterberg coalfield located in the limpopo province north western area of south africa contains a significant proportion of the south african coal resource this permian coalfield typically contains high vitrinite high ash coals in the kungurian grootegeluk formation and high inertinite low ash coals in the artinskian vryheid formation four run of mine coals and density fractioned samples were analysed to determine their trace element content the concentrations of most trace elements in the run of mine coals exceed the global averages and certain global ranges and generally exceed values reported for other south african coalfields specifically hg concentrations are high to very high in all the coals up to 2 43 ppm in a sample from the vryheid formation cd and se concentrations are comparable to or lower than global averages and as is very low in the vryheid formation 1 57 ppm a sample from the grootegeluk formation is enriched in siderophile elements and a sample from the vryheid formation is depleted in chalcophile elements studies of the density fractionated samples indicate that cd exhibits an organic affinity in the grootegeluk formation samples and possibly a pyritic or sulphide affinity in the vryheid formation sample selenium has a greater affinity for the middle clay rich density fractions in all samples arsenic reports to the mineral rich sink fractions specifically the fractions enriched in pyrite mercury reports to both the float and sink fractions indicating an organic and inorganic affinity in these coals although there is more enrichment in the sink fractions in the grootegeluk formation samples and a definite organic correlation in the vryheid formation sample

dynamics of magma mixing and degassing recorded in plagioclase at stromboli aeolian archipelago italy crystal rich materials scoriae and lava flows emitted during the 1985 2000 activity of stromboli were taken into consideration for systematic study of bulk rock matrix glass chemistry and in particular for the study of chemical and textural zoning of plagioclase the most abundant mineral phase over the considered time period bulk rock composition remained fairly constant in both major sio2 49 2 50 9 wt and k2o 1 96 2 18 wt and trace elements the quite constant chemistry of matrix glasses also indicates that the degree of crystallization of magma was maintained at around 50 vol plagioclase ranges in composition between an62 and an88 and is characterized by alternating 10 100 m thick bytownitic and labradoritic concentric layers although the dominant and representative plagioclase of scoriae is an68 the labradoritic layers an62 70 show small scale 1 5 m oscillatory zoning are free of inclusions and appear to record episodes of slow crystal growth in equilibrium with a degassed liquid having the composition of the matrix glass in contrast the bytownitic layers an70 an88 are patchy zoned show sieve structure with abundant micrometric glass inclusions and voids and are attributed to rapid crystal growth

concentration and mode of occurrence of trace elements in marine oil shale from the bilong co area northern tibet china abstract the bilong co oil shale zone is located in the south qiangtang depression this zone together with the shengli river changshe mountain oil shale zone in the north qiangtang depression northern tibet plateau represents a potentially large marine oil shale resource in china with the aim of better understanding geochemistry of marine oil shale 18 samples from the bilong co area are studied and 56 elements in them are determined the contents of mo se cd cs as bi u rb pb th li sr and zn are enriched from 1 3 to 35 0 times as compared with the average concentration in the crust clarke values whereas the other elements are slightly higher lower than the respective clarke values compared to common australian oil shales the contents of ce co cs f ga hf nb nd pb pr rb sc sn th and zr in the bilong co oil shale samples exhibit relatively high levels whereas as br cd cr cu dy er eu ho lu mo ni se tb tm u v y yb and zn are relatively depleted however the distribution patterns of trace elements are quite similar indicating that trace element speciation in oil shale is governed by general processes rather than by individual geochemical mechanisms within one particular sample the elements in the bilong co oil shale may be classified into three groups of association according to their modes of occurrence i e groups a b and c group a si al k na ti zr sc th sn nb ga ta be hf cs li rb ash rees is strongly correlated with ash yield and mainly has an inorganic affinity group b cr w mg mn br f sr ba has weakly or negatively positive correlation coefficients with an exception of f with ash yield group c zn bi cd ca fe pb hg co cu ni p mo se u as v shows negative correlation coefficients with ash yield with an exception of bi and possibly has an organic affinity

a hemispheric mechanism for the atlantic multidecadal oscillation abstract the physical processes associated with the 70 yr period climate mode known as the atlantic multidecadal oscillation amo are examined based on analyses of observational data a deterministic mechanism relying on atmosphere ocean sea ice interactions is proposed for the amo variations in the thermohaline circulation are reflected as uniform sea surface temperature anomalies in the north atlantic these anomalies are associated with a hemispheric wavenumber 1 sea level pressure slp structure in the atmosphere that is amplified through atmosphere ocean interactions in the north pacific the slp pattern and its associated wind field affect the sea ice export through fram strait the freshwater balance in the northern north atlantic and consequently the strength of the large scale ocean circulation it generates sea surface temperature anomalies with opposite signs in the north atlantic and completes a negative feedback the authors find that the time scale of the cycle is associated with the

