Partitioning of elements and macerals during preparation of Antaibao coal

Analyses of the macerals, ash, sulfur and 43 major and trace elements were performed on samples of feed coal, cleaned coal, middlings and slime collected from the Antaibao coal preparation plant, China, and also on samples from coal preparation experiments. This study is focused on the partitioning of elements and macerals during coal preparation and potential environment aspects of the elements.The conclusions are as follows: (1) in comparison with the feed coal, the cleaned coal has a higher vitrinite content and relatively lower inertinite and exinite contents, whereas the middlings and slime have lower vitrinite and exinite contents, and relatively higher inertinite contents. The vitrinite contents in the size-segregated cleaned coals were observed to show a slightly increasing tendency with increasing particle size, while the inertinite contents decreased. (2) Physical coal cleaning is not only effective for removal of ash and sulfur, but also in reducing the concentration of most elements. As, Cd, Co, Cs, Hg, Fe, K, Mg, Nb and Ni are observed to show a high degree of removal, while Br, Be, Cu, U, Mn, Zn and organic sulfur are enriched in the cleaned coal and show a lower degree of removal. The large-sized cleaned coal is cleaner than the smaller sized fractions. (3) The middlings, especially the slime, are enriched in S, Hg, Cr, V, Zn, etc., so that these fractions should not be directly used as fuel. In addition, the concentration of Pb and V in the process water exceeds the limit of relevant environmental water quality standard. Consequently, it is necessary to develop new processes to remove ash, sulfur and hazardous trace elements to the maximum extent. Further studies on deep processing of the middlings and slime and cleaning of the process water should also be performed.     

Concentration and distribution of trace elements in some coals from Northern China

The concentration, distribution and modes of occurrence of trace elements in thirty coals, four floors and two roofs from Northern China were studied. The samples were collected from the major coalfields of Shanxi Province, Shaanxi Province, Inner Mongolian Autonomous Region, and Ningxia Hui Autonomous Region. The concentrations of seventeen potential hazardous trace elements, including Hg, As, Se, Pb, Cd, Br, Ni, Cr, Co, Mo, Mn, Be, Sb, Th, V, U, Zn, and five major elements P, Na, Fe, Al, and Ca in coals were determined.Compared with average concentration of trace elements in Chinese coal, the coals from Northern China contain a higher concentration of Hg, Se, Cd, Mn, and Zn. They may be harmful to the environment in the process of combustion and utilization. Vertical variations of trace elements in three coal seams indicated the distributions of most elements in coal seam are heterogeneous. Based on statistical analyses, trace elements including Mo, Cr, Se, Th, Pb, Sb, V, Be and major elements including Al, P shows an affinity to ash content. In contrast, Br is generally associated with organic matter. Elements As, Ni, Be, Mo, and Fe appear to be associated with pyrite. The concentrations of trace elements weakly correlate either to coal rank or to maceral compositions.     

吉林白山地区原煤微量元素地球化学特征

对吉林白山地区煤矿主采煤层中的As、B、Ba、Cd、Cu、Hg、Pb、Se、Sr等微量元素进行了分析,结果表明:太原组与山西组由于成煤环境不同,微量元素组成及其质量分数存在一定的差异,太原组原煤中As、B、Hg、Pb、Se、Zn的质量分数明显高于山西组,山西组原煤中Ba、Cr、Cu、Mn、V的质量分数明显高于太原组。白山地区原煤中As、B、Hg、Pb、Se的质量分数明显高于地壳元素平均值,呈富集状态;Co、Cd与地壳平均值接近,其他元素均亏损。与全国煤中微量元素的质量分数平均值相比,As、Ba、Co、Cr、Cu、Hg、Ni、Pb、Se、V、Zn的质量分数高于全国平均值。B、Mn、Sr质量分数低于全国平均值。微量元素赋存状态及相关分析表明,Fe与亲硫有害元素As、Cu、Hg、Pb、Se具有显著相关关系,说明煤中黄铁矿及其他硫化物是许多有害微量元素的重要载体。      

