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

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

geochemistry mineralogy and technological properties of coals from rio maior portugal and penarroya spain basins abstract this study focuses on the geochemistry and mineralogy of pliocene lignites from the rio maior basin portugal and of late westphalian bituminous and anthracite coals from the penarroya basin spain major mineral phases present in the rio maior lignites are quartz and clay minerals with minor amounts of other detrital minerals depending on the sedimentary environment and the source of the detrital input the concentration of rb cs sc v u and gd in lignites is higher than the maximum value established for the usual worldwide concentration range for coal geochemical affinity study for major and trace elements in rio maior established three major associations i aluminium silicate affinity fe mg na k li rb sc zr v cr co ni se pb sb gd and tb ii the sulphur affinity mo and as and iii organic affinity sr ca mn ba and u ce and cs affinities could not be explained with the available data in the penarroya bituminous coals the main mineral phases identified were quartz and clay minerals kaolinite and illite minor traces of anatase and epigenetic carbonates elements with inorganic affinity fe mg na k ti li rb cs ba sc zr v cr co ni pb u se ce gd tb cu have a high to medium aluminium silicate affinity anomalous concentrations of li rb cs sc v and cr could be related to the input of detrital minerals from the precambrian and lower palaeozoic rocks in the northeastern part of penarroya basin anthracites from the penarroya basin have the following mineral phases calcium iron and magnesium carbonates clay minerals and quartz as well as traces of apatite and of pyrite carbonates and some kaolinite are clearly epigenetic as a consequence of fluid circulation related to magmatic activity two main geochemical associations were found i aluminium silicate affinity na k ti rb cs ba sc cr mo ni cd as sb se ce gd tb cu and ii carbonate affinity ca mg fe v mn sr an anomalous amount of mn and v is considered to be related with the circulation of magmatic fluids the geochemical and mineralogical variations observed were primarily related to coal rank in the penarroya basin whilst paleoenvironmental depositional conditions were more important in the rio maior basin the chemical composition of the high temperature ashes is related to the trend followed by the ash fusion temperatures and to the predictive indices associated with slagging and fouling propensities these indices indicate low to medium slagging and fouling propensities for all the coals studied

geochemistry mineralogy and technological properties of the main stephanian carboniferous coal seams from the puertollano basin spain this study is focused on the occurrence and distribution of mineral matter and major and trace elements in the high volatile bituminous coal from puertollano south central spain the relationship between ash behaviour and inorganic composition as well as the possible formation of fouling and slagging deposits in boilers during the conversion process were investigated the puertollano coals do not exhibit plastic properties despite their rank probably because of their high ash and inertinite contents the puertollano coal has medium to low total s content 0 48 to 1 63 db with a mean of 1 0 db and is characterised by relatively high contents of si pb sb and cs some elements such as as cd co cr cu ge li mn ni w and zn are also present in relatively high contents the enrichment in a number of heavy metals could be attributed to the common sulphide ores occurring near the puertollano coal deposit the following trace elements affinities are deduced a sulphide affinity as co cd cu ni sb tl and zn b aluminum silicate affinity k ti b co cr cs cu ga hf li nb rb sn ta th v zr and lree c carbonate affinity ca mg mn and b d organic affinity b the very high si levels and the anomalous enrichment in cs ge pb sb and zn shown by the puertollano coals account for the high contents of these elements in the puertollano fly ash when compared with the other spanish coal fly ashes the chemical composition of the high temperature ash hta is consistent with the trend shown by the ash fusion temperatures aft and also with the predictive indices related to slagging and fouling propensities thus the ash fusion temperatures increase with high values of al2o3 as well as with the decrease in fe2o3 cao and mgo

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

extensional inheritance and surface processes as controlling factors of mountain belt structure surface processes and inherited structures are widely regarded as factors that strongly influence the evolution of mountain belts the first order effects of these parameters have been studied extensively throughout the last decades but their relative importance remains notoriously difficult to assess and document we use lithospheric scale plane strain thermomechanical model experiments to study the effects of surface processes and extensional inheritance on the internal structure of contractional orogens and their foreland basins extensional inheritance is modeled explicitly by forward modeling the formation of a rift basin before reversing the velocity boundary conditions to model its inversion surface processes are modeled through the combination of a simple sedimentation algorithm where all negative topography is filled up to a prescribed reference level and an elevation dependent erosion model our results show that 1 extensional inheritance facilitates the propagation of basement deformation in the retro wedge and 2 increases the width of the orogen 3 sedimentation increases the length scale of both thin skinned and thick skinned thrust sheets and 4 results in a wider orogen 5 erosion helps to localize deformation resulting in a narrower orogen and a less well developed retro wedge a comparison of the modeled behaviors to the high atlas the pyrenees and the central alps three extensively studied natural examples characterized by different degrees of inversion is presented and confirms the predicted controls of surface processes and extensional inheritance on orogenic structure

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

geochemistry of beryllium in the mariza east lignite deposit bulgaria abstract beryllium geochemistry in coal has been studied on the basis of its distribution in 1556 individual full channels of coal coaly shales partings and lithotype samples from 11 profiles of the mariza east lignite deposit bulgaria this is the largest lignite deposit in bulgaria producing coal for three thermal power stations tps and a briquette plant the be content was determined in the coal ash 500 c by atomic emission spectrography at a detection limit of about 1 ppm be the mean be content for the different profiles ranged from 0 7 to 6 9 ppm be similar to that of global average for subbituminous coals higher concentrations of be were found in the first seam with thickness from 1 to 4 m whereas the second seam reached 24 m most of the xylain and vitrain samples showed lower be content than the whole coal samples from which they were selected the fusain samples were usually enriched in be compared to the whole coal samples and the other lithotypes which is a specific feature of the deposit distribution of be along vertical profiles follows that of ash beryllium in the lignite occurs predominantly in the inorganic matter as isomorphic admixtures and or adsorbed on the clay minerals a small portion is bound to the organic matter these conclusions were based on circumstantial evidence such as correlation with ash aluminium and germanium content distribution in lithotypes sink float and leaching experiments the low be content and its inorganic affinity are supposed to be the result of several factors negligible influx of be in solution in the swamp large dimensions of the basin great thickness of the main second seam and long distance from the source province

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

geochemistry of source rock controlled late triassic coal an example from the dabaoding coal mine in panzhihua sichuan province southwestern china abstract the geochemistry of source rock controlled coals from the late triassic daqiaodi formation in the dabaoding coal mine of the southwestern sichuan province was investigated a total of 15 coal samples 6 parting samples and 4 roof and floor rock samples from the d15 3 and d18 coals were subjected to proximate and ultimate analyses for coal quality by using lta xrd with siroquant software for minerals xrf for major element oxides icp ms for trace elements icp cct ms for as and se ise for f and a dma 80 analyzer for hg results indicate that the dabaoding d15 3 and d18 coals are classified as low ash and low volatile bituminous coal minerals in coals are dominated by quartz kaolinite illite and dolomite most trace elements in the dabaoding coals are depleted or at normal levels relative to chinese coals or world hard coals except for cr with slight enrichment the dabaoding coals and host rocks are characterized by weakly positive ce and y anomalies strongly positive gd anomalies and weakly negative eu anomalies based on paleogeographical mineralogical and geochemical evidence the sediment source rocks of the daqiaodi coal bearing strata are identified as the panzhihua trachyte at the top of the kangdian upland which exerted crucial impacts on the dabaoding coals

a mineralogical and geochemical study of three brazilian coal cleaning rejects demonstration of electron beam applications abstract the background and anthropogenic levels of hazardous elements in the surface soil of a coal mining area depend on the geological setting of the region and the underlying soil material but may also be influenced by water borne or aeolian transport of sediment from adjacent coal related waste piles very few studies have focused on the chemical and mineralogical composition of brazilian coal cleaning rejects ccrs which may represent significant sources of soil or water contamination in this study we have investigated the quantitative distribution of minerals and potentially hazardous elements in ccrs and a run of mine coal from the brazilian states of rio grande do sul and santa catarina the major minerals identified by x ray diffraction xrd high resolution transmission electron microscopy hr tem and field emission scanning electron microscopy energy dispersive x ray analysis techniques fe sem eds are kaolinite quartz mixed layer illite smectite pyrite jarosite melanterite gypsum rutile and calcite while minor minerals include barite hematite siderite sphalerite and goethite galena magnetite zircon and many other species may also occur as accessory trace minerals pyrite and jarosite are relatively abundant in some cases making up to around 4 or 5 of the mineral matter with jarosite melanterite and gypsum probably formed by complex interaction of oxidation products from fe sulfides and clay or carbonate components initiated by exposure and storage of the host material such atmospheric exposure promotes sulfide oxidation that releases substantial sulfate loads as well as ca 2 k mg 2 cl and al 3 metals with the most severe discharges were zn cu mn co ni and cd most of the trace pollutants in the ccrs displayed a ph dependent solubility being immobile in near neutral samples but mobile under the low ph conditions associated with oxidized material the results highlight the complex interactions among mineral matter components of the ccrs during storage and the potential for release of potentially hazardous elements in association with longer term exposure and storage

enrichment of u se mo re v in coals preserved within marine carbonate successions geochemical and mineralogical data from the late permian guiding coalfield guizhou china we present multi element data on the super high organic sulfur shos 5 19 on average coals of late permian age from guiding in guizhou province china the coals formed on restricted carbonate platforms are all highly enriched in s u se mo re v and cr and to a lesser extent ni and cd although the guiding coals were subjected to seawater influence boron is very low and mainly occurs in tourmaline and mixed layer illite smectite uranium mo and v in the coal are mainly associated with the organic matter in addition a small proportion of the u occurs in coffinite and brannerite the major carrier of se is pyrite rather than marcasite rhenium probably occurs in secondary sulfate and carbonate minerals the u bearing coal deposits have the following characteristics the formation age is limited to late permian concentrations of sulfur and rare metals u se mo re v and in some cases rare earth elements and y are highly elevated the u bearing coal beds are intercalated with marine carbonate rocks organic sulfur and rare metals are uniformly distributed within the coal seams and the combustion products e g fly and bottom ash derived from the coal deposits may have potential economic significance for rare metals u se mo re v rare earth elements and y

