粉煤灰-碳酸钠体系烧结反应的热力学分析

0 引言 粉煤灰的主要来源是以煤粉为原料的热电厂和城市集中供热锅炉,随着我国电力工业的迅速发展,粉煤灰的排放量与日俱增.2005年全国的能源消费量达到22.2亿t标准煤,比2000年增长55.2%,其中煤炭消费21.4亿t,增长了近9亿t.火电行业消耗煤炭11.1亿t,产生粉煤灰约3亿t.因此,如何更高效地利用粉煤灰成为近几年来国内十分关注的重要课题.     

一种能大量消耗粉煤灰的多孔材料的初步研究

以武汉青山热电厂的粉煤灰为原料制作多孔材料.其中的两种样品的孔隙率分别为45.8%和61%.该材料可作为一种消音和隔热材料用于高速公路和城乡建设, 从而大量消耗粉煤灰以达到保护环境的目的      

粉煤灰土壤及所产蔬菜的有害元素含量变化和环境意义

利用南京第二热电厂湿排的粉煤灰,进行了改良蔬菜土壤的试验,并对试验用的粉煤灰、不同施灰量的土壤及所产蔬菜共３８ 个样品的有害元素和放射性元素含量进行了系统的测定。结果表明：这些元素在土壤中的含量与粉煤灰施用量无明显相关性;在本次试验范围内施用粉煤灰没有造成土壤的污染;其所产蔬菜的这些元素含量也均低于国家卫生标准限值,食用是安全的。     

粉煤灰改性膨胀土水稳定性试验研究

针对典型中膨胀土及其粉煤灰改性土,进行了击实特性试验,并且在最优含水率、不同压实度状态下,进行了饱水后干密度、压实度变化特征试验,以及不同吸水时间、不同干湿循环次数下的无侧限抗压强度、压缩模量变化规律试验,以此探讨中膨胀土、粉煤灰改性膨胀土的水稳定性特征。试验结果表明：粉煤灰改性土可击实含水率范围较之未改性土宽,这给粉煤灰改性土路堤的施工带来了很大的方便。饱水之后,改性土的干密度和压实度比素土变化小,饱水能力不大,强度变化较小。改性土经过不同吸水时间和干湿循环次数之后,其强度最初发生急剧衰减,但最终趋于稳定。其衰减程度较之未改性土来说,有较大改善,水稳定性良好。     

粉煤灰的矿物学研究及其成因分析

燃煤热电厂的废尘,国外叫飞灰(Fly Ash),我国称粉煤灰,世界每年排放约一亿六千多万吨,而我国年排放量便有三千七百万吨之多.这些废尘目前只小部份被利用于建材、筑路、农业和填充土等,大部仍被废弃、污染大气和水域.近年来为探索扩大粉煤灰综合利用的途径,作者首次应用多种分选方法对粉煤灰的物质成份进行了分离富集,并配以有关手     

西峪煤矿采空区上方泉水断流后复出的机理

从西峪煤矿寨沟井田二水平2619、2617工作面采空区上方地表泉水断流10年后又复出的现象出发,对泉水断流、复出并逐渐增大的机理进行了比较全面而深入的研究。得出泉水的复出是由于石岔沟内粉煤灰浆水沿着原来泉水的出口处溢到地表所致。故而进一步推出西煤矿采空区上方地表裂缝不必要充填的结论,也为热电厂处理粉煤灰以及其它煤矿在今后治理、美化矿山环境中指出几条有借鉴意义的方法和途经。     

粉煤灰土壤主所产蔬菜的有害元素含量变化的环境意义

利用南京第二热电厂湿排的粉煤灰,进行了改良蔬菜土壤的试验,并对试验用的粉煤灰,不同施灰量的土壤及所产蔬菜的３８个样品的有害元素和放射性元素含量进行了系统的测定。结果表明：这些元素在土壤中的含量与粉煤灰施用量无明显相关性;在本次试验范围内施用粉煤灰没有造成土壤的污染,其所产蔬菜的这些元素含量也均低于国家卫生标准限值,食用是安全的。     

