Phase–mineral and chemical composition of composite samples from feed coals,bottom ashes and fly ashes at the Soma power station,Turkey

The phase–mineral and chemical composition of feed coals (FCs) and their bottom ashes (BAs) and fly ashes (FAs) produced in the Soma thermo-electric power station (TPS), Turkey, was characterized. FCs are high-ash Soma subbituminous coals abundant in moisture and Ca, and depleted in S. The inorganic composition (in decreasing order of significance) of FCs includes calcite, quartz, kaolinite, illite+muscovite, chlorite, plagioclase, gypsum, pyrite, montmorillonite, K-feldspar, dolomite, siderite, ankerite, opal, and volcanic glass. The results for 57 elements studied show that Ca>Nb>Cs>(V, Li) have significantly higher contents in FC ashes than the respective Clarke values for coal ashes. The water-soluble residues isolated from FCs include gypsum, calcite, inorganic amorphous matter, Ca–Mg–Na–K phase, and opal. These residues are enriched in Na>Se>S>B>Mg>Mo>Sr>Ca>K. The phase–mineral composition of BAs and FAs includes mainly glass, quartz, char, mullite, plagioclase, calcite, and portlandite; and, to a lesser extent, illite+muscovite, melilite, hematite, anhydrite, lime, cristobalite, kaolinite, and magnetite. Minor amounts of K-feldspar, dolomite, ankerite, Fe-spinel, gypsum, and Ca–K–Na phase also occur in BAs and FAs. FAs are enriched in inorganic matter, glass, cristobalite, mullite, Fe oxides, lime, and anhydrite, and depleted in mineral matter, char, quartz, clay minerals, melilite, portlandite, and carbonates in comparison with BAs. Only Se is significantly enriched in BAs and FAs compared to FC ashes. Most of the trace elements (in particular As, Bi, Cd, Ge, Pb, Sn, Tl, and W) are more abundant in FAs, while BAs are more enriched in Ca, Cs, Fe, Ho, Mn, P, Sc, Se and Tb. Significant percentages (11–59%) of elements initially present in FCs, namely S>Sb>Sn>Ta>Mo>Bi>Zn>Ni>Na>(Lu, Tm)>B, were emitted by stack emissions and not captured by the cleaning equipment in the Soma TPS. Some genetic features, properties, possible environmental concerns, and potential utilization directions related to FCs, BAs, and FAs are also discussed.     

Geochemistry of Permian Coal and Its Combustion Residues in Huainan Coalfield, China

INTRODUCTIONMany environmental problems may arise during coal min-ing and utilization. Among these prob1ems, much attention hasbeen paid to S(), and NO. emission during coal combustion.But the environmental effects produced by hazardous elementsduring coal mining and utilization are also important and de-serve to be studied (Goodazi, 1995; Finkelman, 1993; Valk-ovic, l983). For example, when coal wastes are used for landreclamation, the harmful elements in them may pollute water,soil an…     

Mineralogical speciation of elements in an eastern Canadian feed coal and their combustion residues from a Canadian power plant

Systematic changes in mineralogy, enrichment and depletion of selected elements, and mineralogical speciation of selected elements in fly ash and bottom ash samples from the Lingan Power Plant were compared to run-of-mine and pulverized feed coal from the Sydney coalfield, Nova Scotia, eastern Canada. The analytical techniques used were an electron microprobe equipped with energy and wavelength X-ray dispersive spectrometers, X-ray diffraction, neutron activation, scanning electron microscopy with energy dispersive X-ray and incident light petrography. Three types of glasses (Fe/O-rich, Fe/Al/Si/O-rich and or Al/Si/O-rich) were identified in the combustion residues; they were formed as a result of the interaction of melted pyrite and clay minerals. Compared to the feed coal, most elements were enriched 10 to20 times in the fly ash. The concentration of the elements in both the fly ash and bottom ash are comparable to coal ash that is generated by the low temperature asher in the laboratory. Some chalcophile elements such as arsenic and lead occurred as a solid solution in pyrite in the feed coal and were concentrated in the float fraction (density: <2.81 g/cm³) of the fly ash with non-crystalline Fe-oxides. X-ray mapping of arsenic in the fly ash and bottom ash indicates that arsenic was evenly distributed as oxide within the Fe/O- and Fe/Al/Si/O-rich glass and crystalline phases in the fly ash, possibly in solid solution. Arsenic is associated with Fe/O and Fe/S crystalline phases in the bottom ash.     