陕西渭北聚煤区原煤的微量元素组成特征

对陕西省渭北主要煤田主采煤层中的As、Pb、Hg、Cd、Se、Cu、Sr、Ba、B等微量元素的分析结果表明：渭北原煤中Hg、Se、As、Pb、B含量明显高于地壳平均值，呈富集状态；Co、Cd与地壳平均值接近，Cu、Zn、Sr、Ba等元素均亏损。太原组和山西组由于成煤环境不同，煤质和原煤的微量元素组成特征存在一定的差异。太原组煤的友分和硫分均较山西组煤高，原煤中As、Hg、Se、Pb、Zn、B的合量明显高于山西组原煤，而山西组原煤中V、Cr、Cu、Mn、Ba的含量别明显高于大原组原煤。统计分析表明，As、Hg、Se、Pb、Cu等亲硫元素与铁呈显著的正相关关系，它们的赋存形式可能与煤中黄铁矿有关。     

淮南张集矿区煤中微量元素的含量分布特征分析

在采用ICP-AES对张集7个煤层144个样品微量元素含量测试分析的基础上,探讨了元素在不同煤层中的变化规律及其在煤层对比中的应用。结果表明:张集矿区煤中元素B、Se和As含量偏高;不同煤层中微量元素含量变化较大,但具有一定的规律性,其中在9煤层中元素Ba和Cr含量最低,Mn、Zn、As和Se含量相对较高,可以利用这些元素分布特征来区别和划分相邻煤层。     

Geochemistry of environmentally sensitive trace elements in Permian coals from the Huainan coalfield, Anhui, China

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.     

河北开滦矿区煤洗选过程中 15种主要有害微量元素的迁移和分配特征

以河北开滦矿区晚古生代煤及其洗选产品为例,运用电感耦合等离子体质谱 (ICP-MS)和冷原子吸收光谱 (CV-AAS)方法对煤中主要微量有害元素 (包括 Be、 Cr、 Co、 Ni、 Cu、 Zn、 Ga、 As、 Se、 Mo、 Tl、 Pb、 Th、 U和 Hg)的含量及其在洗选过程中的迁移和分配特征进行了研究.通过对开滦矿区 10个矿井 47个煤层刻槽样品主要有害微量元素含量的统计,发现开滦矿区晚古生代煤中 Cr、 Ni、 Cu、 Zn、 Pb和 As富集.通过对原煤精煤中煤尾煤煤泥两套系列样品的分析,发现主要有害微量元素在精煤中都有不同程度的脱除,中煤中相对富集的元素有 Se和 Th,明显被脱除的元素有 Co和 Tl.除 Tl以外,尾煤中主要微量有害元素均有不同程度的富集,以 As的富集率最高,可达 34.4%, Hg的富集率最低,为 1.1%.煤泥中所有微量有害元素均相对富集,以 Hg的相对富集率最高,达 78.4%.因此,如果对尾煤和煤泥加以利用,需要特别关注 As和 Hg等微量有害元素对环境的影响.主要微量有害元素在洗选过程中的分配行为主要受控于它在煤中的赋存状态.     

A statistical approach to the study of the distribution of trace elements and their organic/ inorganic affinity in lower Gondwana coals of India

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.     

电感耦合等离子体发射光谱-逐级化学提取法研究低硫煤矸石中微量元素的赋存状态及其环境效应

煤矸石是我国堆存量最大的工业固体废物,本文应用电感耦合等离子体发射光谱法、逐级化学提取法和相关性分析研究了淮北临涣矿区低硫煤矸石中10种微量元素的含量及赋存状态,并运用风险评价指数法评价其环境效应。结果表明,低硫煤矸石中Ba、Co、Cr、Mn、Ni、Pb、V含量均高于淮北煤和中国煤均值,Mn、V的富集系数大于1,有一定迁移风险。微量元素主要以残渣态和铁锰氧化物结合态存在,两者质量分数之和为68.87%~92.93%,其中Cd、Co、Cr、Cu、Ni、Pb、Zn赋存于硫化物矿物中,V赋存于黏土矿物中,Mn赋存于碳酸盐矿物和硫化物矿物中。10种微量元素对环境的危害性大小为:MnZnNiPbCdCuBaVCrCo,表明低硫煤矸石堆存过程中活性态Mn对生态环境造成危害的可能性最大,由Mn可能引起的煤矸石山周边地区土壤及水体污染应当重视。     

晋北-宁北煤中痕量元素的地球化学特征

应用仪器中子活化 (INAA)、电感耦合等离子体原子发射光谱 (ICP- AES)和原子吸收光谱 (AAS)等方法测定了晋北-宁北一线 5对矿井、 2个露天矿、 5个电厂和 3个洗煤厂煤中环境敏感性痕量元素的含量;通过与中国土壤、其他地区煤以及世界范围煤中痕量元素含量进行对比,总结了研究区痕量元素的分布、富集特征,得知部分地区煤中 Hg、 Cd和 Se的含量较高,在燃烧利用过程中可能对环境造成影响.通过分析痕量元素与灰分、挥发分的相关性以及痕量元素间、痕量元素与 Al、 Fe和 Sp的相关、聚类特性,探讨了痕量元素间及其与矿物质间的亲合性及赋存特征.     