revisiting the late permian coal from the huayingshan sichuan southwestern china enrichment and occurrence modes of minerals and trace elements abstract the late permian coals from the huayingshan coalfield of southwestern china are significantly enriched in zr 695 g g nb 75 9 g g se 6 99 g g hf 10 1 g g and rare earth elements and y 1423 g g previous studies showed that the sediment source region for these coals was the kangdian upland which was formed at an early stage of the late permian period the source rocks have a basalt composition and those studies attributed the enrichment of the above high field strength elements hfses to derivation from the kangdian upland geochemical and mineralogical data presented in this study show that the dominant sediment source regions for the coal and roof strata of the huayingshan coalfields are the dabashan uplift hannan upland and leshan longnvsi uplift the highly elevated concentrations of hfses in the coals are due to hydrothermal fluids three tonstein layers derived from alkali rhyolite were identified these tonsteins are characterized by highly enriched hfses and by strong negative eu anomalies in the rare earth element distribution patterns the major carriers of the rare earth elements in the coal are rhabdophane and silicorhabdophane the latter of which is also enriched in zr zirconium however mainly occurs in zircon rhabdophane and silicorhabdophane in the coal are mainly distributed along the bedding planes and occur as cell fillings zircon in the coal occurs as cell fillings and is of authigenic origin anatase in the partings and coals contains nb and occurs as fracture filling and colloidal forms the modes of occurrence of the above minerals indicate that they were derived from hydrothermal fluids mercury and se mainly occur in sulfide minerals pyrite and marcasite

sulfur in coals a review of geochemistry and origins geochemical studies of sulfur in coals comprise several major aspects relating to the nature and origin of sulfur in coals including the abundance and distribution of sulfur in coal seams abundance of sulfur in coal lithotypes and macerals characteristics and geochemical significance of sulfur containing organic compounds sulfur isotopic studies relating to the sources of sulfur in coals and sedimentary environments controlling the geochemistry of sulfur in coal a review of the evidence suggests that the variation of sulfur in coals is closely related to the depositional environments of coal seams for low sulfur coal 1 s sulfur is derived primarily from parent plant material for medium sulfur 1 to 3 s and high sulfur 3 s coals there are two major sources of sulfur 1 parent plant material and 2 sulfate in seawater that flooded peat swamps abundances of sulfur in coal are largely controlled by the degree of seawater influence during peat accumulation and by postdepositional changes diagenesis in high sulfur coals seawater sulfate diffuses into the peat which is subsequently reduced by bacteria into hydrogen sulfide polysulfides and elemental sulfur reaction of hydrogen sulfide with ferrous iron generates fine pyrite crystals and mackinawite fes0 9 mackinawite reacts with elemental sulfur to converts to greigite fe3s4 and then to framboidal pyrite the reduced sulfur species in the peat hydrogen sulfide elemental sulfur and polysulfides react with the organic matter to form organic sulfur compounds during coal diagenesis nodular pyrite forms permineralized peat was formed during diagenesis which contains appreciable fraction of pyrite after coal is solidified pyrite can deposit in the cleats from circulating groundwater epigenetic pyrite veins may be deposited from basinal fluids thus pyrite forms during various stages of coal formation from peat to coal as well as late epigenetic activity the relationships between sulfur abundance in coal seams and depositional environments of coals were reviewed for cases from the u s china u k germany hungary turkey indonesia and brazil in most cases low sulfur coals formed in a fluvial environment and high sulfur coals were deposited in seawater influenced environments there are exceptions for example turkish lignites formed in freshwater environments are high sulfur sulfur sources other than seawater are needed for these high sulfur coals the superhigh organic sulfur shos coals are highly enriched in organic sulfur but depleted in pyritic sulfur the shos coals were deposited in sulfur rich iron poor environments such as carbonate platforms or in an iron poor and clastic starved environment in which algae accumulate speciation of organic sulfur compounds in coal appears to be related to coal rank thiophenic compounds are more abundant in bituminous coal and anthracite than in low rank coals

geochemistry of trace elements in coals from the zhuji mine huainan coalfield anhui china the abundances of nine major elements and thirty eight trace elements in 520 samples of low sulfur coals from the zhuji mine huainan coalfield anhui china were determined samples were mainly collected from 10 minable coal seams of 29 boreholes during exploration the b content in coals shows that the influence of brackish water decreased toward the top of coal seams marine transgression and regression occurred frequently in the lower shihezi formation a wide range of elemental abundances is found weighted means of na k fe p be b co ni cr se sb ba and bi abundances in zhuji coals are higher and the remainder elements are either lower or equal to the average values of elements in coals of northern china compared to the chinese coals the zhuji coals are higher in na k be b cr co se sn sb and bi but lower in ti p li v and zn the zhuji coals are lower only in s p v and zn than average u s and world coals potassium mg ca mn sr as se sb and light rare earth elements lree had a tendency to be enriched in thicker coal seams whereas fe ti p v co ni y mo pb and heavy rare earth elements hree were inclined to concentrate in thinner coal seams the enrichment of some elements in the shanxi or upper shihezi formations is related to their depositional environments the elements are classified into three groups based on their stratigraphic distributions from coal seams 3 to 11 2 and the characteristics of each group are discussed lateral distributions of selected elements are also investigated the correlation coefficients of elemental abundances with ash content show that the elements may be classified into four groups related to modes of occurrence of these elements

depositional history of the fire clay coal bed late duckmantian eastern kentucky usa more than 3800 coal thickness measurements proximate analyses from 97 localities and stratigraphic and sedimentological analyses from more than 300 outcrops and cores were used in conjunction with previously reported palynological and petrographic studies to map individual benches of the coal and document bench scale variability in the fire clay hazard no 4 coal bed across a 1860 km 2 area of the eastern kentucky coal field the bench architecture of the fire clay coal bed consists of uncommon leader benches a persistent but variable lower bench a widespread and generally thick upper bench and local variable rider benches rheotrophic conditions are inferred for the leader benches and lower bench based on sedimentological associations mixed palynomorph assemblages locally common cannel coal layers and generally high ash yields the lower bench consistently exhibits vertical variability in petrography and palynology that reflects changing trophic conditions as topographic depressions infilled infilling also led to unconfined flooding and ultimately the drowning of the lower bench mire the drowned mire was covered by an air fall volcanic ash deposit which produced the characteristic flint clay parting the extent and uniform thickness of the parting suggests that the ash layer was deposited in water on a relatively flat surface without a thick canopy or extensive standing vegetation across most of the study area ash deposits led to regional ponding and establishment of a second planar mire because the topography had become a broadly uniform nutrient rich surface upper bench peats became widespread with large areas of the mire distant to clastic sources vertical sections of thick 70 cm low ash yield upper coal bench show a common palynomorph change from arborescent lycopod dominance upward to fern and densospore produc ing small lycopod dominance inferred as a shift from planar to ombrotrophic mire phases domed mires appear to have been surrounded by wide areas of planar mires where the coal was thinner 70 cm higher in ash yield and dominated by arborescent lycopods rectangular

mineralogy and geochemistry of the coals from the chongqing and southeast hubei coal mining districts south china abstract this paper deals with the study of the late permian coal deposits from chongqing and south eastern hubei mining districts and of the late triassic coal deposits from chongqing mining district the late permian coals are characterized by relatively high amount of sulphide sulphate and carbonate minerals and by a high total content of trace elements with respect to the late triassic coals due to the marine influence on the depositional environment the late permian chongqing and the southeastern hubei coals showed similar geochemistry and mineralogy however there were some differences due to the different source rock and magmatic influence on hubei coals the concentrations of most trace elements in the late triassic coal were relatively low when compared with the usual range of the worldwide concentrations by contrast the contents of ta se nb sc hf tl bi cu v and zn in the late permian chongqing and southeastern hubei coals were higher than the usual range differences in occurrence of major and trace elements were found between late permian hubei and chongqing coals thus most of the trace elements investigated presented an aluminosilicate association followed by sulphide arsenide fe s as pb mo ni and co in most cases and carbonate ca and mg affinities in both areas however there was an important phosphate and zircon association in the chongqing coal whereas the carbonate association was significantly influenced by magma in the coals from hubei in the late triassic coal most of the major and trace elements investigated occur in aluminosilicate associations with the exception of s fe ca mn sr sn ba nb mo mg co and ta with carbonate sulphate and sulphide affinities

the geochemistry of environmentally important trace elements in uk coals with special reference to the parkgate coal in the yorkshire nottinghamshire coalfield uk abstract the parkgate coal of langsettian age in the yorkshire nottinghamshire coalfield is typical of many coals in the uk in that it has a high sulphur s content detailed information on the distribution of the forms of s both laterally and vertically through the seam was known from previous investigations in the present work 38 interval samples from five measured sections of the coal were comprehensively analysed for major minor and trace elements and the significance of the relationships established using both raw and centered log transformed data the major elements are used to quantify the variations in the inorganic and organic coal components and determine the trace element associations pyrite contains nearly all of the hg as se tl and pb and is also the major source of the mo ni cd and sb the clays contain the following elements in decreasing order of association rb cs li ga u cr v sc y bi cu nb sn te and th nearly all of the rb is present in the clay fraction whereas for elements such as v cu and u a significant amount is thought to be present in the organic matter based on the k vs trace element regression equations only ge and possibly be would appear to have a dominant organic source the trace element concentrations are calculated for pyrite the clay fraction and organic matter for pyrite it is noted that concentrations agree with published data from the yorkshire nottinghamshire coalfield and also that tl concentrations median of 0 33 ppm in the pyrite are greater than either hg or cd unlike these elements tl has attracted less attention and possibly more information is needed on its anthropogenic distribution and impacts on man and the environment a seawater source is thought to be responsible for the high concentrations of s cl and the non detrital trace elements in the parkgate coal indicative of the seawater control is the th u ratio which expresses the detrital to non detrital element contributions using other elements similar ratios can be calculated which in combination offer greater interpretative value