Chemical and petrographical characterization of feed coal, fly ash and bottom ash from the Figueira Power Plant, Paraná, Brazil

The aim of the present study is the petrographic and chemical characterization of the coal at the Figueira Power Plant, Paraná, Brazil, prior and after the beneficiation process and the chemical characterization of fly and bottom ashes generated in the combustion process.Petrographic characterization was carried out through maceral analysis and vitrinite reflectance measurements. Chemical characterization included proximate analysis, determination of calorific value and sulphur content, ultimate analysis, X-ray diffraction, X-ray fluorescence, Inductively Coupled Plasma — Mass Spectrometry (ICP-MS) and Inductively Coupled Plasma — Atomic Emission Spectrometry (ICP-AES) analysis, and determination of Total Organic Carbon (TOC) content.Vitrinite reflectance analyses indicate a high volatile B/C bituminous coal (0.61 to 0.73% Rrandom). Maceral analyses show predominance of the vitrinite maceral group (51.6 to 70.9 vol.%, m.m.f). Except of the Run of mine (ROM) coal sample, the average calorific value of the coals is 5205 kcal/kg and ash yields range from 21.4 to 38.1 wt.%. The mineralogical composition (X-ray diffraction) of coals includes kaolinite, quartz, plagioclase and pyrite, whereas fly and bottom ashes are composed by mullite, ettringite, quartz, magnetite, and hematite. Analyses of major elements from coal, fly and bottom ashes indicate a high SiO₂, Al₂O₃, and Fe₂O₃ content. Trace elements analysis of in-situ and ROM coals by ICP-MS and ICP-AES show highest concentration in Zn and As. Most of the toxic elements such as As, Cd, Cr, Mo, Ni, Pb, and Zn are significantly reduced by coal beneficiation. Considering the spatial distribution of trace elements in the beneficiated coal samples, which were collected over a period of three months, there appears to be little variation in Cd and Zn concentrations, whereas trace elements such as As, Mo, and Pb show a larger variation.In the fly and bottom ashes, the highest concentrations of trace elements were determined for Zn and As. When compared with trace element concentrations in the feed coal, fly ashes show a significant enrichment in most trace elements (As, B, Be, Cd, Co, Cr, Cu, Li, Mn, Mo, Ni, Pb, Sb, Tl, and Zn), suggesting a predominantly volatile nature for these elements. In contrast, Sn is distributed evenly within the different ash types, whereas U shows depleted concentration in both bottom and fly ash samples.According to the International Classification of in-seam coals the Cambuí coals are of para/ortho bituminous rank of low grade (except for the ROM sample), and are characterized by the predominance of vitrinite macerals.     

