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《矿物岩石》2016,(3)
通过X射线荧光光谱仪、X射线衍射仪、场发射扫描电子显微镜、激光拉曼光谱仪、Zeta电位分析仪等表征手段,对湖南郴州不同矿区微晶石墨样品的成分、结构及物理性质进行研究。结果表明:微晶石墨样品由石墨和少量的绿泥石、石英、方解石、白云母组成,主要的化学元素为C,O,Si,Al,Fe,Ca等;微晶石墨颗粒多为细小的片状石墨集合体,固定碳含量为77.40%~86.39%;晶体结构均以2H型为主,同时含有14.99%~21.63%的3R型结构,石墨化度为0.59~0.80,与晶质石墨的晶体结构存在一定差距;微晶石墨表面在pH为5~13的水溶液中荷负电,当pH=12时,带电量最大,此时石墨颗粒在水溶液中有较好的稳定性,亲水性较强;微晶石墨样品的电阻率为17.7mΩ·cm~37.2mΩ·cm,并随石墨结构无序度R的增加而增大。本研究结果为该地区微晶石墨的开发与利用提供了重要参考依据。 相似文献
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利用SEM,XRD,Raman和XPS等手段分析了体积比为3：1的浓硫酸和浓硝酸的混合溶液对碳纳米管氧化前后的结构、形貌及表面特性。结果表明,混合强酸氧化后的碳纳米管变短、松散、端部开口、杂质减少;氧化后碳纳米管结构未受到严重破坏,但碳纳米管缺陷程度有所增加、有序度下降;氧化前后的碳纳米管表面均有一定量的—COH,—C=O和—COOH含氧基团,但酸化后的碳纳米管表面氧含量增加,且主要体现在—COOH基团量的增加上。 相似文献
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《吉林大学学报(地球科学版)》2015,(Z1)
<正>氧化石墨(graphite oxide,GO)是一种层状结构的碳氧化合物,其结构层上的含氧官能团以羟基(-OH)和环氧基(C-O-C)为主,仅在结构层边缘接有少量的羧基(-COOH)和羰基(-C=O)等,这些官能团使GO的结构层表面在水溶液或碱水溶液中带负电,可以通过离子键作用(离子吸附)将阳离子型表面活性剂插入到GO层间,电荷平衡后,进而通过疏水键作用(分子吸附)将有机分子插入GO层间,制得的插层复合物表现出良好的力学、热力学、阻燃、光电、催化等性能,在导电、吸附、耐高温、环保、功能膜和生物传感器等众多领域具有广泛的应用。其中,以GO为前驱体,将季铵盐(CnTAB)分子插 相似文献
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为查明我国典型矿石墨的矿物学特征,采用XRD、FESEM-EDS、TEM和Raman光谱等表征手段对来自不同产地石墨样品的成分、结构与性质进行了研究。结果表明,晶质与隐晶质石墨分别由微米级和纳米级石墨鳞片组成,主要的区别为前者有更大的微晶尺寸;各样品均为2H型石墨结构,同时不同程度地含有3R型多型,轴长a=0.243~0.249 nm,c=0.672~0.677 nm,晶胞体积V在0.0347~0.0362 nm3之间,晶胞体积随晶体结构中O含量的增加而增大。天然产出石墨的石墨化度较高,最高可达1,由于后期地质作用或人工加工改造,引入次生缺陷,导致其石墨化度降低,结构无序度增高。晶质和隐晶质石墨的氧化起始温度分别为700~800℃和600~650℃,粒度越细的晶质石墨氧化起始温度越低。在水中石墨表面荷负电,p H为10.5时具有带电量的极大值,晶质石墨疏水性和导电性均强于隐晶质石墨。 相似文献
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煤中干酪根在热演化中结构变化的红外光谱研究 总被引：1，自引：0，他引：1
为了研究煤中干酪根的不同抽提方法对热演化过程中结构变化的影响,对新疆塔里木盆地库车坳陷阳霞侏罗纪煤中的可溶有机质采用不同的抽提方法得到部分干酪根,并对其在不同热模拟温度下的结构组成变化特征进行红外光谱测定。结果表明,干酪根的结构主要由三部分组成:脂族结构、芳香结构、含氧官能团。随热演化进行,脂族结构和含氧官能团不断脱落,芳香结构不断发生缩合。通过三个系列的比较发现,不同抽提方法导致了初始状态烃类含量的不同,因而红外光谱参数的变化趋势也有所不同。三个系列随热演化程度的进行,从Ⅲ1型干酪根转变为Ⅲ2型干酪根,生油能力降低,主要为生气型干酪根。 相似文献
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鄂尔多斯盆地北东部纳岭沟铀矿床是近年来发现的大型砂岩型铀矿床。与国内外典型层间氧化带型铀矿床明显不同,纳岭沟铀矿床不仅矿体呈板状、似层状产出,受单层灰绿色古氧化砂体与下伏灰色砂体的交界面控制,且远离顶底板,部分含矿岩石在宏观上表现为红色含炭屑矿石,微观上出现铀石-赤铁矿(针铁矿)-黄铁矿等特殊矿物共生组合。在综合岩矿鉴定、电子探针分析、酸解烃分析等成果认识的基础上,结合前人流体障铀成矿理论的实验和数学模拟结果认为,纳岭沟铀矿床是含氧含铀水与深部还原性流体相互作用的产物,且矿体形成过程中含氧含铀水和深部还原性流体的界面变化是红色蚀变矿石形成的关键原因,而持续强的含氧含铀水和较弱的深部还原性流体作用是形成板状矿体的主要因素。 相似文献
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新疆伊犁盆地511砂岩型铀矿床成矿作用机理研究 总被引：5，自引：1，他引：5
为探讨511铀矿床的形成机理,通过野外岩心观察和系统样品采集,结合室内化学分析、扫描电镜、电子探针等方法,详细研究了赋存于Ⅴ旋回砂体的铀矿地质特征,对砂岩铀的成矿作用展开了初步讨论。认为Ⅴ旋回层间氧化带可划分为氧化带、氧化_还原过渡带(包括褪色亚带和铀矿石亚带)和还原带;铀矿赋存在过渡带砂岩中,空间展布严格受层间氧化带控制;铀主要以显微浸染状铀矿物(沥青铀矿 铀石)形式散布于炭屑木质细胞腔内壁和砂岩碎屑颗粒的填隙物中,部分以吸附形式赋存于粘土矿物和炭屑;层间氧化带发育是含氧层间承压水与砂岩之间水岩作用的结果。伴随砂岩中有机质、S2-和Fe2 被氧化,形成的有机酸类、SO2-4和Fe3 等组分部分迁移至过渡带沉淀,也是砂岩中铀元素活化迁移、沉淀富集,再活化、再富集的循环过程;层间氧化带及其砂岩铀成矿作用发生于表生环境,始于喜马拉雅早期(66Ma),具有长期性和滚动式向前发展的特点;铀成矿可能与微生物细菌活动及其还原作用密切相关。 相似文献