mineralogical and geochemical anomalies of late permian coals from the fusui coalfield guangxi province southern china influences of terrigenous materials and hydrothermal fluids abstract the late permian coal in the fusui coalfield of southern china is characterized by high fe sulfide and organic sulfur contents 2 60 and 2 94 respectively trace elements including zr 354 g g on average hf 9 18 g g y and rare earth elements rey 302 g g li 97 9 g g and cs 7 02 g g are significantly enriched in these coals in addition to hg and se enrichment in the roof and floor of the coal fluorine mo and u are enriched in the roof the floor is rich in cl s fe pb and cd compared to the upper continental crust rey in the parting and coal bench samples are characterized by heavy rey and light rey enrichment respectively the coals partings and host rocks roof and floor have negative eu anomalies the coal benches have higher ratios of u th yb la nb ta and zr hf and more abundant heavy rare earth elements than their adjacent partings these geochemical anomalies are attributed to the composition of terrigenous materials derived from the yunkai upland multi stage syngenetic and epigenetic hydrothermal fluid activities and intensive leaching and re distribution of lithophile elements from partings to the underlying coal benches both the organic and sulfide sulfur are also derived mainly from the hydrothermal fluids rather than the marine influence the minerals in the samples studied including kaolinite quartz and ree bearing minerals are of both terrigenous and hydrothermal origin al oxyhydroxides crystalline feso 4 oh water bearing fe oxysulfate and goyazite were derived from the hydrothermal activity kaolinite quartz ree bearing minerals and apatite from the sediment source region were also subjected to destruction by hydrothermal fluid leaching

elemental modes of occurrence in an illinois 6 coal and fractions prepared by physical separation techniques at a coal preparation plant abstract in order to gain better insight into elemental partitioning between clean coal and tailings modes of occurrence have been determined for a number of major and trace elements s k ca v cr mn fe zn as se pb in an illinois 6 coal and fractions prepared by physical separation methods at a commercial coal preparation plant elemental modes of occurrence were largely determined directly by xafs or mossbauer spectroscopic methods because the concentrations of major minerals and wt ash were found to be highly correlated for this coal and derived fractions rendering correlations between individual elements and minerals ambiguous for inferring elemental modes of occurrence of the major elements investigated iron and potassium are shown to be entirely inorganic in occurrence most 90 of the iron is present as pyrite with minor fractions in the form of clays and sulfates all potassium is present in illitic clays calcium in the original coal is 80 90 inorganic and is divided between calcite gypsum and illite with the remainder of the calcium present as carboxyl bound calcium in the clean coal fraction organically associated ca exceeds 50 of the total calcium this organically associated form of ca explains the poorer separation of ca relative to both k and ash among the trace elements v and cr are predominantly inorganically associated with illite but minor amounts 5 15 cr 20 30 v of these elements are also organically associated estimates of the v and cr contents of illite are 420 ppm and 630 ppm respectively whereas these elements average 20 and 8 ppm in the macerals arsenic in the coal is almost entirely associated with pyrite with an average as content of about 150 ppm but some as 10 is present as arsenate due to minor oxidation of the pyrite the mode of occurrence of zn although entirely inorganic is more complex than normally noted for illinois basin coals about 2 3 is present in sphalerite with lesser amounts associated with illite and a third form yet to be conclusively identified the non sulfide zinc forms are removed predominantly by the first stage of separation rotary breaker whereas the sphalerite is removed by the second stage heavy media germanium is the only trace element determined to have a predominantly organic association

high quality of jurassic coals in the southern and eastern junggar coalfields xinjiang nw china geochemical and mineralogical characteristics abstract the junggar coal basin with enormous coal reserves is one of the largest coal basins in xinjiang province northwest china according to the exploration data there is one to dozens of workable coal seams developed in the xishanyao formation of middle jurassic across the whole basin with the maximum accumulated coal thickness of over 100 m ninety six bulk coal samples from six exploration boreholes in the southern and eastern junggar coalfields were collected to investigate the coal qualities of the junggar coals the mineralogical characteristics of the studied coals were determined by powder x ray diffraction xrd and geochemical analyses are performed by means of inductively coupled plasma atomic emission spectrometry icp aes and inductively coupled plasma mass spectrometry icp ms the eastern and southern junggar bituminous coals are all characterized by low ash yields low s contents and low mineral contents furthermore the concentrations of most major and trace elements in both the eastern and southern junggar coals are relatively low with respect to other chinese and worldwide coals with the exceptions of sr and ba the results show that elements including k li ti sc v cr ga rb zr pb and rare earth elements rees have aluminosilicate affinities ca bearing and fe bearing carbonate affinities are deduced for ca mg fe mn sr and ba sulfur fe zn pb cu and as show a partial sulfide affinity in some coals an apatite and or crandallite affinity is deduced from relatively high correlation of p sr and ba the very high coal quality of junggar coals is attributed to very low detrital supply in very stable shallow lake sedimentary facies during peat accumulation slight differences of peat bog accumulation rate water table and oxidizing reducing condition account for the merging and splitting of coal seams in different coal exploration areas and the slight differences of mineral s ash and trace element contents in summary the eastern and southern junggar coals with very enormous reserves are characterized by high quality which is significantly and environmentally relevant to coal combustion by products ccps and potential emissions of gaseous pollutants particulate matter during the large coal consumption in pulverized coal combustion power stations in xinjiang province the high coal quality of the junggar coals is expected to generate ccps that can be reused for various purposes with low environmental threat

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

petrology mineralogy and geochemistry of the ge rich coal from the wulantuga ge ore deposit inner mongolia china new data and genetic implications abstract the early cretaceous wulantuga high ge coal deposit in inner mongolia is one of the major coal hosted ge deposits in china this paper reports new data on the petrological mineralogical and geochemical compositions of 13 bench samples of the high ge no 6 coal from the wulantuga deposit and provides new insight into the origin and modes of occurrence of the minerals and elements present the no 6 coal has a low rank ro max 0 45 and is a low ash coal 8 77 the total content of inertinite 52 5 vol on average in most coal benches is higher than that of huminite 46 8 vol on average the dominant huminite maceral is textinite averages 43 9 and the dominant inertinite macerals are mainly fusinite averages 33 and semifusinite 12 5 along with trace portions of intertodetrinite secretinite funginite and macrinite fungus seen as the maceral funginite played a role in the development of degraded maceral forms in the wulantuga coals funginite is present in samples examined in this study but is not easily extracted during palynological studies recovered fungal taxa are saprophytes indicating woody decomposition prior to incorporation in the mire palynology revealed a sparse flora that is consistent with the early cretaceous age minerals in the coal include quartz kaolinite illite and or illite smectite gypsum pyrite and traces of rutile and anatase a varying proportion of bassanite was observed in the low temperature ashes ltas bassanite in the ltas was derived both from the dehydration of gypsum in the raw coals and from the interaction between organically associated ca and s during the low temperature ashing in addition to a proportion of detrital quartz fine grained and cell filling quartz of authigenic origin is also present pyrite is of syngenetic origin and derived from sulfate rich hydrothermal fluids compared to common chinese and world low rank coals the no 6 coal is enriched in be 25 7 g g f 336 g g ge 274 g g as 499 g g sb 240 g g cs 5 29 g g w 115 g g hg 3 165 g g and tl 3 15 g g germanium in the coal is organically associated and its enrichment is attributed to hydrothermal fluids from the adjacent granitoids beryllium is probably associated with ca and mn bearing carbonate minerals and to a lesser extent with clay minerals rather than with organic matter fluorine largely occurs in clay minerals kaolinite and illite the elevated concentrations of tl hg as and sb are mainly distributed in pyrite and were derived from the same hydrothermal source the high w in the coal occurs in both the organic matter and the authigenic quartz illite is the major carrier of cs in the coal the accumulation of rare earth elements ree in the coals had a polygenetic and multistage nature including two syngenetic stages early hydrothermal and terrigenous and one diagenetic late hydrothermal stage the ree distribution patterns of the early hydrothermal and terrigenous stages were characterized by the enrichment of medium ree m type ree and light ree l type ree respectively a h type ree distribution pattern hree enrichment occurred in the late diagenetic hydrothermal stage the high ge wulantuga coals are also abnormally enriched in precious metals gold pt and pd in the coals calculated from their concentrations in the ltas are 3 5 25 8