淮南二叠纪煤及其燃烧产物地球化学特征

采用仪器中子活化分析法INAA（instrumental neutron activation analysis)测试了淮南煤田二叠纪主采煤层原煤煤样的地球化学组成，用X－射线荧光光谱XRFS（X－ray fluorescence spectrometry)测试了田家庵和洛河电厂的粉煤灰地球化学组成并与煤样作了对比分析，用电子探针测试了飞灰中主要类型颗粒的化学组成，淮南煤中多数微量元素属正常水平，与克拉克值相比，元素Se,S,As,Sb,Br,U和Cl等在煤中趋于富集，其他元素均趋于分散，有机亲和性弱的亲石元素趋于在粉煤灰中聚集，与铁关系密切的金属元素在粉煤灰中有明显的富集，有机亲合性强的元素在燃烧过程中趋于以气态形式向空气中逸散，粉煤灰中因矿物与粒度的分异明显，致使其化学组成在不同的粒度级和比重级中的分布也有较大的不同，飞灰中一些不定形颗粒主要由铁的氧化物和少量其他金属氧化物组成，硅酸盐类颗粒主要由硅，铝和铁的氧化物所组成，而玻璃珠主要由硅和铝的氧化物组成，残碳中测得的砷，硫和氯的含量最高，说明其对这些元素具有较强的吸附能力，研究粉煤灰的成分特点有助于粉煤灰的综合利用和评价其对环境的 影响。     

燃煤固体产物的矿物组成研究

利用X射线衍射、穆斯堡尔谱与扫描电子显微镜等方法研究中国典型燃煤煤种的燃烧产物的矿物学特征，揭示出不同化学成分以及不同类型产物中矿物组成的差异性。根据化学成分，可将燃煤固体产物分为硅铝质、铁质和钙质三组，硅铝质产物结晶相主要为莫来石和石英，而结渣中基本为莫来石；铁质产物中主要矿物包括α-Fe2O3、γ-Fe2O3与Fe3O4，其含量随锅炉燃烧湿度的变化而变化；钙质产物中矿物种类复杂，飞灰石检出石灰、石膏和石英，沾污中检出石膏、赤铁矿和石类，而结渣中还发现钙的硅酸盐矿物。上述矿物分布特征是由不同成分的硅酸盐熔体在不同热力学条件下的结晶行为所决定的。     

Purification of the Beonite from Shangtianti,Henan Province,China

Bentonites consisting mainly of montmorillonite are widely utilized in various applications. However, natural bentonites contain many kinds of impurities such as quartz, cristobalite, feldspar, zeolite, calcite etc., which can decrease the performance of bentonite. Furthermore, quartz and cristobalite are carcinogenic. Therefore purification of bentonite is critical to its applications. Among the impurities in bentonite, cristobalite is the most difficult one to get rid of because of its tiny particle size and aggregation state.     

鸡西煤的无机地球化学研究

鸡西煤田是东北地区重要的炼焦煤基地，由于受成煤环境的影响，原煤灰分较高，影响了煤炭精细加工利用和环境。采用Ｘ射线衍射、红外光谱等分析方法对鸡西煤的无机地球化学特征研究显示，煤中的主要矿物为石英、方解石、粘土矿物、黄铁矿和菱铁矿等，它们分别以不同的状态赋存于有机质中。煤灰的主要成分为ＳｉＯ２和Ａｌ２Ｏ３，其主要源自流水带入泥炭沼泽的石英和粘土等同生矿物。元素分析表明，煤中硫、磷及微量元素锗和镓等含量较低。     

黄骅坳陷三马地区中-深部储层成岩作用及主控因素分析

黄骅坳陷三马地区储集岩样品的显微特征及成岩矿物的组合关系分析结果表明，三马地区下第三系中深层储层主要处于晚成岩A期，成岩现象包括石英、长石的次生加大、碳酸盐矿物胶结作用、矿物交代作用、溶解作用和粘土矿物转化作用等。其中石英次生加大于2700m左右开始出现，随埋深增大，石英增生加强；长石次生加大现象不十分普遍；碳酸盐胶结作用包括早期自生泥晶方解石胶结作用、连晶方解石和晚期白云石(或铁方解石)的胶结作用。在扫描电镜下可见到方解石与含铁方解石集合体充填在粒间孔隙中或与石英、钠长石及粘土矿物共生，白云岩多呈菱形粒状分布于粒间；常见的交代现象主要有方解石交代长石、石英及粘土矿物，粘土矿物交代长石、石英等；溶解作用主要有长石的溶解、碳酸盐颗粒的溶解和方解石胶结物的溶解等，粘土矿物的转化主要为蒙脱石、高岭石向伊利石(或绿泥石)转化。还讨论了储层岩相、岩性特征、孔隙水中有机酸含量、早期方解石的充填、烃类早期注入等因素对储层成岩演化的控制作用。     