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

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

geochemistry of terrestrial oil shale from the lunpola area northern tibet china abstract the lunpola oil shale is the largest oil shale resource in tibet twenty four samples of oil shale mudstone and dolomite were collected from the lunpola oil shale for mineralogical and trace element analyses the vertical distribution and mode of occurrence of trace elements in this terrestrial oil shale were also discussed oil shale samples from the lunpola area have high toc contents 5 1 10 6 high ash yields 74 8 84 7 low total sulfur contents 0 19 1 03 and high shale oil contents 5 0 10 3 the major minerals in the oil shale samples are clays quartz calcite and dolomite with minor quantities of feldspar siderite hematite magnesite and pyrite other minerals such as halite zeolite barite anhydrite and mirabilite were detected in some oil shale samples the contents of as ba be bi cd ce cs hg la li mo nd pb pr rb se sm th u w and zr are enriched from 1 30 to 125 times as compared to their average crust abundance clarke values whereas the other elements are slightly higher or lower than their respective clarke values compared to common australian oil shale the lunpola oil shales contain higher as ba be ce co cs ga gd hf nb nd pb pr rb sc sm sn th and zr but lower cd cu lu mo ni se sr u v and zn elements associated with organic matter and or fe sulfides are highly enriched in all oil shale deposits suggesting that their speciation in oil shale is governed by general processes e g high organic matter content and anoxic environment whereas elements associated with clay minerals exhibit various enrichments indicating that their speciation in oil shale is governed by individual geochemical mechanisms e g source rocks the elements in the lunpola oil shale may be classified into three groups of associations according to their modes of occurrence group a elements tio 2 sc hf zr be li w v zn sio 2 al 2 o 3 rb ga sn cr ta cs k 2 o th na 2 o rees and ash yield have high positive correlations with ash yield and a mainly inorganic affinity group b elements as toc mno ni fe 2 o 3 cd co cu mo se mgo bi pb and hg show a negative correlation with ash yield and most elements possibly have a likely organic affinity and or fe sulfide affinity group c elements sr cao u and p 2 o 5 show a weak or negligible correlation with ash yield with the exception of cao elements of environmental concern as bi hg mo pb se and u are present in high contents and are clustered in the second association i e they are hosted mainly in fe sulfides and or organic matter

brecciated and mineralized coals in union county western kentucky coal field abstract coals from the d 2 and d 3 boreholes in the grove center 7 1 2 min quadrangle union county ky have been found to be highly brecciated and mineralized the mineralization is dominated by a carbonate assemblage with minor sulfides and sulfates included among the secondary minerals is the lead selenide clausthalite overall the emplacement of secondary vein minerals was responsible for raising the rank of the coals from the 0 6 0 7 rmax range found in the area to as high as 0 95 0 99 rmax a 1 3 m thick coal found in one of the boreholes is unique among known western kentucky coals in having less than 50 vitrinite semifusinite and fusinite dominate the maceral assemblages the coal is also low in sulfur coal which is unusual for the illinois basin it has an ash yield of less than 10 much of it dominated by pervasive carbonate veining the age of the thick coal in core d 2 is similar to that of the elm lick coal bed found elsewhere in the western kentucky coalfield the coals in d 3 are younger having stephanian palynomorph assemblages