粉煤灰室内水力冲填试验研究

针对山东某电厂灰坝加高工程,依据粉煤灰水力冲填筑坝的要求,通过室内冲填模拟试验,分别研究冲填厚度、不同振密方法对水力冲填粉煤灰密度、饱和度、渗透特性的影响。试验结果得出：粉煤灰充填厚度对充填效果影响不大,而振动压密的方法对充填效果影响很大。     

充填结构包气带水分运动参数试验研究

煤炭开采引起大面积沉陷,利用粉煤灰或煤矸石作为充填介质,并覆盖一定厚度土壤的方法进行土地复垦是一种重要的充填模式。以粘质土壤、粉煤灰、煤矸石为研究对象,采用室内试验方法分别测定其物质的水分特征曲线、非饱和导水率曲线、容水度、水分扩散度等充填结构包气带的水分运动参数,为研究土壤-粉煤灰、土壤-煤矸石充填结构包气带水分运动规律提供参考依据。     

利用吉林省粉煤灰制取结晶三氯化铝试验

本文主要研究利用吉林省粉煤灰制取三氯化铝,在国内外利用粉煤灰提取铝或生产铝制品的试验的基础上,针对吉林省粉煤灰的特征,经过试验方法的选择研究,开展了相应的小试研究,进而总结了利用粉煤灰制取三氯化铝的相关技术条件与相关的技术参数。     

Utilization of leonardite and coal bottom ash for production of ceramic floor tiles

The aim of this research was to exploit leonardite and coal bottom ash (CBA), which are waste products from coal power plants, for investigating their potential as raw materials in the production of ceramic floor tiles. The developments of ceramic body were mixed with traditional raw materials. Different proportions of ceramic materials were studied in order to explore the proper composition with a variety of wastes containing leonardite and coal bottom ash from 20% up to 80%. Unglazed tiles were produced by shaping through dry pressing and single firing. The physical, chemical, and mechanical properties of the samples were investigated. The total waste (CBA and leonardite) contained in the production was close to 42.8%, and it presented properties that are adequate for it to be classified in groups within the ISO 13006 standard, and yielded the highest flexural strength which enabled the obtained ceramic floor tile bodies to satisfy the requirement to be classified in group BIIa. The chemical resistances of the products were classified in the category UA group which passed the minimum requirement for classification as chemical attack, set by standard EN 14411.     

煤中微量元素研究进展

煤炭是我国的主要能源，在煤炭开采、运输、洗选、淋溶（滤）、燃烧等其它加工利用过程中，煤中的微量元素要发生迁移、析出，并入侵到大气、水、土壤和生态环境中，最终影响人类生存和生活环境。煤中微量元素十分重要，是因为它们与环境问题、动、植物及人类健康密切相关。在研究微量元素时必须考虑微量元素的性质及毒性，它们主要依靠其含量、种类、存在形式、pH值、氧化-还原条件及其它因素。在全面综合国内外研究文献的基础上，分析了煤中微量元素的发现、分布规律、赋存状态、成因机理及微量元素的应用等方面研究的历史、现状，并对今后研究的重点内容和发展方向进行了较为详细的论述和分析，并指出在进一步深入研究煤中微量元素地球化学的基础上，加强微量元素环境学方面的研究是今后煤中微量元素环境地球化学研究的重要内容。     

Fine coal covering for preventing spontaneous combustion of coal pile

In order to investigate the effect of fine coal covering around the bottom of coal stockpile on spontaneous combustion prevention, a two-dimensional math model was established to numerically simulate the fine coal covering coal pile and a coal pile temperature-rising experimental system was setup to study the two-dimensional heat and mass transfer characteristics of air diffusion in the horizontal direction and air heat convection in the vertical direction inside coal stockpiles covered by different thicknesses of fine coal. The results showed that (1) the fine coal located at the bottom of the coal pile can effectively inhibit air convection and diffusion, cut off oxygen replenishment, and prevent the temperature rise inside coal pile, and (2) thicker fine coal has more obvious effect. Finally, the field experiments on the fine coal covering coal piles for preventing self-ignition of coal pile were carried out successfully. The results showed that the uncovered or exposed coal piles self-ignited rapidly within a very short period (18 days), while the coal pile covered with 1 m fine coal lasted for 123 days with a maximum coal temperature of only 59.9 °C. The characteristics of temperature distribution and diffusion inside coal stockpile were studied, and the high-temperature region was found in the region 1.3 m high and 2–3 m deep in the coal pile. The effects of environment temperature and precipitation on self-ignition of coal pile were also analyzed in field experiment. The experimental results proved that the fine coal covering technology can effectively prevent the spontaneous combustion of coal stockpiles.     