The origin and distribution of HAPs elements in relation to maceral composition of the A1 lignite bed (Paleocene, Calvert Bluff Formation, Wilcox Group), Calvert mine area, east-central Texas

The origin and distribution of twelve potentially Hazardous Air Pollutants (HAPs; As, Be, Cd, Cr, Co, Hg, Mn, Ni, Pb, Sb, Se, and U) identified in the 1990 Clean Air Act Amendments were examined in relation to the maceral composition of the A1 bed (Paleocene, Calvert Bluff Formation, Wilcox Group) of the Calvert mine in east-central Texas. The 3.2 m-thick A1 bed was divided into nine incremental channel samples (7 lignite samples and 2 shaley coal samples) on the basis of megascopic characteristics. Results indicate that As, Cd, Cr, Ni, Pb, Sb, and U are strongly correlated with ash yield and are enriched in the shaley coal samples. We infer that these elements are associated with inorganic constituents in the coal bed and may be derived from a penecontemporaneous stream channel located several kilometers southeast of the mining block. Of the HAPs elements studied, Mn and Hg are the most poorly correlated to ash yield. We infer an organic association for Mn; Hg may be associated with pyrite. The rest of the trace elements (Be, Co, and Se) are weakly correlated with ash yield. Further analytical work is necessary to determine the mode of occurrence for these elements. Overall, concentrations of the HAPs elements are generally similar to or less than those reported in previous studies of lignites of the Wilcox Group, east-central region, Texas. Petrographic analysis indicates the following ranges in composition for the seven lignite samples: liptinites (5–8%), huminites (88–95%), and inertinites (trace amounts to 7%). Samples from the middle portion of the A1 bed contain abundant crypto-eugelinite compared to the rest of the samples; this relationship suggests that the degradation of plant material was an important process during the development of the peat mire. With the exception of Hg and Mn, relatively low levels of the HAPs elements studied are found in the samples containing abundant crypto-eugelinite. We infer that the peat-forming environment for this portion of the coal bed was very wet with minimal detrital input. Relatively high concentrations of crypto-humotelinite were found in samples from the top and base of the coal bed. The presence of abundant crypto-humotefinite in this part of the coal bed suggests the accumulation of wood-rich peat under conditions conducive to a high degree of tissue preservation in the peat mire. Although several of the trace elements (Be, Co, Ni, and Sb) exhibit enrichment in these samples, they are not necessarily chemically associated with humotelinite. We infer that these elements, with the exception of Be, are possibly associated with deposition of the roof and floor rock of the coal bed; however, further analytical work would be necessary to confirm this hypothesis. Beryllium may have an organic origin.     

Abundances and modes of occurrence of trace elements in the Çan coals (Miocene), Çanakkale-Turkey

This study presents the concentrations and modes of occurrence of trace elements in 81 coal samples from the Çan basin of northwestern Turkey. The concentration of trace elements in coal were determined by inductively coupled plasma-mass spectrometry and inductively coupled plasma-atomic emission spectrometry. Additionally, traditional coal parameters were studied by proximate, ultimate, X-ray diffraction, and petrographic analyses. Twenty trace elements, including As, B, Ba, Be, Cd, Cu, Co, F, Hg, Mo, Ni, Pb, Sb, Se Sn, Th, Tl, U, V, and Zn, receive much attention due to their related environmental and human health concerns. The Çan coals investigated in this study are lignite to sub-bituminous coal, with a broad range of ash yields and sulphur contents. The trace element concentrations show variety within the coal seams in the basin, and the affinities vary among locations. The concentrations of B, Ba, Be, Cd, Cu, Co, F, Hg, Mo, Ni, Pb, Sb, Se, Sn, Tl, and Zn in Çan coals are within the Swaine's worldwide concentration range, with the exception of As, Th, U, and V. On the other hand, compared with world coals, the Çan basin coals have higher contents of As, B, Cu, Co, Mo, Pb, Th, U, V, and Zn. Based on statistical analyses, most of the trace elements, except for U, show an affinity to ash yield. Elements including As, Cd, Hg, Se, Cu, Mo, Ni, and Zn, show a possible association with pyrite; however, the elements Se, B, and Mo can be have both organic and inorganic associations.     