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

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

sedimentary control on the formation of a multi superimposed gas system in the development of key layers in the sequence framework abstract based on core observations well logs and test results of siderite bearing mudstone from the benxi formation to the member 2 of the shanxi formations in the linxing block northeastern ordos basin a logging identification model for siderite bearing mudstone key layer was established the porosity characteristics and sealing property were quantitatively evaluated by logging data sedimentary control on the formation of multi superimposed gas bearing system in the development of key layers in the sequence framework was also discussed the results showed that the siderite bearing mudstone has obvious logging response characteristics e g high photoelectric absorption cross section index pe high density den high amplitude natural gamma ray gr low acoustic ac low resistivity m2rx and low neutron porosity cncf the quantitatively evaluated results of the porosity characteristics and sealing property for the key layer showed that the key layer has the characteristics of low porosity with an average of 1 20 percent low permeability with an average of 2 29 10 8 m 2 and high breakthrough pressure with an average of 12 32 mpa in the study area this layer acts as an impermeable gas barrier in a multi superimposed gas system the results also indicated that the material composition of the multi superimposed gas bearing system can be established by the sequence stratigraphic framework the sedimentary evolution results in a cyclic rhythm of material composition vertically the spatial distribution of the corresponding transgressive event layer near the maximum flooding surface mfs in the sequence framework restricts the spatial distribution of the key layer with high breakthrough pressure and low porosity which constitutes the gas bearing system boundary the siderite bearing mudstone formed near the mfs in the second order sequence and constitutes a stable comparison of the first order gas bearing system boundary which has a wide range of regional distribution and stable thickness the siderite bearing mudstone formed near the mfs in the third order sequence is often incompletely preserved due to the late underwater diversion channel erosion and cutting this layer forms the coal bearing reservoirs which we termed as a second order gas bearing system in adjacent third order sequences to form a uniform gas bearing system

permo carboniferous paleogeography and coal accumulation and their tectonic control in the north and south china continental plates abstract permo carboniferous strata in north china and south china were essentially controlled by paleogeography paleoclimate and plate tectonics during that time north china and south china were separate microcontinents located on opposite sides of the equator thus the characteristics of their coal deposits differ substantially in north china the coal seams were initially deposited on a north sloping epicontinental basin during the middle carboniferous by the middle of the late permian the locus of coal formation had shifted from the north to the south as a result of the uplift of the northern margin due to continental collision with the siberian plate as the paleoplate was situated in the low northern latitudes moist tropical climate and favorable geographic setting allowed the extensive development of late carboniferous and earliest permian peat swamps on the northern alluvial fluvial plain and central paralic regimes more significantly two thick coal sequences were formed in the transition belt between the alluvial apron and fluvial plain and the shoreline area where high groundwatertable fed by both rainwater and groundwater favored the formation of thick peat in swamps with northward drift the paleoplate entered the subtropic semiarid and arid climatic belt between the late early permian and early late permian coal formation was restricted to the paralic delta plain where locally oceanic wet climate and high groundwatertable prevailed following this the subduction of the paleo tethys beneath the southern margin of north china led to the upwarp of the southern margin and kept the delta system growing vertically for a considerable period so that it kept pace with shoreline fluctuations on the southern area the result was that multicycle deltaic coals were well developed at this stage in south china coal was formed in the coastal zone of an epeiric and shelf sea which connected the marinal basins the basins were frequently influenced by plate marginal tectonic movements and continental rifting related to back arc extension as a result coal formation was often interrupted by sea level fluctuations early carboniferous coal was deposited during the short regressions during the widespread transgression mainly on the restricted marine paralic plain where clastic deposition was active in the middle and late carboniferous no coal was formed because the paleoplate had drifted into a subtropic arid belt early permian coal accumulated at first in the northeast and later in the southwest due to tectonic influences in the late permian relatively thick and extensive coal was formed even though it was during a transgressive period in both the western and eastern margins under the equatorial hot humid conditions in general the seam geometry and quality particularly ash and sulfur of the coal was directly controlled by the geography and the changes in the depositional environments however the fluctuation in coal formation and the migration of thicker coal zones was indirectly controlled by paleoclimate and the sea level fluctuations in response to plate tectonic influences

crocoite an unusual mode of occurrence for lead in coal abstract what is believed to be a very unusual mode of occurrence for lead in coal has been identified as crocoite pbcro4 as part of a larger study on trace elements and mineralogy in the cretaceous main seam in new zealand crocoite was found in raw coal samples within the lower part of the coal seam x ray diffraction xrd and bulk chemical data from a sem equipped with an energy dispersive x ray analyser edxa have confirmed the identity of this mineral this is apparently the first time that crocoite has been reported in coal crocoite usually occurs only in the oxidised zone of lead mineral deposits the occurrence of this mineral in the main seam coal implies that the deposit was exposed to an oxidising environment at some stage most likely after coalification