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

elemental and mineralogical anomalies in the coal hosted ge ore deposit of lincang yunnan southwestern china key role of n2 co2 mixed hydrothermal solutions abstract the lincang neogene high ge coal deposit in yunnan southwestern china is one of the major coal hosted ge deposits in the world this study reports new data on the petrological mineralogical and geochemical compositions of 57 samples including coal bench samples roofs floors partings and batholith granite of three high ge coal seams s3 z2 and x1 from the dazhai mine lincang ge ore deposit and provides new insights into the origin and modes of occurrence of the minerals and elements present the coals have huminite random reflectances in the 0 33 0 48 range on a mineral free basis the coal samples are dominated by huminite group macerals all having more than 88 5 total huminite ulminite and attrinite generally dominate the huminite macerals structured inertinite is rare with funginite being the most abundant inertinite form the minerals in the coals are mainly composed of quartz and to a lesser extent kaolinite illite and mica a hydrous beryllium sulfate phase beso 4 4h 2 o is present in the low temperature ashes of several coal samples compared to average values for world low rank coals beryllium up to 2000 g g and 343 g g on average ge up to 2176 g g and 1590 g g on average and w up to 339 g g and 170 g g on average are unusually enriched in the lincang coals with a concentration coefficient 100 cc ratio of element concentration in investigated coals vs world low rank coals elements as 156 g g on average sb 38 g g cs 25 2 g g and u 52 5 g g are significantly enriched 10 the biotite and two mica granites which served as both the basement for the coal bearing sequence and as a source of sediment input were also either hydrothermally altered or argillized the alteration appears to have taken place during or shortly after deposition of the coal bearing sequence two types of metasomatites of hydrothermal origin including quartz carbonate and carbonate were identified which occur as partings and as roof and floor strata these metasomatites were formed at the syngenetic or early diagenetic stages of coal deposition the rare earth elements in these hydrothermal rocks are characterized by a heavy ree enrichment type and by distinct positive eu anomalies compared to the upper continental crust hydrothermal solutions have played a significant role in producing the elemental and mineralogical anomalies in the lincang ge ore deposit the hydrothermal solutions leaching the batholith granite were a mixture of alkaline n 2 bearing and volcanogenic co 2 bearing fluids which led to the enrichment of trace elements not only including assemblages of ge w and be nb u both leached from granite and the deposited in the peat but also as sb from volcanogenic solution as well as the alteration and argillization of the batholith granites and the formation of carbonate and quartz carbonate metasomatites

geochemical distribution of trace elements in kaffioyra and longyearbyen coals spitsbergen norway abstract paleogene bituminous coals of low rank r aver 0 63 and 0 69 respectively occurring in two spitsbergen norway regions longyearbyen and kaffioyra were analyzed to find occurrence and distribution of the following trace elements be cd co cr cu li mn mo ni pb v zn inductively coupled plasma atomic emission spectrometry icp aes was used for ash derived from combusted coals their extracts and macromolecular fractions trace element concentrations were investigated to find occurrence variability and a degree of trace element affinity to organic and inorganic coal fraction in the coals from both regions maceral and elemental composition of these coals was also determined kaffioyra and longyearbyen coals show significant differences in the composition of their organic and mineral matter reflected both in petrographic properties and elemental compositions the kaffioyra coals are characterized by higher contents of vitrinite group macerals lower contents of inetrinite group macerals and lower concentrations of carbon hydrogen and sulphur the kaffioyra coals show higher content of clay minerals and carbonates than the longyearbyen coals trace element contents in ash of coals from both spitsbergen regions are below the average contents of these elements in the world s bituminous coals coals of both regions differ in trace element concentration and their occurrence variability the main carrier of trace elements in coals of both regions is ash of biogenetic and sorptive origin while in the range of high concentrations of trace elements terrigenic input also plays an important role

geochemistry of rare earth elements in permian coals from the huaibei coalfield china abstract the rare earth elements rees in coals are important because of a ree patterns can be an indicator of the nature of source rocks of the mineral matter as well as sedimentary environments b rees abundance in coal may have industrial significance in this study a total of thirty four samples of permian coal partings roof and floor were collected from the huaibei coalfield anhui province china abundances of rare earth elements rees and other elements in the samples were determined by inductively coupled plasma mass spectrometry icp ms and inductively coupled plasma atomic emission spectrometry icp aes the results show that the rees are enriched in coals in the huaibei coalfield as compared with chinese and u s coals and the world coal average coals in the lower shihezi formation no 7 5 and 4 coals and upper shihezi formation no 3 have higher ree abundances than the coals in shanxi formation no 10 magmatic intrusion resulted in high enrichment of rees concentrations in no 5 and 7 coals the ree abundances are positively correlated with the ash content the mineral matter in these coals is mainly made up of clay minerals and carbonates the rees are positively correlated with lithophile elements including si al ti fe and na which are mainly distributed in clay minerals indicating that rees are contained mainly in clay minerals the ree abundances in coals normalized by the ash are higher than that in partings rees abundances of coals cannot be accounted for by the ree content in the mineral matter and some rees associated with organic matter in coals

mineralogy and geochemistry of late permian coals from the donglin coal mine in the nantong coalfield in chongqing southwestern china abstract the donglin coal mine an important mine in the nantong coalfield in southwestern chongqing is immediately adjacent to the songzao coalfield to investigate the mineralogy and geochemistry of donglin coals profile channel samples from the mineable nos 4 and 6 coals were collected the minerals major element oxides and trace elements were analyzed by lta xrd in combination with siroquant software xrf icp ms icp cct ms as and se ise f and dma 80 hg analyzer hg the results indicate that the donglin low volatile bituminous coals were characterized by low ash yields and high total sulfur contents the minerals varied between the nos 4 and 6 coals differentiated by montmorillonite calcite ankerite and pyrite despite the low boron concentration donglin coals were influenced by brackish water during coal accumulation selenium 10 9 mg kg f 431 mg kg hg 0 350 mg kg nb 20 7 mg kg and ta 3 68 mg kg in the no 4 coals and f 425 mg kg be 7 11 mg kg ga 14 5 mg kg ge 22 5 mg kg zr 218 mg kg nb 35 5 mg kg and ta 4 42 mg kg in the no 6 coals are slightly enriched four vertical distributions of elements were demonstrated i e roof floor roof and floor and middle enrichments the slightly enriched trace elements and ucc normalized rey distribution patterns of the donglin coals jointly eliminated the impact of various volcanic ashes and terrigenous input from the kangdian oldland during the late permian however the roof rock samples shared the geochemical feature of mafic tonstein enriched sc v cr co and ni while the floor rock of the no 6 coals resembles alkali tonsteins enriched ga zr nb ta hf and rey lithium ga zr ag cd in sn cs hf bi th and u occurred in kaolinite and or montmorillonite in the no 4 coals while li nb ag cd in cs ba and th occurred in kaolinite in the no 6 coals vanadium sr and mo in the no 4 coals and sr and sc in the no 6 coals were associated with calcite and or ankerite arsenic se hg sb and tl and hg and mo were associated with pyrite in the nos 4 and 6 coals respectively lithium be ge and sb in the no 4 coals and be and ge in the no 6 coals might be of organic affinity

mineralogy and geochemistry of al hydroxide oxyhydroxide mineral bearing coals of late paleozoic age from the weibei coalfield southeastern ordos basin north china abstract this paper mainly describes mineralogy and geochemistry of coals from the weibei coalfield in the southeastern ordos basin north china a number of al hydroxide oxyhydroxide minerals were detected in the late carboniferous coals nos 5 10 and 11 coals especially in the no 10 coal aluminum hydroxide oxyhydroxide minerals nordstrandite boehmite and diaspore in the no 10 coal are associated with kaolinite suggesting that these minerals are derived from the breakdown of kaolinite a model in which al hydroxide oxyhydroxide minerals form from the incongruent dissolution of kaolinite is presented nordstrandite and boehmite mainly occur as massive lenses n 2 mainly occurs within al hydroxide oxyhydroxide minerals nordstrandite boehmite and diaspore kaolinite and organic matter

ge distribution in the wulantuga high germanium coal deposit in the shengli coalfield inner mongolia northeastern china abstract the geological and geochemical controls of the ge distribution in the cretaceous wulantuga high germanium coal deposit in the shengli coal field inner mongolia are investigated this paper focuses mainly on the spatial distribution of the ge contents in coal the high ge coals mainly occur in three splits of the 6 coal in the southwestern part of the shengli coal field mean germanium contents in the coal range from 32 to 820 g g with a mean value of 137 g g on a bulk coal basis mean of 939 coal samples from 75 boreholes in the 6 coal seam in an area of 2 2 km 2 the highest ge content occurs sw of 6 coal seam close to the margins of the coal basin decreasing with a fan shaped trend towards nw the direction of the coal basin there is an negative correlation between the mean ge content and the thickness of the coal seam different distribution patterns of ge content were found in vertical profiles high ge concentrations may occur in the middle parts of coal seams at the bottom and or the top of thick coal seams and inconspicuous variation a major organic affinity was determined for ge with a special enriched in the banded bright and semibright coal the high ge coals and the coalified wood in the sandstone overlaying the 6 1 coal highly enriched in ge as sb w cs tl be and hg the late jurassic silicified volcanic rocks in the nw of the ge coal deposit relatively high enriched in ge ga sb as cs be ge and hg the correlation coefficients among the elements enriched showed marked variations at close sites in this deposit suggesting a possible diagenetic origin of the geochemical anomaly the main ge anomaly was attributed to early cretaceous hydrothermal fluids circulating through the fault systems and porous volcanic rocs probably from the subjacent granitoid rocks the fault systems the porous coarse clastic rocks overlying coal seam and the lithotype of coal played an important role in the transport and trapping of ge a main diagenetic origin overlapping a slight synsedimentary accumulation is deduced for the ge anomaly