吉南地区不同沉积环境原煤微量元素地球化学特征

对吉林南部地区煤矿主采煤层中的As、B、Ba、Cd、Cu、Hg、Pb、Se、Sr等微量元素的分析结果表明，太原组与山西组由于成煤环境不同，微量元素组成及含量存在一定的差异：太原组原煤中As、B、Hg、Pb、Se、Zn的含量明显高于山西组，山西组原煤中Ba、Cr、Cu、Mn、V的含量明显高于太原组。吉南煤区原煤中As、B、Hg、Pb、Se明显高于地壳元素平均值，呈富集状态，Co、Cd与地壳平均值接近，其他元素均亏损。与全国煤中微量元素相比，该区原煤中As、Ba、Co、Cr、Cu、Hg、Ni、Pb、Se、V、Zn的含量高于全国平均值，B、Mn、Sr含量低于全国平均值。微量元素赋存状态及相关分析表明，Fe与亲硫有害元素As、Cu、Hg、Pb、Se具有显著相关关系，说明煤中黄铁矿及其他硫化物是许多有害微量元素的重要载体。     

电感耦合等离子体质谱-原子荧光光谱法研究上海口岸进口印度尼西亚煤炭微量元素的赋存形态特征

印度尼西亚是我国最大的煤炭进口国,本文应用电感耦合等离子体质谱、原子荧光光谱、直接测汞仪等技术分析了上海口岸31批进口印度尼西亚煤炭中的12种微量元素,结合数理统计方法研究该类煤炭中微量元素的赋存形态。结果表明,进口印尼煤炭中含有高汞煤、三级含砷煤,As、Hg的平均富集系数大于1,其迁移风险值得关注;Be、Cu、Mo、Cd、Sn、Pb含量均低于中国煤和世界煤炭的平均水平,体现出印尼煤炭低灰分的品质特征。12种微量元素和相关项目(灰分和全硫)可划分为3类:第一类归纳为黏土矿物吸附类,包括As、Be、Cr、Co、Ni、Cu、Mo、Cd、Sn、Pb、灰分;第二类归纳为硫铁矿类,包括Hg、全硫;第三类归纳为碳酸盐矿物类,包括Ba。本文研究结果对于指导进口煤炭开发、利用过程中的环境评价和洁净化处理具有一定的参考价值。     

Geochemistry and Modes of Occurrence of Hazardous Trace Elements in the No. 11 Coal Seam, Antaibao Surface Mine, Shanxi Province

Concentrations of seventeen hazardous trace elements including As, Pb, Hg, Se, Cd, Cr, Co, Mo, Mn, Ni, U, V, Th, Be, Sb, Br and Zn in the No.ll coal seam, Antaibao surface mine, Shanxi Province were determined using Instrumental Neutron Activation Analysis （INAA）, Inductively Coupled Plasma Atomic Emission Spectrometry （ICP-AES）, Cold-Vapor Atomic Absorption Spectrometry （CV-AAS） and Graphite Furnace Atomic Absorption Spectrometry （GF-AAS）. Comparisons with average concentrations of trace elements in Chinese coal show that the concentrations of Hg and Cd in the No. 11 coal seam, Antaibao surface mine are much higher. They may be harmful to the environment in the process of utilization. The variations of the trace elements contents and pyritic suffur in vertical section indicated that： （a） the concentrations of As, Pb, Mn, and pyritic sulfur decrease from roof to floor; （b） the concentrations of Cr, Zn and Mo are higher in roof, floor and lower in coal seam; （c） the concentration of Br, Sb, and Hg are higher in coal seam and lower in roof and floor; （d） the concentrations of Mo, V, Th and AI vary consistently with the ash yield. Cluster analysis of trace elements, pyritic sulfur, ash yield and major elements, such as AI, Fe, P, Ca shows that： （a） pyritic sulfur, Fe, As, Mn, Ni, Be are closely associated and reflect the influence of pyrite; （b） Mo, Se, Pb, Cr, Th, Co, Ca and A! are related to clay mineral, which is the main source of ash; （c） U, Zn, V, Na, P maybe controlled by phosphate or halite; （d） Hg, Br, Sb and Cd may be mainly organic-associated elements which fall outside the three main groups. The concentration distribution characteristics of trace elements in coal seam and the cluster analysis of major and trace elements showed that the contents of trace elements in the No. 11 coal seam, Antaibao surface mine, are mainly controlled by detrital input and migration from roof and floor.     