煤及其燃烧产物飞灰和底灰中稀土元素地球化学特征及集散规律

采用ICP—MS法测试了褐煤、肥煤和无烟煤以及在不同燃烧条件下获取的飞灰、底灰等29个样品的稀土元素含量;分析了稀土元素地球化学特征。结果表明,不同煤种的稀土元素含量不同,相同煤种在不同燃烧条件下获取的飞灰、底灰中的稀土元素含量也不同;褐煤、肥煤、无烟煤及其燃煤产物飞灰、底灰的稀土元素分布模式呈左高右低的宽缓的“V”型曲线;Eu存在明显负异常。研究了燃煤过程中稀土元素的分布及集散规律,稀土元素在飞灰、底灰中的含量比原煤有明显提高,其增加幅度为几倍至20多倍不等,表明煤炭燃烧后稀土元素在飞灰、底灰中进一步聚集;飞灰和底灰中稀土元素含量、飞灰和底灰对煤的稀土元素含量比和富集因子以及飞灰对底灰的稀土元素含量比和富集因子等,不仅与原煤中稀土元素有直接关系,而且还受锅炉燃烧方式、燃烧温度(炉温)等人为因素的影响。     

Depositional conditions of the coal-bearing Hirka Formation beneath Late Miocene explosive volcanic products in NW central Anatolia,Turkey

This work focuses on the relationship between the coal deposition and explosive volcanism of the Miocene basin, NW central Anatolia, Turkey. The coal-bearing Hirka Formation was deposited over the Galatian Andesitic Complex and/or massive lagoonal environments during the Miocene. The investigated lignite is a high ash (from 32 to 58%) and sulphur (from 1.43 to 3.03%) lignite which is petrographically characterised by a high humunite content. The mineral matter of the studied lignite samples is made up of mainly clay minerals (illite-smectite and kaolinite), plagioclase and quartz in Bolu coal field, clay minerals (illite-smectite, smectite and illite), quartz, calcite, plagioclase and gypsum in Seben coal field, quartz, K-feldspar, plagioclase and clay minerals (kaolinite and illite) in K?br?sc?k, and dolomite, quartz, clinoptilolite, opal CT and gypsum in Çaml?dere coal field. The differences in these four types of lignite with specific mineralogical patterns may be due to the explosive volcanic events and depositional conditions which changed from one coal field to the others. There is a zonation from SW to SE in the studied area for zeolites such as Opal CT+smectite-clinoptilolite-analcime-K-feldspar. Carbonate minerals are commonly calcite in Seben and K?br?sc?k coal fields. In Bolu, coal samples are devoid of calcite and dolomite. These analyses show that there is an increase in the amount of Mg and a decrease in the amount of Na from the northwestern part to the southern part in the study area.     

Occurrence, distribution and probable source of the trace elements in ghugus coals, wardha valley, districts chandrapur and yeotmal, maharashtra, India

Trace-element determinations of 15 coal samples have been made in order to know their distribution, behaviour and associations with the organic and inorganic fractions in the coal. The coal samples have been systematically collected in stratigraphic sequences so that the vertical variation of the trace-elements can be studied. The elements determined by spectographic analysis are W, V, Cr, Sc, Y, Cu, Co, Pb, Be, Ni and Ba. The results indicate that the concentration of trace elements in these coals varies greatly from bottom to top sections. The elements V and Co are extremely poor in the top and middle sections, whereas in the bottom section they are fairly distributed. Be is extremely poor in the bottom section, and fairly distributed in the middle and top sections. W, Sc, Y have poor concentration in the bottom section as compared to the middle and top sections. Ni is fairly distributed in the bottom section whereas its concentration is poor in the middle and top sections. Cr and Cu are fairly distributed in the bottom, middle and top sections. Ba has unusually high concentration in all the sections.It appears from the present study that W, Cr, Sc, Y and Be are concentrated more in silicate minerals (clay, quartz, etc.) associated with coal, and the elements like , Co, and Ni have intimate relation with organic matters in coal and are present as organometallic compounds as well as absorbed cations. Cu and Pb which are present in the coals are derived from the inorganic matter, mainly from the pyrites, whereas W has affinity with carbonate minerals in the coals. The Ba is mainly associated with the inoraanic matter of coal; its unusually high concentration indicates association with carbonates, clays and other silicate minerals.     