mineralogical and geochemical compositions of the pennsylvanian coal in the adaohai mine daqingshan coalfield inner mongolia china modes of occurrence and origin of diaspore gorceixite and ammonian illite abstract aluminum hydroxide boehmite rich pennsylvanian coals of high volatile a bituminous rank were found previously in the jungar coalfield inner mongolia china this paper reports new results on 48 bench samples of the cp2 coal from the adjacent adaohai mine daqingshan coalfield inner mongolia and provides new insights into the origin and modes of occurrence of the minerals and elements present in the cp2 coal compared to the same coal in the adjacent mines the cp2 coal in the adaohai mine has a higher rank ro ran 1 58 which is attributed to igneous intrusions during the late jurassic and early cretaceous epochs the proportion of inertinite 35 3 in the coal is higher than that in other late paleozoic coals in northern china but lower than that in the jungar coals minerals in the cp2 coal include diaspore boehmite gorceixite calcite dolomite siderite clay minerals kaolinite and ammonian illite and trace amounts of anatase fluorapatite quartz and pyrite based on mineral proportions in the coal bench samples the cp2 coal may be divided into four zones i to iv from bottom to top the major mineral in zones i and iv is kaolinite zones ii and iii are mainly composed of ammonian illite diaspore boehmite gorceixite calcite dolomite and siderite diaspore boehmite and gorceixite forming materials were derived from oxidized bauxite in the weathered crust of the benxi formation in the sediment source region during peat accumulation however gorceixite may have formed earlier than diaspore the diaspore was derived from gibbsite that was subjected to dehydration by the heat of the igneous intrusions the ammonian illite may have been formed at a relatively high temperature by interaction of kaolinite with nitrogen released from the organic matter in the coal during metamorphism caused by the igneous intrusion the calcite and dolomite occur as epigenetic cell and fracture fillings and were probably derived from the igneous fluids compared to the common chinese and world coals the cp2 coal is enriched in cao 1 69 mgo 0 32 p2o5 0 214 f 207 g g ga 16 3 g g zr 446 g g ba 276 g g hg 0 33 g g and th 12 4 g g but has a lower sio2 al2o3 ratio due to the higher proportions of diaspore boehmite and gorceixite in the coal the f occurs mainly in gorceixite and fluorapatite the major carriers of ga are diaspore and kaolinite but not gorceixite barium mainly occurs in gorceixite and barite mercury was probably derived from the igneous intrusion and is distributed in both the organic matter and the minerals the elements are classified into five associations by cluster analysis groups a b c d and e group a represents a ree be y se ga ge sc in pb bi nb ta tio2 w hg sb zr hf th u association most of the elements in group a are lithophile elements that occur in aluminosilicate minerals group b sn te zn cd v as cr cu mo ni re is weakly correlated with ash yield and is associated with unidentified trace sulfide minerals elements in group c ad na2o al2o3 sio2 li k2o rb cs tl association probably occur in the clay minerals and diaspore group d consists of p2o5 ba f sr s and cl and with the exception of s they occur in minerals gorceixite and fluorapatite oxides of fe2o3 mno cao mgo make up group e and mainly occur in the carbonate minerals the coals are enriched in light rees and the lrees hrees have been highly fractionated with an average la yb n of 8 71 the heavy rees in the coals have a stronger organic affinity than the lrees

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

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

enrichment of u re v cr se and rare earth elements in the late permian coals of the moxinpo coalfield chongqing china genetic implications from geochemical and mineralogical data abstract rare metals in coal deposits have attracted much attention in recent years because of their potential economic significance this paper reports the abundance and enrichment origin of rare metals in the late permian coals k1 and k2 coals of the moxinpo coalfield chongqing southwestern china the k1 coal is characterized by highly elevated concentrations of u re v cr se and nb ta zr hf ree assemblages the latter assemblage is also enriched in the k2 coal the high temperature ash 815 c of the k1 coal is enriched in v cr se re u and ree the ash of the k2 coal and also the floor strata of each seam are enriched in ree potentially making all of the units economically viable sources for these elements the minerals in the k1 coal are mainly represented by kaolinite illite and mixed layer illite smectite and pyrite while the minerals in the k2 coal consist mainly of kaolinite and tobelite nh 4 k al 2 alsi 3 o 10 oh 2 authigenic roscoelite k v 3 al 2 alsi 3 o 10 oh 2 is commonly observed in the k1 coal under the sem and was probably formed by interaction of kaolinite with v derived from permeating u re v cr se rich solutions during early diagenesis the tobelite enriched in the k2 coal was formed by reaction between kaolinite already present in the coal and nh 4 derived from decomposition of the organic matter during hydrothermal alteration at a relatively high temperature the mafic tuffs directly underlying the k1 coal and containing limestone residual breccias not only served as the substrate for coal accumulation but also as the source of sediment from the uplifted areas around the coal basin the latter is indicated by low al 2 o 3 tio 2 ratios from 10 09 to 14 24 positive eu anomalies enrichment of medium rare earths relative to upper continental crust and detrital calcite of terrigenous origin the highly elevated concentrations of u re v cr se assemblages in the coal were derived from exfiltrational hydrothermal solutions and were then deposited in a euxinic environment the terrigenous materials in the k2 coal however were derived from felsic intermediate rocks at the top of the kangdian upland although the elevated concentrations of nb ta zr hf ree assemblages are attributed to the input of hydrothermal solutions

geochemistry of environmentally sensitive trace elements in permian coals from the huainan coalfield anhui china abstract to study the geochemical characteristics of 11 environmentally sensitive trace elements in the coals of the permian period from the huainan coalfield anhui province china borehole samples of 336 coals two partings and four roof and floor mudstones were collected from mineable coal seams major elements and selected trace elements were determined by inductively coupled plasma optical emission spectrometry icp oes inductively coupled plasma mass spectrometry icp ms and hydride generation atomic absorption spectrometry haas the depositional environment abundances distribution and modes of occurrence of trace elements were investigated results show that clay and carbonate minerals are the principal inorganic constituents in the coals a lower deltaic plain where fluvial channel systems developed successively was the likely depositional environment of the permian coals in the huainan coalfield all major elements have wider variation ranges than those of chinese coals except for mg and fe the contents of cr co ni and se are higher than their averages for chinese coals and world coals vertical variations of trace elements in different formations are not significant except for b and ba certain roof and partings are distinctly higher in trace elements than underlying coal bench samples the modes of occurrence of trace elements vary in different coal seams as a result of different coal forming environments vanadium cr and th are associated with aluminosilicate minerals ba with carbonate minerals and cu zn as se and pb mainly with sulfide minerals

petrological organic geochemical and geochemical characteristics of coal from the soko mine serbia abstract a petrological organic geochemical and geochemical study was performed on coal samples from the soko mine soko banja basin serbia ten coal and two carbonaceous clay samples were collected from fresh working faces in the underground brown coal mine from different parts of the main coal seam the lower miocene low rank coal of the soko mine is a typical humic coal with huminite concentrations of up to 76 2 vol liptinite less than 14 vol and inertinite less than 11 vol ulminite is the most abundant maceral with variable amounts of densinite and clay minerals sporinite and resinite are the most common macerals of the liptinite group inertodetrinite is the most abundant maceral of the inertinite group the mineral bituminous groundmass identified in some coal samples and carbonaceous marly clay indicate sub aquatic origin and strong bacterial decomposition the mean random huminite reflectance ulminite b for the main coal seam is 0 40 0 05 rr which is typical for an immature to early mature stage of organic matter the extract yields from the coal of the soko banja basin ranges from 9413 to 14 096 ppm in which alkanes constituted 1 0 20 1 aromatics 1 3 14 7 asphaltenes 28 1 76 2 and resins 20 2 43 5 the saturated hydrocarbon fractions included n c15 to n c32 with an odd carbon number that predominate in almost all the samples the contents of n c27 and n c29 alkanes are extremely high in some samples as a contribution of epicuticular waxes from higher plants acyclic isoprenoid hydrocarbons are minor constituents in the aliphatic fraction and the pristane phytane pr ph ratio varies between 0 56 and 3 13 which implies anaerobic to oxic conditions during sedimentation the most abundant diterpanes were abietane dehydroabietane and 16 h phyllocladane in samples from the upper part of the coal seam diterpanes are the dominant constituents of the alkane fraction polycyclic alkanes of the triterpane type are important constituents of alkane fractions the occurrence of and type hopanes from c27 to c31 but without c28 is typical for the soko banja coals the major and trace elements in the coal were analysed using x ray fluorescence xrf and inductively coupled plasma mass spectrometry icp ms in comparison with world lignites using the geometric mean value the coal from the soko banja basin has a high content of strontium 306 953 mg kg higher values than the world lignites were obtained for mo 3 614 mg kg ni 8 119 mg kg se 0 884 mg kg u 2 642 mg kg and w 0 148 mg kg correlation analysis shows inorganic affinity for almost all the major and trace elements except for s which has an organic affinity

variations in elemental and mineralogical compositions of late oligocene early and middle miocene coal seams in the kale tavas molasse sub basin sw turkey abstract the kale tavas sub basin which is the south western part of the lycian molasse basin sw turkey hosts several coal seams of late oligocene early and middle miocene age within respectively the mortuma yenidere and sekkoy formations this study aims to determine coal rank mineralogical and geochemical features of the coal seams and to ascertain factors controlling the mineralogical distribution and elemental enrichment the distinct differences among the studied coal seams refer to mean random huminite vitrinite reflectance rr the highest rr values 0 63 0 69 are measured on the late oligocene tavas coal whereas the lowest rr values 0 26 0 27 were recorded in the middle miocene narli coal similar mineralogical assemblages were found in all the studied coal seams however aluminosilicate minerals are dominant to abundant phases in the coal from the mortuma and yenidere formations while carbonate minerals are the dominant phases in the coal from the sekkoy formation accordingly aluminosilicate related elements e g al k ti and li display relatively higher concentrations in the studied coal seams from the mortuma and yenidere formations whereas relatively high ca concentrations and depletion of aluminosilicate affiliated elements were recorded in the coal of the sekkoy formation furthermore ni mo and u are relatively enriched in all the studied seams while relative b enrichment is identified in the coal seams of the mortuma and yenidere formations and these seem to be related to possible marine influence of the palaeomires during late oligocene and early miocene and or the occurrence of specific b bearing aluminosilicate minerals also u and mo enrichments in the narli coal may be related with the development of anoxic conditions within the palaeomires during the middle miocene other indicators for anoxic conditions are framboidal pyrite grains and accessory ni bearing iron sulphides in all the studied samples although coal bearing formations in the kale tavas sub basin deposited under different sedimentary environment as the source areas for sediment supply of the coal seams remained the same during the late oligocene to early miocene the mineralogical composition and elemental enrichment of the coal were mainly controlled by clastic inputs and redox conditions within the palaeomires to a lesser extent a possible marine influence might have contributed to elemental enrichment