Concentration and distribution of elements in Late Permian coals from western Guizhou Province,China

With the aim of better understanding geochemistry of coal, 71 Late Permian whole-seam coal channel samples from western Guizhou Province, Southwest China were studied and 57 elements in them were determined. The contents of Al, Ca, Co, Cr, Cu, Fe, Ga, Hf, K, Li, Mn, Mo, Nb, Ni, Sn, Ta, Ti, Th, U, V, Zr, and REEs in the Late Permian coals from western Guizhou Province are higher than the arithmetic means for the corresponding elements in the US coals, whereas As, Ba, Br, F, Hg, P, Se, and Tl are lower. Compared to common Chinese coals, the contents of Co, Cr, Cu, Ga, Hf, Li, Mn, Mo, Ni, Sc, Sn, Ti, U, V, Zn, and Zr in western Guizhou coals are higher, and As, F, Hg, Rb, Sb, Tl, and W are lower. Five groups of elements may be classified according to their mode of occurrence in coal: The first two, Group A, Tm–Yb–Lu–Y–Er–Ho–Dy–Tb–Ce–La–Nd–Pr–Gd–Sm, and Group B, As–Sr–K–Rb–Ba–F–Ash–Si–Sn–Ga–Hf–Al–Ta–Zr–Be–Th–Na, have high positive correlation coefficients with ash yield and they show mainly inorganic affinity. Some elements from Group B, such as Ba, Be, Ga, Hf, and Th, are also characterized by significant aluminosilicate affinity. In addition, arsenic also exhibits high sulfide affinity (r_S–Fe>0.5). The elements, which have negative or lower positive correlation coefficients with ash yield (with exceptions of Bi, Cs, Nb, Mn, Se, and Ti), are grouped in other four associations: Group C, Cr–V–Mo–U–Cd–Tl; Group D, Hg–Li–Sc–Ti–Eu–Nb–Cs–W; Group E, Bi–Sb; and Group F, Co–Ni–Cu–Pb–Zn–Mg–Se–Ca–Mn–S–Fe. The correlation coefficients of some elements, including Co, Cr, Cu, Fe, Hg, Li, Mo, Ni, P, S, Sc, U, V, and Zn, with ash yield are below the statistically significant value. Only Cr and Cu are negatively correlated to ash yield (−0.07 and −0.01, respectively), showing intermediate (organic and inorganic) affinity. Manganese and Fe are characterized by carbonate affinity probably due to high content of epigenetic veined ankerite in some coals. Phosphorus has low correlation coefficients with any other elements and is not included in these six associations. There are five possible genetic types of enrichment of elements in coal from western Guizhou Province: source rock, volcanic ash, low-temperature hydrothermal fluid, groundwater, and magmatic hydrothermal inputs.     

Trace elements in high-S subbituminous coals from the teruel Mining District, northeast Spain

The elemental composition of high temperature ash (750°C) and forms of S were studied in 25 coal seams from the Escucha Formation (Middle Albian) in the Teruel Mining District, northeast Spain. The principal analytical method was ICP-MS, but ICP-ES was also used in the determination of some trace elements. The analytical data show wide ranges of trace element cotnents among the coal seams studied, even in the vertical profile of a single coal seam. These wide ranges of the trace element concentrations are attributed to both syngenetic and epigenetic processes.When a comparison was made between the average trace element contents of the Teruel Mining District coals, and those of the average content in worldwide coals, the Teruel coals show slightly higher concentrations of Be and U, and lower concentrations of Ba, Cd, Mn, Pb, Sr and Zr. Further, three main groups of trace elements were differentiated on the basis of the inorganic/organic association: (1) trace elements with inorganic affinity; Ba, Ce, Co, Cr, La, Mn, Ni, Rb and Zr. Between these, Ba, Ce, Cr and Rb show a well defined correlation with the clay mineral content, and Co and Ni with pyritic-S content; (2) trace elements with an intermediate (mixed) affinity; As, Cd, Cu, Dy, Er, Eu, Gd, Ge, Ho, Lu, Mo, Nd, Pb, Pr, Sb, Sm, Sr, Tb, Th, Tm, U, Yb and Zn. In this group, As, Cd, Cu, Ge, Mo, Th, U and Zn show a weak trend associated with the mineral matter and Sr with the organic matter; and (3) Be shows an organic affinity. The high mineral matter content (21.3% HTA) of the Teruel coals may account for the great number of elements with inorganic affinity. This classification represents a general trend, but the results show that the affinities of some trace elements (e.g. As, Sb and Zn) may vary from one coal seam to another in the Teruel Mining District.     