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煤系石墨形成于煤层的接触变质带,通常被当作煤开采利用而造成严重的资源浪费.为了了解煤系石墨在成矿过程中分子结构的变化,利用X射线衍射（XRD）、透射电子显微镜（TEM）、拉曼光谱（Raman）等技术,对我国陕西凤县、湖南新化和湖南郴州鲁塘地区处于不同变质程度煤系石墨进行测试分析.结果表明:凤县样品石墨化度最低,仍处于超无烟煤阶段;新化石墨处于半石墨阶段,鲁塘样品石墨化程度最高,其结构比较完美,接近于三维有序理想石墨结构,但仍存在少量的无序化畴.XRD分析显示随着样品石墨化程度的升高,堆砌层数与堆砌延展度均增大;拉曼光谱中D峰减弱,G峰逐渐增强并尖锐,D峰与G峰的强度比和面积比均减小,显示碳原子sp2平面域增大.透射电子显微镜晶格像显示,由无烟煤向石墨结构转变过程中,煤的芳香片层首先形成类石墨结构的微柱体,然后这些微柱体之间相互联结,最后形成横向无限延展的石墨晶层. 相似文献
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A series of cores were obtained from the Great Bay Estuary, New Hampshire during 1980 and 1981 in order to investigate the effects on the dissolved organic matter of exposure of anoxic marine pore water to atmospheric oxygen during laboratory handling. Sediment sections from these cores were homogenized and split into two equal parts, one of which was handled in a glove bag under a nitrogen atmosphere, and the other exposed to atmospheric oxygen during laboratory processing. Analysis of the pore water for dissolved organic carbon (DOC) indicated two effects: (1) in the top 15 cm, DOC was lost from the pore water of the oxidized subsections, probably as a consequence of co-precipitation with iron (III) oxi-hydroxides, whereas (2) deeper in the cores, the pore water from the oxidized subsections showed a net increase in DOC, possibly due to oxidation of sedimentary organic matter. In addition, structural changes in the dissolved organic matter in anoxic pore water following oxidation was indicated by high pressure liquid chromatography and ultrafiltration analysis. 相似文献
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超无烟煤（也称变质无烟煤）中广泛发育石墨微晶，为深入分析煤中石墨微晶产出特征及成因，以福建省永安煤田典型样品为例，采用光学显微镜、扫描电镜和透射电镜等测试方法，识别并分析煤中石墨微晶的光学性质、物质组成、晶体结构等特征，并探讨其成因。结果显示:石墨微晶主要产出于煤中微裂缝和空腔内，多数具有类似于石油焦的纤维状显微结构，可见气泡膜状结构；石墨微晶最大反射率为9.29%~10.83%，远远高于煤中原有显微组分；正交偏光加石膏试板观测条件下，石墨微晶呈现一级黄、二级蓝干涉色以及镶嵌状、区域状、纤维状等显微结构，局部定向性明显。扫描电镜加电子探针探测显示，石墨微晶多呈鳞片状并见流动状结构和气孔构造，同时显示出纯碳特点。高分辨率透射电镜观测到石墨微晶晶格条纹呈平直定向排列，选区电子衍射呈现典型的石墨晶格环斑模式。初步分析认为，煤中石墨微晶的碳质来源于高度熔融的（变）壳质组和富氢（变）镜质体，热源为侵入煤田周边及盆地底部的燕山期花岗岩，熔融含碳物质在孔缝空间内汇聚流动并在高温下脱除杂质元素，然后在强大岩浆侵位压力下结晶形成秩理性显著的石墨微晶；同时，也不排除渗出沥青质体再次活化形成研究区煤中石墨微晶的可能性。移动阅读 相似文献
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为了探究煤系石墨形成过程中结构演化及不同石墨化程度无烟煤和石墨的热反应行为，选取湖南新化系列变质程度无烟煤和煤系石墨为研究对象，通过X射线衍射（XRD）和高分辨率透射电子显微镜（HRTEM）对其结构进行表征，并结合程序控制升温法（TPO）分析不同变质程度无烟煤和煤系石墨的热反应行为。结果表明，随变质程度的增加，碳结构由无烟煤中的无定形态转变成石墨的三维有序C原子点阵。系列石墨化煤是由多种有序度不同的碳结构相组成，体现了其结构非均质性，碳结构相含量及分布随变质程度而逐渐变化，石墨化程度最高的煤系石墨中主要为石墨微晶集合体，但依旧含有结构缺陷。无烟煤和煤系石墨中碳结构的多相性和不均匀分布是影响其热反应行为的重要原因。 相似文献
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《矿物学报》2013,(Z1)