mineralogical and geochemical compositions of the coal in the guanbanwusu mine inner mongolia china further evidence for the existence of an al ga and ree ore deposit in the jungar coalfield abstract aluminum hydroxide boehmite and diaspore ga rey rare earth elements and y and al rich pennsylvanian taiyuan formation coals have previously been found in the jungar and daqingshan coalfields inner mongolia china gallium rey and al are potentially extractable and usable elements in combustion residues derived from these coals this paper reports new results on 50 bench samples of the no 6 coal from the guanbanwusu mine jungar coalfield inner mongolia and provides new data and evidence for the existence of an al ga rey ore deposit in the unique jungar coalfield the no 6 coal in the guanbanwusu mine has a low rank ro ran 0 56 and a low sulfur content st d 0 58 the proportion of inertinite in the coal 56 7 mineral free basis is higher than that of vitrinite 31 the minerals in the coal are mainly represented by kaolinite boehmite and chlorite along with variable proportions in some samples of calcite ankerite siderite and goyazite boehmite goyazite and part of the kaolinite were derived from bauxite in the weathered surface of the sediment source region ankerite calcite and siderite in the coal are of authigenic origin the chlorite in the guanbanwusu coals appears to have a chemical composition intermediate between cookeite and chamosite this mineral mainly occurs as cell fillings also indicating an authigenic origin and was probably derived from hydrothermal fluids a new mineral phase mainly composed of ti cl and fe is probably a ti bearing oxychloride or hydroxychloride compared to other chinese coals and to world hard coals the coal from the guanbanwusu mine is enriched in al2o3 9 34 p2o5 0 126 li 175 g g f 434 g g cl 1542 g g ga 12 9 g g sr 703 g g and th 12 9 g g but has a lower sio2 al2o3 ratio 0 74 due to the higher proportions of boehmite and goyazite in the coal the major carrier of p2o5 and sr is goyazite lithium mainly occurs in the chlorite cf cookeite kaolinite and possibly to a lesser extent illite fluorine in the coal has a major boehmite affinity but a small proportion may also occur in the organic matter and chlorite gallium in the coal largely occurs in goyazite chlorine is independent of other elements in the coal associated neither with moisture nor with organic matter but possibly occurring in molecular form cl2 and in the ti bearing oxychloride or hydroxychloride thorium in the coal occurs in the clay and accessory minerals and was mainly derived from detrital materials of the source region rare earth elements and y have a mixed organic and inorganic affinity largely occurring in goyazite group minerals and to a lesser extent boehmite and organic matter most coal benches and partings have either an l type or h type of rey enrichment owing respectively to the weathered bauxite source region and groundwater effects the al2o3 ga rey and possibly li in the guanbanwusu coals like those in coals from the jungar and adjacent daqingshan coalfields are industrially useful metals that could potentially be recovered from the relevant coal combustion residues it is suggested that if ga in ash 50 g g rey 800 900 g g sio2 al2o3 40 in ash and coal thickness 5 m the coal combustion residues would be expected to be suitably enriched in al2o3 and can be considered for al2o3 ga and rey recovery

controls on boron and germanium distribution in the low sulfur amos coal bed western kentucky coalfield usa abstract the duckmantian aged amos coal bed is a thin geochemical analysis of the amos coal bed shows higher concentrations of b and ge than other western kentucky coal beds high total b concentrations as well as high b be both considered to be indicators of marine environments increase toward the top of the coal bed most of the b values for the amos samples range from 66 to 103 ppm whole coal basis indicating deposition in a brackish environment high ge concentrations in coals have been considered to be a function of seam thickness and proximity to the top and bottom of the coal bed thin coals such as the amos are dominated by the coal bed margins and therefore have a tendency to have relatively high ge concentrations in the case of the amos coal bed the lower bench has a higher ge content suggesting that the substrate was a more important source of ge than the roof rock

determination of elemental affinities by density fractionation of bulk coal samples from the chongqing coal district southwestern china abstract the occurrence and distribution of major and trace elements have been investigated in two coal bearing units in the chonqing mining district south china the late permian and late triassic coals the late permian coals have higher s contents than the late triassic coals due to the fixation of pyrite in marine influenced coal forming environments the occurrence of pyrite accounts for the association of a large number of elements fe s as cd co cu mn mo ni pb sb se and zn with sulphides as deduced from the analysis of the density fractions the marine influence is probably also responsible for the organic association of b the rees zr nb and hf are enriched by a factor of 2 3 with respect to the highest levels fixed for the usual worldwide concentration ranges in coal for these elements the content of these elements in the late permian coal is higher by a factor of 5 10 with respect to the late triassic coal furthermore other elements such as cu p th u v and y are relatively enriched with respect to the common range values with maximum values higher than the usual range or close to the maximum levels in coal the content of these elements in the late permian coal is higher than the late triassic coal these geochemical enrichments are the consequence of the occurrence in relatively high levels of phosphate minerals such as apatite xenotime and monazite as deduced from the study of the density fractions obtained from the bulk coal the late triassic coal has a low sulphur content with a major organic affinity the trace element contents are low when compared with worldwide ranges for coal in this coal the trace element distribution is governed by clay minerals carbonate minerals and to a lesser extent by organic matter and sulphide minerals major differences found between late permian and triassic coals are probably related to the source rocks given that the main source rock of the late permian epicontinental marine basin is the emeishan basalt formation characterised by a high phosphate content

a statistical approach to the study of the distribution of trace elements and their organic inorganic affinity in lower gondwana coals of india abstract trace element analyses of seventy six coal samples representing all the major lower gondwana coal basins of india were carried out eighteen trace elements viz b ba co cr cu ga ge la mn mo nb ni pb sn sr v y and zr were determined quantitatively in coal ash an attempt was made to correlate the coals of different coalfields on the basis of multivariate analysis in addition the organic inorganic affinities between the trace elements were established by the coefficients of correlation between the trace elements and ash present a synthesis of the data reveals that there is similarity in the concentration ranges of trace elements among the coal seams of different coalfields but the possibility of environmental differences exists due to the statistically different multivariate means of the trace element concentrations it is inferred that ge cr y and la occur in these coals as organo metallic complexes and chelates the elements ni co ga v and cu show both organic and inorganic association whereas mn and ba are exclusively incorporated in the inorganic fractions

the petrography mineralogy and geochemistry of a paleocene lignite from southern saskatchewan canada abstract the coal petrology mineralogy and elemental composition was determined on the 5 m thick lignite of the estevan seam bienfait mine southwest saskatchewan organic petrology reveals a dominance of huminite macerals 73 with minor liptinite 7 and inertinite 11 macerals the maceral assemblage and the banded nature of the coal suggests a forest moor depositional environment for the lignite optical and scanning electron microscopy and x ray diffraction reveals that the dominant mineralogy of the coal is quartz and carbonates with minor sulfates the roof parting and floor rock are dominated by quartz and clays with minor feldspars elemental concentration is rather uniform with depth most elements are associated with the mineral matter and increase with increasing ash content the elements b na sr and br are associated with the organic portion of the coal some elements show both a mineral and organic association as ba co fe mo ce dy lu w u the high concentrations of certain elements na b ca is attributed to groundwater circulation which can both introduce and remove elements from the porous lignite

field observations of recent transgression on northern and eastern melville island western canadian arctic archipelago abstract after 11 000 years of glacio isostatically induced forced regression geomorphological evidence indicates that the coastline of eastern melville island western canadian arctic archipelago is now being transgressed recently developed coastal features associated with this transgression include drowned gullies and small estuaries barriers and lagoons barrier islands erosional notches backstepping beaches and drowned tundra vegetation and vehicle tracks dating from the 1970s we mainly attribute this relative sea level rise to the eastward migration of a peripheral crustal forebulge furthermore the reported transgression also includes a component from recent eustatic sea level rise during the 20th century recent earthquakes recorded in the gustav lougheed arch seismic zone located in byam martin channel 70 km east of melville island suggest that neotectonics could also be involved in local relative sea level adjustments other factors associated with global warming especially the formation of an earlier shore ice lead coupled with increased storm activity might also be responsible for some of the coastal changes our study indicates that the current zero isobase separating areas of net transgression from those of net regression is now located off the east coast of the island our field observations support recent glacio isostatic modelling that shows the island is presently undergoing a transgression