内蒙古潮水盆地西部侏罗系煤的岩石学、矿物学及地球化学特征

潮水盆地位于内蒙古西南部和甘肃省东部地区,是我国中新生代含煤断陷盆地.采用粉晶X衍射、ICP-MS、ICP-AES 方法,从煤的岩石学、煤化学及煤地球化学的理论出发,对潮水盆地西部煤样进行了煤化学、显微组分、矿物学及地球化学分析.其研究结果表明潮水盆地西部煤以中等水分、低一中灰分和硫质量分数、高挥发分产率为特征,煤级为烟煤—亚烟煤;煤中有机显微组分以镜质组为主,惰性组次之,煤相类型以潮湿森林沼泽相为主,其次为较浅覆水森林沼泽相;煤中的常量矿物以石英和高岭石为主,部分样品中含有黄铁矿、方解石、菱铁矿和少量的微斜长石;煤中除Sr、B和Cs质量分数相对较高外,其他微量元素质量分数普遍较低.Cr、Ga、Pb、Li、Cu、Ge、V、Sc、Be、W、Th和As,以及Ti和Nb主要与硅铝酸盐矿物有好的亲和性;B和Sr可能主要以碳酸盐矿物的形式存在;S和Mo可能主要以硫化物矿物的形式存在;另外,Ti、Zr、Nb和Ta有好的相关性,可能与重矿物有关.     

云南大关新地2井奥陶—志留纪之交钾质斑脱岩岩石地球化学特征分析

扬子地台内晚奥陶世末—早志留世初五峰—龙马溪组内沉积了多层钾质斑脱岩,但对于该时期扬子地台西缘钾质斑脱岩的研究报道相对较少.本文旨在通过对云南大关地区新地2井五峰—龙马溪组内沉积的钾质斑脱岩进行矿物学及地球化学分析,进一步确定扬子西缘该时期钾质斑脱岩原始岩浆类型及其所产生的构造环境.矿物学特征表明,钾质斑脱岩主要由黏土...     

From in-situ coal to fly ash: a study of coal mines and power plants from Indiana

This paper presents data on the properties of coal and fly ash from two coal mines and two power plants that burn single-source coal from two mines in Indiana. One mine is in the low-sulfur (<1%) Danville Coal Member of the Dugger Formation (Pennsylvanian) and the other mines the high-sulfur (>5%) Springfield Coal Member of the Petersburg Formation (Pennsylvanian). Both seams have comparable ash contents (11%). Coals sampled at the mines (both raw and washed fractions) were analyzed for proximate/ultimate/sulfur forms/heating value, major oxides, trace elements and petrographic composition. The properties of fly ash from these coals reflect the properties of the feed coal, as well as local combustion and post-combustion conditions. Sulfur and spinel content, and As, Pb and Zn concentrations of the fly ash are the parameters that most closely reflect the properties of the source coal.     

Radioelemental study of Kolaghat,thermal power plant,West Bengal,India: possible environmental hazards.