Distribution Characteristics of Sulfur and the Main Harmful Trace Elements in China's Coal

To promote the rational development and use of clean coal resources in China,data on the regional and age distribution of sulfur,arsenic and other harmful elements in Chinese coal was broadly collected,tested for content,and analyzed.Coal in northwestern China is characterized by low to extremely low levels of sulfur;the coal of the Taiyuan Formation in northern China mainly has high-sulfur content;that of the Shanxi Formation is mainly characterized by low sulfur coal;and the Late Permian coal in southern China has overall higher sulfur content;other regions have low sulfur coal.The average content of harmful trace elements in the bulk of China's coal is similar to the corresponding content in the coal of the North America and the rest of the world,whereas the content of various elements(Hg,Sb and Se)is different in magnitude to the corresponding percentage in the crust.The average content of the elements Cr,Se,Co,Be,U,Br in Late Permian coal in S China ranks first in the country whereas the average content of Hg and Cl in the coals of Late Carboniferous to Early Permian age in N China are the highest.The average content of Mn in Early and Middle Jurassic coal is higher in NW China.The high content of harmful elements in some coal should cause particular concern both in the development and utilization of coal.     

淮南煤田深部A组煤中有害微量元素地球化学特征

以淮南煤田深部A 组煤为研究对象,全层刻槽采集了煤、夹矸和顶底板岩石样品,采用电感耦合等离子质谱仪 （ICP-MS） 测试分析了样品中13 种有害微量元素的含量,对比研究了其分布特征,结合Tessier 五步形态提取法和相关性分 析探讨了煤中有害微量元素的赋存形态。结果表明：（1） 与中国上陆壳中各种微量元素含量均值相比,淮南深部A 组煤中 B,As,Se,Mo,Cd,Pb,Hg 的富集系数均大于1,在A 组煤中表现为富集;A 组煤中B,As,Se,Cd 的含量均高于淮南煤 田上部B 组煤、华北煤以及中国煤中的含量均值;（2） 相关性分析和逐级提取实验结果表明,A 组煤中微量元素主要以残 渣态和铁锰氧化物结合态存在,两者质量分数之和达到55%~98%,其中Ni,Mo,Cd,Hg,Cu,Pb 和Zn 主要赋存于硫化物 矿物中,Mn 主要赋存于碳酸盐矿物中,V,Cr,Se,B 和As 主要赋存于硅铝酸盐等黏土矿物中。（3） B 元素示踪物源及沉 积环境结果显示,淮南煤田深部A 组煤成煤环境为海相咸水沉积环境,稳定的咸水沉积环境以及受海水影响等因素导致A 组煤中微量元素出现不同程度的富集。     

辽宁北票地区煤中微量元素研究

对辽宁北票地区煤中微量元素进行了研究 ,将研究区煤中微量元素的平均质量分数与世界范围煤的微量元素的平均质量分数进行比较 ,发现北票煤中的Cr、Co、Ni、As、Sr、Y、Zr、Ba、Ta、Sc具有较高的富集 ,而Sn、U具有较低的富集 ,这种差异可能主要与聚煤区域的地球化学背景有关。计算了微量元素之间的相关系数 ,得出北票地区煤中稀土元素总量较世界范围稀土元素总量的平均值偏高 ,且煤中稀土元素分布模式十分相似 ,表明在成煤期间陆源物质供应相对稳定。煤中矿物主要为高岭石、石英及方解石及少量的伊利石 ,并对其中的地质成因进行了初步解释。