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

mineralogical and geochemical responses of coal to igneous intrusion in the pansan coal mine of the huainan coalfield anhui china the huainan coalfield where magma is commonly intruded into the coal measures in the northern section e g the zhuji dingji pansan and panbei mines is the largest energy base in eastern china to investigate the mineralogical and geochemical responses of coal to igneous intrusion minerals major and trace elements in sandstone thermally altered coal igneous rock sandy mudstone and unaltered coal samples were collected from a representative profile of the no 1 coal of the pansan coal mine the samples were analyzed using an optical microscope powder x ray diffraction scanning electron microscopy in conjunction with x ray energy dispersive spectroscopy x ray fluorescence inductively coupled plasma atomic emission spectrometry and mass spectrometry the results indicated that the thick sill transformed from mafic rocks at the bottom via intermediate rocks in the middle to felsic rocks at the top of the profile the moisture total sulfur and carbon contents of the coal increased whereas volatile matter hydrogen and nitrogen decreased during contact metamorphism caused by igneous intrusion epigenetic minerals i e dolomite quartz and pyrite occurred in the thermally altered coals three stages of hydrothermal fluids i e ca mg and fe rich si rich and fe and or h2s rich solutions were identified iron ca s si mg zn cd and pb were transported into the thermally altered coal by hydrothermal fluids the concentrations of co and ni in the thermally altered coal increased in relation to the increase of ash yields that were caused by contact metamorphism whereas the b in the coal was volatilized manganese is directly related to the intrusive magma phosphorus ge and sr might be introduced into the coal by groundwater however k na ga and ba were leached out titanium sc cr v cu zr nb and rare earth elements and yttrium rey in the coals originated from terrigenous input and were not influenced by igneous intrusion

mineralogy and geochemistry of the late permian coals in the huayingshan coal bearing area sichuan province china abstract the mineralogical and geochemical characteristics of the late permian huayingshan coals partings roof and floor strata as well as lutitic rocks from the longtan formation in sichuan province southwestern china were investigated in this study the huayingshan low volatile bituminous coals are characterized by relatively high mineral contents mainly kaolinite quartz pyrite and calcite the concentrations of most trace elements are relatively high compared with other chinese and world coals the coals and associated strata show similar element affinities al ti li ta th ga u sn sc cr cu rb co and se probably have an aluminosilicate affinity zr nb hf y rees and u probably result from the occurrence of heavy minerals such as zircon s fe w and rb mainly have a sulfide affinity ca sr and mn mainly have an carbonate affinity the high enrichment in the huayingshan coal of zr nb hf rees ta ga and th is caused by a geochemical anomaly in the source of this coal s detrital material and probably also by input of volcanic ash which is influenced by the alkaline volcanic magmas of the emeishan basalt the zr hf zr nb zr la and zr th ratios support the volcanic origin of such a geochemical anomaly

the influence of geological factors on the concentration of boron in australian and canadian coals abstract the concentration of boron in australian and canadian coals determined using atomic emission spectrometry aes inductively coupled plasma spectrometry icp aes and prompt gamma ray spectrometry is summarized in order to assess the variation of b content in coal with respect to rank age geological setting in seam and stratigraphic and the degree of paleosalinity of the coal forming environment this study indicates that no or very complex relations exist between boron and rank subbituminous to anthracite variations of b with ash content for canadian coals of different age devonian to oligocene eocene indicate that the b content of coals is not governed by the age of the coal there is some evidence of variation of b with maceral content in canadian coals particularly as related to the inertinite and vitrinite content of coals the b content of coal seams is sensitive to the environment of deposition with b contents remaining relatively stable and within the range of values designated for each depositional setting however b values may show variation in the same seam laterally due to changes of the environment of deposition and or the enrichment of b by a secondary source the vertical variation of b in a coal bearing section or strata is related to depositional environment and lithology of rock there is often little variation in b content for coal layers as compared to the partings dirt bands the b content of partings in a coal bearing strata may vary greatly as compared to the coal seams after reappraising earlier work and on the basis of more recent studies on australian and canadian coals it is proposed that the following ranges of values for b in coal indicate the degree of marine influence during the early stages of coalification up to 50 ppm b freshwater influenced coals 50 110 ppm b mildly brackish water influenced coals 110 ppm b brackish water influenced coals using these criteria assessments are given for the degree of marine influence on canadian and australian coals

mineralogical and geochemical compositions of the pennsylvanian coal in the hailiushu mine daqingshan coalfield inner mongolia china implications of sediment source region and acid hydrothermal solutions abstract this paper investigates the mineralogical and geochemical compositions of the pennsylvanian coal in the hailiushu mine daqingshan coalfield neighboring previously reported al ga ree ore deposits including the adaohai mine in the same coalfield and deposits in the jungar coalfield using optical microscopy field emission scanning electron microscopy x ray fluorescence and inductively coupled plasma mass spectrometry the mineralogical and geochemical compositions in the coal were primarily controlled by the sediment source region during peat accumulation and by epigenetic acid hydrothermal solutions the hailiushu coal was deposited in a sub depression intermontane basin in the inner part of the orogenic belt with a sediment source region composed mainly of cambrian ordovician strata and archaean metamorphic rocks the minerals in the coal from the hailiushu mine dominantly consist of kaolinite with minor amounts of quartz sulfide and selenide minerals including chalcopyrite selenian galena galena sphalerite clausthalite and siegenite aluminophosphates and rhabdophane the coal is enriched in sio2 17 05 on average tio2 0 60 al2o3 13 71 zr 289 g g hf 7 09 g g and to a lesser extent f sc v cu ga se y nb mo cd sn la ta w hg pb bi and th titanium largely occurs in the kaolinite elements such as cu se sn hg pb and bi in the coal mainly occur in sulfide and or selenide minerals zirconium hf and nb were largely derived from the sediment source region the substitution of ti for al in kaolinite the corrosion of previously formed zircon anatase and quartz and the enrichment of middle rare earth elements in the coal were caused by the epigenetic acid hydrothermal solutions

scandium sc geochemistry in coals siberia russian far east mongolia kazakhstan and iran abstract this research discusses new original data on the geochemistry of scandium sc in the coals of the asian region of russia mongolia kazakhstan and iran in general the studied coals are enriched in sc compared with the mean value for coals throughout the world in different regions of the studied territory coal deposits with anomalous sc concentrations up to commercially important concentrations were found and the factors that control the sc contents in those coals were revealed the composition of the rock types that surround the coal forming basins and the hydro geochemical conditions of these basins and deposits determine the levels of sc accumulation in the coals it was found that sc was redistributed and partially lost from the seams during coal metamorphism studies of the modes of sc occurrence in the coals showed the predominance of an organic mode in addition the peculiarities of the sc distribution in the deposits and coal seams indicate a predominantly hydrogenous mechanism for the accumulation of anomalous sc concentrations in coal and peat scandium in coal and peat accumulates by leaching from coal bearing strata and re deposition in coal peat beds with the participation of soil and ground water enriched with organic acids specific conditions for the formation of coal containing sc enriched rocks and for the sc leaching and transportation into coal seams are necessary for the accumulation of high sc concentrations in the coals such conditions that occur in the contemporary mire ecosystems of western siberia could also have occurred in ancient basins of peat coal accumulation

enrichment of arsenic lead and antimony in balingian coal from sarawak malaysia modes of occurrence origin and partitioning behaviour during coal combustion abstract the concentrations of mineral forming elements and trace elements in coal and coal ashes from balingian coalfield sarawak malaysia were assayed and their modes of occurrence enrichment origin and partitioning behaviour during coal combustion were studied as well balingian coal is high in as cu pb sb th and zn of particular concern are as as high as 181 ppm pb 325 ppm and sb 96 ppm all of which are highly enriched in balingian coal relative to their respective coal clarke values arsenic pb and sb in the coal are mostly organic and to a lesser extent they are bound to discrete minerals in the form of aluminosilicates during coal combustion in the power plant a substantial portion of organically associated as pb and sb in the coal vaporize and are released into the atmosphere whereas ba and mn are highly enriched in the coal ashes as compared to the raw coal the as pb and sb anomalies observed in balingian coal may be related to a large sb as and probably pb mineralization in the vicinity of the coalfield with some localised epigenetic infiltration of these elements from the surrounding rocks by circulating groundwaters

mineralogy and geochemistry of the coals from the karmozd and kiasar coal mines mazandaran province iran abstract the karmozd and kiasar mines are two major coal producing areas in the central alborz coal bearing field northern iran this study focused on the mineralogy and geochemistry with respect to the mode of occurrence of elements in feed coals and element partitioning during coal preparation the low sulfur content in the coal seams indicates a non marine origin i e deposition in lacustrine and swamp environments detrital minerals in the coal seams are quartz feldspar albite and orthoclase mica muscovite and biotite amphibole hornblende and kaolinite authigenic minerals include pyrite calcite and chlorite the contents of most elements are within the general worldwide ranges with the exceptions of mn co and cr in some coal seams correlation coefficients between elements and the ash yield identified four separate groups of elements the sequential extraction results indicate that al na k zn cu and co principally occur in the silicates whereas pb and cr mainly occur in the organic fraction calcium and mg display strong affinities to the carbonate phase while cd mainly occurs in the water soluble and organic fractions the calculated removability index shows that the coal cleaning method in zirab not only removes mineral matter and pyritic sulfur but also reduces the content of most inorganic elements