mineralogy and geochemistry of the no 6 coal pennsylvanian in the junger coalfield ordos basin china abstract this paper discusses the mineralogy and geochemistry of the no 6 coal pennsylvanian in the junger coalfield ordos basin china the results show that the vitrinite reflectance 0 58 is lowest and the proportions of inertinite and liptinite 37 4 and 7 1 respectively in the no 6 coal of the junger coalfield are highest among all of the late paleozoic coals in the ordos basin the no 6 coal may be divided vertically into four sections based on their mineral compositions and elemental concentrations a high boehmite content mean 6 1 was identified in the no 6 coal the minerals associated with the boehmite in the coal include goyazite rutile zircon and pb bearing minerals galena clausthalite and selenio galena the boehmite is derived from weathered and oxidized bauxite in the weathered crust of the underlying benxi formation pennsylvanian a high pb bearing mineral content of samples zg6 2 and zg6 3 is likely of hydrothermal origin the no 6 coal is enriched in ga 44 8 g g se 8 2 g g sr 423 g g zr 234 g g rees 193 3 g g hg 0 35 g g pb 35 7 g g and th 17 8 g g gallium and th in the no 6 coal mainly occur in boehmite and the pb bearing selenide and sulfide minerals contribute not only to se and pb contents in the coal but also probably to hg content a high zr content is attributed to the presence of zircon and sr is related to goyazite the rees in the coal are supplied from the sediment source region and the rees leached from the adjacent partings by groundwater

minerals in bituminous coals of the sydney basin australia and the illinois basin u s a although other forms of inorganic components may be significant in lower rank coals the mineral matter in most bituminous coals is dominated by silicates carbonates sulphides phosphates and other crystalline mineral groups these may be present in various forms including thin bands and laminae intimately associated with the organic matter as well as lenticles nodules crystal aggregates and cell infillings all of which indicate approximately contemporaneous formation with the peat bed other minerals however occur as veins or cleat and fracture fillings indicating precipitation after most of the compaction and presumably after most of the rank advance ome of the penecontemporaneous mineral matter is of detrital origin representing epiclastic or pyroclastic particles washed or blown into the peat swamp other mineral matter however including much of the pyrite quartz and siderite as well as abundant well crystallized kaolinite appears to have been formed by precipitation processes either within the swamp waters or in the pores of the peat deposit pyrite largely formed by bacterial reduction of dissolved sulphate ions seems to be related in abundance to marine transgressions which allowed permeation of sea water into the swamp and through the peat bed beneath siderite appears to form in the absence of sulphate rich sea water probably from co2 released by organic decay the clay fraction of the noncoal rocks in many coal bearing sequences is typically dominated by illite or interstratified clay minerals with kaolinite chlorite and possibly montmorillonite also present to a variable though typically minor extent although perhaps modified by chemical reactions or ion exchange mechanisms in the peat swamp these clay minerals may also be present in the coal as well especially near the base of top of the seam the kaolinite in the noncoal rocks is usually poorly crystallized and typically a minor constituent but well crystallized kaolinite is characteristically present and often the dominant component in the mineral fraction of bituminous coal beds as well as in some of the lutites including underclays intimately associated with the seams a progressive upward gradation to a particularly kaolinite dominated mineral assemblage occurs in some seams of the sydney basin australia this gradation is thought to be due to either increased blockage of detrital contaminants as the swamp developed or to in situ chemical or biological leaching of the mineral fraction and reconstitution of the residues in the upper parts of the peat bed superimposition of such cycles is also noted within the seam in some instances suggesting repetition of several phases of this type during major peat accumulations