大气气溶胶密度观测研究进展

大气气溶胶的气候效应、环境效应、健康效应均与其物理化学性质密切相关,其中,密度是大气气溶胶重要的物理性质之一。密度影响着粒子的输送过程和在人体肺部的沉积过程。密度可以分别将电迁移率粒径和空气动力学粒径,数浓度和质量浓度联系起来。密度的变化可为气溶胶的形成和老化过程提供信息,细粒子分粒径的密度还可为大气过程和化学组分的演化提供参考依据。因此,研究大气气溶胶密度对了解气溶胶化学组分,评估气溶胶形成过程以及探究气溶胶在人体内的沉积效率具有重要的意义。由于国内在该领域研究总体较少,对大气气溶胶密度的定义、研究方法、国内外研究进展以及影响因素和变化特征等进行较为系统的总结,对未来开展大气气溶胶密度的观测和研究十分必要。     

论煤地质学与碳中和

煤基碳排放构成了中国碳排放总量中最重要的部分,做好煤基碳减排和煤炭高效洁净低碳化利用是实现“碳中和”国家目标的重要途径,碳中和背景下的煤地质学发展值得关注。系统评述与碳中和相关的煤地质学研究领域,分析煤地质学在碳中和研究与工程实践中的作用和应用前景,探讨碳中和背景下煤地质学的重要发展方向。取得以下认识:推进清洁煤地质研究、服务煤的高效洁净化燃烧,勘探开发煤系天然气低碳燃料、优化一次能源结构和化石能源结构,开展煤化工资源勘查与开发地质保障研究、推动煤炭的低碳能源转化和新型煤化工产业发展,深化瓦斯地质研究、提高煤矿瓦斯（井下）抽采率、控制煤矿瓦斯的大气排放和泄漏,研究煤层甲烷天然逸散和煤层自燃排放、控制煤层露头的天然排放,发展煤层CO₂地质封存与煤层气强化开发（CO₂-ECBM）技术、推动碳捕获、利用与封存（CCUS）技术发展及其在火力电厂烟气碳减排中的商业化应用,研究煤炭勘查企业的碳足迹、实现企业净零排放,是与煤地质学紧密相关的碳减排技术路径;其中煤层甲烷与煤系气高效勘探开发、深部煤层CO₂-ECBM、煤层露头气体逸散与自燃发火控制、洁净煤地质与煤炭精细勘查是碳中和背景下煤地质学优先发展的重要领域。      

Differentiation of charcoal,soot and diagenetic carbon in soil: Method comparison and perspectives

The various sources of pyrogenic and coalified carbon (black carbon, BC) in soil have considerable structural heterogeneity, making the quantification of BC a challenge. This study was aimed at evaluating the capability of different detection procedures to recover different types of BC from soil. We added defined quantities of urban dust (UD, NIST SRM1649a), diesel particulate matter (DPM, NIST SRM2975), charcoal, lignite, bituminous coal and wood to four topsoil samples. Mixtures were analyzed by way of chemo-thermal oxidation (CTO), thermal gradient oxidation (ThG), the benzene polycarboxylic acid method (BPCA) and mid-infrared spectroscopy (MIRS). CTO returned good quantification of soot BC in the pure DPM, yet the recovery of soot BC from soil was unsatisfactory (18–270%). ThG gave good precision but lower values for pure soot BC. It severely overestimated the BC content for all soil-standard mixtures. The BPCA method gave a low return for soot BC, but for the spiked soil it reliably detected charcoal and coalified C (69–107% avg. recovery) but underestimated soot BC (52–90% recovery of DPM). Linear coherence in specific MIR vibrations was found in one component soil-BC mixtures for each BC type. Applying these standard calibrations to multi-component mixtures allowed detecting charcoal and a quantification of soot BC (88% avg. recovery) via MIRS, but ignored the presence of diagenetic C. We see the greatest potential in differentiating soot from charcoal in soil by employing a combination of chemical and thermal oxidation and MIRS, while the differentiation from diagenetic C is not possible yet.     