The thermostability, structure, oxidized functional group and hydrophilic of the different reduction temperature of graphene oxide were investigated by TG-DTA, XRD, FTIR, Raman and Water contact angle analysis. There are three stages in the process. The first stage, under 150℃, desorption of adsorbed water on the graphene oxide, hydrophilic is best. The second stage, at 150–300℃, thermal decomposition of partial oxide functional group, graphene oxide was partly thermal reduction, hydrophilic diminishing. The third stage, at 300–550℃, temperature of 300–450℃ when oxidized functional group of graphene oxide is further decomposition, hydrophilic further reduced, temperature of 450–550℃, the carbon skeleton of graphene oxide decomposition. The thermal reduction process of graphene oxide only removed the oxidized functional group their structural deficiencies have not been restored, but due to thermal reduction process and build new structure defect. 相似文献
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The anaerobic degradation of organic matter in Danish coastal sediments: iron reduction, manganese reduction, and sulfate reduction 总被引：27，自引：0，他引：27
We used a combination of porewater and solid phase analysis, as well as a series of sediment incubations, to quantify organic carbon oxidation by dissimilatory Fe reduction, Mn reduction, and sulfate reduction, in sediments from the Skagerrak (located off the northeast coast of Jutland, Denmark). In the deep portion of the basin, surface Mn enrichments reached 3.5 wt%, and Mn reduction was the only important anaerobic carbon oxidation process in the upper 10 cm of the sediment. In the less Mn-rich sediments from intermediate depths in the basin, Fe reduction ranged from somewhat less, to far more important than sulfate reduction. Most of the Mn reduction in these sediments may have been coupled to the oxidation of acid volatile sulfides (AVS), rather than to dissimilatory reduction. High rates of metal oxide reduction at all sites were driven by active recycling of both Fe and Mn, encouraged by bioturbation. Recycling was so rapid that the residence time of Fe and Mn oxides, with respect to reduction, ranged from 70-250 days. These results require that, on average, an atom of Fe or Mn is oxidized and reduced between 100-300 times before ultimate burial into the sediment. We observed that dissolved Mn2+ was completely removed onto fully oxidized Mn oxides until the oxidation level of the oxides was reduced to about 3.8, presumably reflecting the saturation by Mn2+ of highly reactive surface adsorption sites. Fully oxidized Mn oxides in sediments, then, may act as a cap preventing Mn2+ escape. We speculate that in shallow sediments of the Skagerrak, surface Mn oxides are present in a somewhat reduced oxidation level (< 3.8) allowing Mn2+ to escape, and perhaps providing the Mn2+ which enriches sediments of the deep basin. 相似文献
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样品产于南海北部湾滨岸浅滩胶结较松散的长石石英砂岩中,属于上第三系下洋组。本文从海绿石形态、矿物的物理化学测试结果以及形成介质条件等方面,探讨该区海绿石特征和形成环境。 相似文献
17.