quantification of mineral matter in the argonne premium coals using interactive rietveld based x ray diffraction abstract the mineral matter in the eight reference north american coal samples of the argonne premium coal series has been investigated on a quantitative basis using x ray diffraction xrd techniques x ray diffraction data obtained from electronic low temperature oxygen plasma ash lta residues from ashes produced by heating the coals in air at 370 c and also from the raw coals themselves were evaluated using an interactive data processing system siroquant based on rietveld interpretation methods the results from the three types of material lta 370 c ash and raw coal were compared for each sample this allowed the components present in the raw coals in crystalline form to be recognised separately from mineral artifacts produced particularly in the low rank coals from interaction of organically associated elements ca s etc during the two ashing processes after the allowance for the production of any artifacts the quantitative mineral assemblages identified from xrd of the raw coals were found to be consistent even for coals having a relatively low ash percentage around 5 with the results obtained from the respective mineral concentrates prepared by the ashing methods the effects of heating the coal to 370 c could also be distinguished relative to the raw coal or the lta through changes in components such as pyrite and the clay minerals although some areas of uncertainty exist particularly with magnesium in the low rank coals the calculated chemical compositions of the coal ash derived from the mineral mixtures identified for each coal were also found to be consistent with the results of direct chemical analysis of the respective coal ash materials

nature and distribution of phosphorus minerals in cook inlet coals alaska although phosphorus is a very important biogenic element its concentration in coal is generally low phosphorus concentrations typically range from 0 001 to 0 229 in raw coals of the contiguous 48 states of the u s a some alaskan coals in the cook inlet region contain horizons unusually high in phosphorus analyses of coals at 0 3 m intervals from a deep drill core containing 21 3 m of subbituminous c coal from the beluga coalfield alaska showed certain increments with as much as 17 03 p2o5 in the coal ash 1 01 p on a moisture free coal basis crandallite group minerals were identified by electron microprobe analyses as phosphorus rich minerals in these coals crandallite was found as 3 m size colloidal precipitates and as concretions and porous aggregates as large as 100 m calcium barium strontium and phosphorus concentrations in the coal attributable to crandallite group minerals can be quantified using chemical fractionation for exchangeable cations and acid extractable elements because high phosphorus horizons in cook inlet coals are attributed to periodic infusions of phosphorus from volcanic ash as well as the proper chemical environment for the precipitation of the phosphorus minerals it is suggested that the profiles of acid extractable phosphorus concentration may be useful to aid coal seam correlations

petrologic and geochemical characteristics of barkinite from the dahe mine guizhou province china abstract although barkinite has long been studied by many geologists its geochemical characteristics and environment of deposition are still not known in detail in order to study the petrography and geochemical characteristics of barkinite coal samples from two permian coal seams were taken from the dahe mine guizhou province the samples were separated into maceral fractions and then analyzed by microscopical isotopic rock eval and geochemical methods the microscopical results indicate that barkinite occurs as four main types according to their relationship to other maceral groups barkinite is ostensibly formed under variably dry wet or oxidizing reducing conditions the extract yield isotope data and rock eval values of barkinite are different from other macerals microscopical and geochemical results indicate that barkinite forms part of the liptinite group

geological controls on the mineralogy and geochemistry of the beypazari lignite central anatolia turkey abstract the raw coal from the cayirhan mine beypazari basin turkey contains an average of 28 5 mineral matter consisting up to 80 zeolites the coal seam is split by a 1 m thick tuffaceous siltstone into the upper first tv and lower second tb seams which contain essentially different zeolites the first seam contains ca rich zeolites clinoptilolite heulandite whilst the second seam contains na rich zeolites analcime experimental work has shown that a na rich activation solution will produce na rich zeolites when the original volcanic glass is na rich but will produce ca rich zeolites when the volcanic material is ca rich it is thought that a na rich activation solution derived from contemporaneous volcanics in the beypazari basin reacted with volcanic tuffs of different chemical composition to produce the vertical variability in the mineral matter of the two seams trace element analyses of the raw coal showed that they are enriched in as b cr ni and zr when compared to world wide averages of coal they are also enriched in the major elements na and k these elements are probably also derived from a volcanic source barium and sr show a clear affinity for analcime whilst li cr ni cu zn co and ga show a clear affinity for clinoptilolite heulandite trace elements showing a positive correlation with the organic matter are mn b be ge y zr nb hf w and u manganese u th sc ge and hree heavy rare earth elements show correlations with phosphate trace elements showing correlation with both fe and s contents are co mo ta pb and iree intermediate rare earth elements arsenic and v seem to have mixed affinities with sulphides and zeolites and organic matter and zeolites respectively although a proportion of the as b and s are retained in the ash during coal combustion due to the sorption mechanism of cao derived from the clinoptilolite heulandite decomposition significant emissions of these elements may arise from the cayirhan thermal power station due to the anomalously high concentrations of these elements in the beypazari coal the high total alkali metal content of these coals exceeds the recommended maximum for steam coal but it is believed that sodium occurring in a mineralogical form such as analcime is not as likely to contribute to boiler fouling as organically associated sodium