Coal combustion in power plants in India produces large quantities of coal-related wastes, e.g. fly ash and bottom ash. Indian coals used in power stations are of high ash content, thus resulting in the generation of large amounts of fly ash (~100 million tons/year). Combustion of coal results in enhanced concentration of most radionuclides found in waste materials. In the present work, an attempt has been made to assess the radiological impact of the Kolaghat thermal power plant in West Bengal, India. The fly ashes and coal from the power plant were analysed for ²³⁸U, ²³²Th and ⁴⁰K by a NaI (Tl)-based gamma-ray spectrometer. The results show that ²²⁶Ra and ²³²Th range from 81.9-126 and 132-169 Bq/kg in fly ash and 25-50 and 39-55 Bq/kg in coal. These results are high compared to those of other thermal power plants of India. Hence, the Kolaghat fly ash has a significant amount of radioactivity which, if not properly disposed, will be a serious threat to the ambient environment.     

Potential environmental pollution hazards by coal based power plant at Jhansi (UP) India

Coal, a fossil fuel, is the largest source of energy for the generation of electricity in India. In order to study the potential environmental hazards by coal based power plants, particulate matters were collected using Stack Monitoring Kit and gaseous pollutants by Automatic Flue Gas Analyzer. The morphological and chemical properties, mineralogical composition and particle size distributions have been determined by SEM–EDX, XRD and CILAS. The data revealed the presence of particulate matters, SO₂, NOx in the range of 236–315, 162–238, 173–222 mg/Nm³ respectively. The emission of CO₂ was in the range of 43,004–60,115 Nm³/h with an average of 52,830 Nm³/h. Among the elements, Fe > Mn > Al > Zn > B > Ni > Cr > Cu were present in substantially higher proportion than Pb > Mo > Cd > Se > As > Hg. It was found that most of the elements were concentrated on fly ash surface rather than coal, bottom ash and pond ash. This variation may be attributed to the fineness of fly ash particles with large surface ratio to mass. Mineralogical studies of coal and fly ash by X-ray diffraction revealed the presence of mullite, quartz, cristobalite and maghemite. Presence of mullite and quartz found in fly ash indicate the conversion of complex minerals to mullite and quartz at high temperature. Transfer Coefficient was calculated to determine the ratio of the enrichment of trace elements in fly or bottom ash with respect to coal and pond ash.     

陕西省华阳川铀铌铅矿床碳酸岩岩石学及地球化学特征

陕西省华阳川铀铌铅矿床是小秦岭成矿带中成矿特征最为独特的矿床,碳酸岩脉的破碎带是重要的成矿空间。未矿化的碳酸岩中矿物以方解石为主,其他矿物很少;发育铀矿化的碳酸岩脉中矿物种类繁多,大部分为方解石,其次为角闪石、金云母、榍石、褐帘石、铌钛铀矿、重晶石、磷灰石、石英、磁铁矿、碱性长石等矿物。碳酸岩的LREE含量异常高,δ13CV-PDB和δ18OV-SMOW值显示典型的火成碳酸岩特征。基于碳酸岩脉的Sr、Nd、Pb同位素比值(87Sr/86Sr-206Pb/204Pb、207Pb/204Pb-206Pb/204Pb-143Nd/144Nd-87Sr/86Sr)的关系图,初步判断华阳川铀铌铅碳酸岩脉是源于EMI的碱性硅酸盐-碳酸盐熔体-溶液结晶分异的产物。     

国产香烟矿物组成的初步研究

利用X射线衍射仪对28种国产香烟烟灰及其中的两种香烟(绿南京和云烟)的卷烟纸灰烬、烟丝以及过滤嘴中的矿物成分进行了研究.初步研究结果表明,香烟烟丝中含有一水草酸钙石,过滤嘴中不含任何矿物,烟灰中的矿物主要是方解石,此外还含有少量石英、钾盐、钾矾、石膏等矿物.这些矿物具有不同的来源:方解石来自卷烟纸,一水草酸钙石是烟叶生长期间自身合成的矿物,石膏是香烟燃烧过程中新形成的矿物.这些研究结果有可能为全面认识香烟致病机理提供一定的科学依据.