《矿物学报》2013,(Z1)
By using hydrothermal synthesis method, successively adding tetrabutyl titanate and expandable flake graphite in 40 mL 0.95% NH4Cl solution prepared the nano TiO2/expandable flake graphite, which was then settled in muffle furnace in the expansion of 10 s under 800 ℃ and got nanosized TiO2/expanded graphite. Synthesized that with CoFe2O4 by chemical coprecipitation method finally prepared magnetic nanosized photocatalyst TiO2/expanded graphite. Magnetic nanosized TiO2/expanded graphite was studied on the photodegradation performance of methyl orange solution and the magnetic recovery after the degradation of methyl orange solution. The experiment result showed that in 50 mL 25 mg/L methyl orange solution joined 120 mg loading 50% TiO2 of the expanded graphite, exposed to ultraviolet irradiation for 1 h, the methyl orange decolorization ratio was 90%. When the load of CoFe2O4 in nanosized TiO2/expanded graphite reached 40%, its magnetic recovery efficiency reached 94.3%. 相似文献
18.
George W. Luther Anne Giblin Robert W. Howarth Robert A. Ryans 《Geochimica et cosmochimica acta》1982,46(12):2665-2669
We used scanning electron microscopy and energy dispersive X-ray analysis to examine sediments from vegetated portions of three salt marshes, the Great Sippewissett Marsh (Cape Cod, MA), Sapelo Island (Georgia), and the Hackensack Meadowlands (N.J.), and from the sediments of an estuary, Newark Bay (N.J.). Pyrite particles were abundant in sediments from all sites. Both fine grained pyrite crystals and framboids were found. Single, fine grained crystals (diameter = 0.2 to 2.0 micrometers) predominated in all samples, strong evidence for rapid formation of pyrite.We also found both microcrystalline and framboidal iron-oxyhydroxide phases in many of the sediment samples. This is evidence of pyrite oxidation within the sediments and suggests that iron is conserved in salt marshes even as pyrite is oxidized. The thermodynamic stability of iron phases in marsh sediments, and recent pyrite oxidation studies in coal, suggest goethite as the crystalline iron-oxyhydroxide phase present. In addition, we sometimes found a red amorphous coating on grass roots from the Great Sippewissett and Sapelo Island marshes. This coating is likely a form of hydrated iron (III) oxide. 相似文献
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为了探讨煤的微孔介孔演化特征及其成因,在华北二叠纪煤盆地,采取7个不同煤化程度的煤样,分别采用低压CO2吸附法和液氮吸附法对各煤样的纳米孔隙进行表征;基于密度泛函理论、DA（Dubinin—Astakhov）、DR（Dubinin—Radushkevich）、BET、BJH等方程计算孔隙表面参数;分析煤的微孔（孔径<2 nm）和介孔（孔径2~50 nm）的孔径分布、孔容和比表面积随煤级变化的规律;并探讨微孔形成的主控因素及介孔的形成机制。研究结果表明:微孔孔容和比表面积与煤的镜质体反射率高度正相关,微孔在吸附中占绝对支配性主导地位;微孔孔径分布曲线呈双峰分布,不同煤级煤样的曲线形态相似,极微孔随煤级增加最快;介孔比表面积和孔容随煤级增加逐渐下降,介孔孔径分布呈单峰分布,随着煤级的增加,煤的BET比表面积先减少后增加,呈U形分布;微孔的形成应主要受控于煤的类微晶参数和芳香层片间的堆垛结构,而介孔的形成应主要受控于煤侧链的变化和煤的基本结构单元间隙。 相似文献
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主要介绍了碳材料在石油废水处理，给排水水质处理、大气治理中的应用。膨胀石墨含有大量孔隙，密度很低，用作吸附材料可以治理石油废水。碳材料可作为生物增殖的载体，分解生物能降解的污染物。用于给排水水质处理，能够提高水质；而经过特殊处理的石墨可以与金属纳米复合，形成金属基石墨层间化合物，改善石墨的抗菌性能。碳材料的比表面积大，可用作气相污染物的吸附脱除材料，在大气污染方面，表现出良好的应用前景。 相似文献