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

minerals and potentially hazardous trace elements in the late triassic coals from the qiangtang basin china abstract the tumen coal mine has the largest coal resources in tibet which have been developed and utilized as an important energy source in the last decades it has raised some health problems during the coal exploration and utilization in tibet fifty late triassic coal or coaly samples were picked up from the qiangtang basin tumen mine woruoshan and hongshuihe areas to determine the minerals potentially hazardous elements and their mode of occurrence and possible sources coal samples from the qiangtang basin have medium and high ash yields 15 20 47 88 with low or medium high total sulfur content 0 04 4 86 minerals in qiangtang basin coal include clay minerals dolomite quartz pyrite siderite and hematite and trace amounts of halite feldspar anhydrite barite chromite and galena potentially hazardous trace elements in coal samples include as hg pb and se arsenic is controlled mainly by aluminosilicate minerals mercury occurs mainly as an organic bound form the organically bound pb is dominant selenium is controlled mainly by fe bearing probably pyrite a proportion of the elevated concentrations of as hg pb and se in qiangtang basin coal may be related to underlying shale bed these elements might have been eroded or leached from the shale bed which were subsequently transported and accumulated syngenetically in the coal forming peat swamps the enrichment of as hg pb and se in qiangtang basin coal however is also partly to be related to magmatic hydrothermal fluids

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

coal rank trends in the western kentucky coalfield and relationship to hydrocarbon occurrence abstract vitrinite maximum reflectance trends for the middle pennsylvanian springfield no 9 coal bed in the western kentucky coalfield indicate that coal rank is high volatile a bituminous 0 70 0 85 rmax in portions of the webster syncline in webster and union counties south of the rough creek fault zone and is generally high volatile c bituminous 0 60 rmax in the remainder of the coalfield within the webster syncline the reflectance of the springfield coal does not vary significantly despite a difference in elevation of nearly 300 m reflectance gradients in the webster syncline are not well defined reflectances are generally highest in the baker no 13 coal bed and are lower in the underlying herrin no 11 and briar hill no 10 coals rank trends from the springfield data alone suggest pre tectonic coalification but the lack of well defined reflectance gradients complicates this interpretation hydrothermal alteration may have been a significant cause of the coalification in this region previous investigations of coals in fault blocks have considered the role of hydrothermal mineralization in coalification southern union and webster counties are adjacent to the fluorspar district a region of extensive hydrothermal metamorphism it is possible that convective heat transfer related to fluorspar district mineralization led to vertical heterogeneity in the temperature profile and consequent metamorphic history in henderson county north of the rough creek fault zone coal rank is significantly lower as low as 0 42 rmax for the springfield coal reflectance gradients are again poorly defined extensive oil and gas development has occurred in the high volatile c bituminous region to the north of the rough creek fault zone whereas fewer pools with lower production are known within the webster syncline to the south of the fault zone the rank of the middle pennsylvanian coals can be used to estimate the level of maturation of the devonian new albany shale a likely source rock for much of the oil and gas in the coalfield previous studies on the maturation of the new albany shale which lies about 1 km below the springfield coal indicate an equivalent medium volatile bituminous 1 0 1 2 rm rank in the fluorspar district new albany rank decreases to an equivalent high volatile b c 0 60 rm north of the rough creek fault zone the significance of the new albany reflectances is dependent on the level of suppression of vitrinite reflectance in organic rich shales the existence of reflectance suppression would imply that the shales could be more mature than studies to date have indicated it is possible that the episodes of basin dewatering which influenced the coal rank south of the rough creek fault zone also flushed the potential oil reservoirs in the same region