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

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

whole coal versus ash basis in coal geochemistry a mathematical approach to consistent interpretations abstract several standard methods require coal to be ashed prior to geochemical analysis researchers however are commonly interested in the compositional nature of the whole coal not its ash coal geochemical data for any given sample can therefore be reported in the ash basis on which it is analyzed or the whole coal basis to which the ash basis data are back calculated basic univariate mean variance distribution etc and bivariate correlation coefficients etc measures of the same suite of samples can be very different depending which reporting basis the researcher uses these differences are not real but an artifact resulting from the compositional nature of most geochemical data the technical term for this artifact is subcompositional incoherence since compositional data are forced to a constant sum such as 100 or 1 000 000 ppm they possess curvilinear properties which make the euclidean principles on which most statistical tests rely inappropriate leading to erroneous results applying the isometric logratio ilr transformation to compositional data allows them to be represented in euclidean space and evaluated using traditional tests without fear of producing mathematically inconsistent results when applied to coal geochemical data the issues related to differences between the two reporting bases are resolved as demonstrated in this paper using major oxide and trace metal data from the pennsylvanian age pond creek coal of eastern kentucky usa following ilr transformation univariate statistics such as mean and variance still differ between the ash basis and whole coal basis but in predictable and calculated manners further the stability between two different components a bivariate measure is identical regardless of the reporting basis the application of ilr transformations addresses both the erroneous results of euclidean based measurements on compositional data as well as the inconsistencies observed on coal geochemical data reported on different bases

estimations of clarkes for carbonaceous biolithes world averages for trace element contents in black shales and coals abstract black shale and coal clarke values are the average trace element contents in the world black shales and coals these calculations are made in russian geochemistry but up to now are poorly known in the west modern tables of black shale and coal clarkes are presented based on comprehensive calculations using very large amount of information thousands analyses of black shales coals and coal ashes for trace elements in black shale geochemistry three figures were calculated for each main lithologies terrigenous tuff chert and carbonate two clarke estimations are presented named lithological k1 and lithostratigraphical k2 in coal geochemistry seven figures were calculated for each trace element average content in hard coals and their ashes average content in brown coals and their ashes average content in all coals and their ashes and coal affinity index or coalphile index average content in all ashes clarke values of sedimentary rocks the black shale and coal clarkes presented here provide an important scientific base for many geochemical comparisons and issues

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

geological controls on the quality of coals from the west shandong mining district eastern china abstract the basic coal quality parameters coal petrology mineralogy and geochemistry were investigated for coal seams 2 3 and 4 permian shanxi formation and 11 12 13 and 15 carboniferous taiyuan formation of the xinwen and feicheng coal fields in the west shandong mining district east china rank parameters indicate a high volatile c to b bituminous rank for the shandong coal coal from the zhaizhen and cha zhuang mines is characterised by high vitrinite and low middle inertinite and liptinite contents inertinite contents show an increase towards the top of the stratigraphic sequence from coal seams 15 13 and 11 to coal seams 4 and 2 this trend may be related to a stratigraphic trend characterised by the evolution of relatively more reducing conditions of the synsedimentary coal forming environment in the early taiyuan coals marine influenced lower delta plain to more oxidising paleoenvironments of the upper shanxi coal seams upper delta plain major mineral phases present in the shandong coal are quartz kaolinite pyrite and calcite traces of other primary minerals dolomite ankerite illite opal feldspars and marcasite and weathering products gypsum melanterite and hematite can be found in several coal seams the lower permian coal seams two to four have a lower mineral content 8 14 ash db than the upper carboniferous coal seams 15 37 ash db owing to the lower proportions of quartz and sulphide mineral the occurrence and distribution of the different minerals in the shandong coal indicates a paragenetic sequence characterised by an early syngenetic stage detrital minerals framboidal euhedral and massive cell filling pyrite ankerite neomorphic quartz and kaolinite middle and late syngenetic stages radial and fibrous marcasite aggregates massive pyrite and an epigenetic stage carbonates and sulphides as cleat filling a clear differentiation exists between the shanxi and the taiyuan coal seams based on the higher sulphide contents of the taiyuan coal 3 3 to 6 2 s db compared with the shanxi coal 0 4 to 0 8 s db this differentiation is related to marine influence on the depositional environment of coal seams 11 to 15 which has been reported by earlier studies vertical variations of the abundance of major and trace elements are discussed on the basis of this differentiation an epigenetic external enrichment of ge mo and u at the top of most of the coal seams is observed and major and trace element affinities are deduced for the west shandong coal

distribution of environmental sensitive trace elements in the eocene sorgun coals turkey abstract the distribution of trace elements in the lower eocene coal seam mined in the yeniceltek kucukkohne and ayridam coal mines from the sorgun basin was investigated in relation to ash content and maceral composition the coal seam is mainly composed of huminite in the present study 35 samples from five seam sections were collected on the basis of megascopic characteristics results were determined using an energy dispersive polarised x ray fluorescence edp xrf spectrometer on a whole coal dry basis most of the major and trace elements studied are enriched in high ash samples while ba br mn and w show relative enrichments in low ash samples most of elements studied such as ga ce la th nb rb zr v cu u pb sb cs sn cr se y and zn are primarily associated with mineral matter clay minerals arsenic and a part of zn se and sb are probably concentrated in pyrites in the samples element concentrations show statistically significant negative correlations with many macerals and positive relationships with only attrinite that is mainly mixed with mineral matter clay minerals and small quartz grains in the samples nine trace elements as cr mn ni pb sb se th and u considered as potentially hazardous air pollutants are present in low to moderate concentrations the mean values of trace element concentrations display relative enrichments in se 2 8 ppm th 21 ppm and w 26 ppm in the investigated samples in comparison with other coals in the world

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

geochemistry of boron in bulgarian coals a set of 466 individual full channel samples coals coaly shales and partings of thirteen bulgarian coal deposits as well as vitrain lenses gagatite and coalified woods embedded in sedimentary rocks have been analyzed by atomic emission spectroscopy the deposits consist of lignites subbituminous and bituminous coals the average boron content ranges from 15 to 164 ppm in the coals the boron content of the individual coal samples ranges from 2 to 164 ppm about 86 of the samples have a b content from 2 to 110 ppm which corresponds to the most probable interval of concentration for coals worldwide the boron content is not related to rank the lignites have the lowest boron content some of the vitrain and xylain samples studied are enriched in boron in comparison with the whole coal samples boron occurs in both organic borg and inorganic binorg forms excluding one deposit the boron content in the ash correlates negatively with the ash content whereas in coals it usually slightly increases with increasing ash content organically associated b dominates in the low ash coals and in the deposits enriched in boron the coals of the burgas deposit have the highest b content which is in agreement with the geological evidence for marine influence during the early stages of coalification the distribution of b is also independent of other geological factors

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

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

modes of occurrence of mercury and other trace elements in coals from the warrior field black warrior basin northwestern alabama abstract the mineralogic residence and abundance of trace metals is an important environmental issue data from the usgs coal quality database show that potentially toxic elements including hg as mo se cu and tl are enriched in a subset of coal samples in the black warrior basin of alabama usa although the coal as mined typically is low in these elements localized enrichments occur in high pyrite coals and near faults microscopic analyses demonstrate that the residence of these elements is dominantly in a late stage pyrite associated with structurally disrupted coal further our data suggest addition of hg to the coal matrix as well the source of these trace elements was hydrothermal fluids driven into the black warrior basin by alleghanian age tectonism

gallium and germanium in selected indiana coals abstract the distribution of gallium ga and germanium ge was studied in two pennsylvanian high volatile bituminous coals of indiana the springfield coal member of the petersburg formation and the danville coal member of the dugger formation gallium in the springfield and danville coals shows similar ranges from 1 70 to 8 90 ppm averaging 5 06 ppm for the danville coal and 1 40 to 12 30 ppm with an average of 3 39 ppm for the springfield coal for ge these ranges are 2 50 to 26 70 ppm average 14 19 ppm for the danville coal and 1 54 to 38 0 average 9 40 ppm for the springfield coal in the vertical section ga shows a symmetric distribution with the lowest values in the middle part of the seam in the springfield coal and an asymmetric distribution increasing or decreasing upward in the danville coal gallium is dominantly associated with the mineral matter and clay minerals in particular germanium shows a symmetric distribution with the largest enrichment in the topmost and the basal benches of the coal it appears to be associated with either mineral matter dominantly clays occasionally pyrite or organic matter

mineralogy and geochemistry of boehmite rich coals new insights from the haerwusu surface mine jungar coalfield inner mongolia china abstract boehmite rich coal of pennsylvanian age was discovered earlier at the heidaigou surface mine jungar coalfield inner mongolia china this paper reports new results on 29 bench samples of the no 6 coal from a drill core from the adjacent haerwusu surface mine and provides new insights into the origin of the minerals and elements present the results show that the proportion of inertinite in the no 6 coal is higher than in other late paleozoic coals in northern china based on mineral proportions boehmite to kaolinite ratio and major element concentrations in the coal benches of the drill core the no 6 coal may be divided into five sections i to v major minerals in sections i and v are kaolinite sections ii and iv are mainly kaolinite with a trace of boehmite and section iii is high in boehmite the boehmite is derived from bauxite in the weathered surface benxi formation in the sediment source region the no 6 coal is rich in al2o3 8 89 tio2 0 47 li 116 g g f 286 g g ga 18 g g se 6 1 g g sr 350 g g zr 268 g g rees 172 g g pb 30 g g and th 17 g g the elements are classified into five associations by cluster analysis i e groups a b c d and e group a ash sio2 al2o3 na2o li and group b ree sc in y k2o rb zr hf cs u p2o5 sr ba ge are strongly correlated with ash yield and mainly have an inorganic affinity the elements that are negatively or less strongly correlated with ash yield with exceptions of fe2o3 be v and ni are grouped in the remaining three associations group c se pb hg th tio2 bi nb ta cd sn group d co mo tl be ni sb mgo re ga w zn v cr f cu and group e s as cao mno fe2o3 aluminum is mainly distributed in boehmite followed by kaolinite the high correlation coefficients of the li ash li al2o3 and li sio2 pairs indicate that li is related to the aluminosilicates in the coal the boehmite rich coal is high in gallium and f which occur in boehmite and the organic matter selenium and pb are mainly in epigenetic clausthalite fillings in fractures the abundant rare earth elements in the coal benches were supplied from two sources the bauxite on the weathered surface of the benxi formation and from adjacent partings by groundwater leaching during diagenesis the light rare earth elements lrees are more easily leached from the partings and incorporated into the organic matter than the heavy rees leading to a higher ratio of lrees to hrees in the coal benches than in the overlying partings