重庆永川煤矿煤岩热物性参数特征

煤岩热物性参数是矿井降温、防灭火治理工作所需要的重要基础资料。以重庆永川煤矿为研究对象,采用井下现场测定和实验室测试对该矿目前采掘区域内煤岩密度、比热、导热系数、导温系数以及原始温度、地温梯度等参数进行了测试。测试结果表明,在矿井标高-400 m水平,煤岩样的密度、比热、导热系数、导温系数均处在正常范围之内;在标高-357~-438 m,煤岩密度、比热、导热系数、导温系数不随标高的变化而变化。在标高-400 m水平,煤岩原始温度为35~36℃;矿井恒温带深度以下,-400 m水平以上的地温梯度为2.32/℃ hm,-400 m水平以下的地温梯度值为2.65/℃ hm,存在一个稍微递增的趋势,但仍然处于正常地温梯度范围。结合矿井地勘资料确定煤岩原始温度的实测值较理论计算值偏小,但误差不超过3%,精度符合工程实际要求。      

Interactions between organic matter and minerals in two bituminous coals of different rank

The association between specific mineral and organic constituents in two Asturian bituminous coals of different rank was studied. For this, raw coals were fractionated by density and the variation of a number of parameters was followed in parallel. Results of coal chemical analyses, including analyses for 22 elements, were used to establish the elemental association with coal organic matter. Petrographic analyses determined the distribution of macerals among densimetric fractions, vitrinite reflectance being at a minimum in the intermediate density fractions. Mineral species were identified by X-ray diffraction, FT-IR spectroscopy and Mössbauer spectroscopy. Comparison of trends for different parameters determined using this set of techniques allowed classification of the various minerals according to their association with organic matter. Carbonates seem to be specifically associated with the organic matter of the low-volatile bituminous coal whereas sulfides concentrate in the organic matter of the high-volatile bituminous coal. Vitrinite is the maceral exhibiting the most probable association with inorganic matter. The possibility of a merely physical association of fine-grained detrital minerals with organic matter cannot be excluded; nevertheless, one must bear in mind that even this type of interaction is important due to its effect on various coal preparation and utilization processes.     

Leaching Behavior of Fly Ashes from Power Plants

The Yanzhou mine district, located in southwestern Shandong Province, is about 1300 km2 with more than 8×109tons of proved coal reserves and there are 10 big power plants in this area. A large amount of coal ashes, which are regarded as waste materials, have been stockpiled in the area and have influenced the environment of the mine district. In this paper, analysis of fly ash samples from three power plants is carried out, the enrichment and concentration of trace elements, Pb, Zn, Cu and As, in coal ashes are analyzed, and petrological and mineralogical characteristics and chemical compositions of coal ashes are studied. The aim of this work is to provide basic scientific data for utilization of ashes and reduction of environmental pollutions.     

显微组分大分子结构演化差异性及其动力学机制——研究进展与展望

显微组分物理化学性质是影响煤炭清洁高效利用和煤储层物性的重要因素,已经认识到决定显微组分性质的根本原因在于其大分子结构。为了揭示显微组分大分子结构演化特征及其控制因素,从显微组分大分子化学结构与物理结构、大分子结构演化的构造应力效应、煤变质全阶段大分子结构演化特征等方面,总结了国内外研究进展,分析了存在的不足。指出由于富镜质组煤的广泛分布和重要工业用途使之成为煤结构研究的主要对象,惰质组的研究则相对缺乏,阻碍了对煤特性的全面认识。提出“煤变质作用的热-应力条件决定显微组分结构演化、惰质组与镜质组大分子结构演化具有差异性”的研究思路,采用惰质组/镜质组高温高压模拟和热模拟实验并与自然序列变质-变形煤对比,研究显微组分结构演化特征及其控制因素。定量刻画显微组分大分子结构与温压条件的关系,揭示构造应力对显微组分化学结构和纳米孔隙结构的控制,确定煤变质全过程中惰质组大分子结构的演化路径,建立惰质组大分子动力学模型。上述研究成果将充实对煤微观结构演化及其控制因素的全面认识,为煤炭清洁高效利用和煤储层物性评价提供基础依据。