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用库仑滴定法代替重量法测定煤灰中的三氧化硫 总被引:1,自引:0,他引:1
国标中规定的分析测试方法为重量法,其测试过程繁琐、耗时长,容易产生分析误差,并且每次测试的重现性差。采用煤灰燃烧后库仑测定的方法来测试煤灰中的硫,以提高分析测试的精密度和准确度,提高工作效率。 相似文献
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在炉膛内的高温下,几乎所有煤中的汞转变成元素汞并停留在烟气中。在型煤燃烧过程中,汞的形态变化受到诸多因素影响,包括给煤煤种、给煤的汞浓度、给煤的其他元素浓度、烟气温度和烟气成分、煤灰物理性质以及汞及其化合物在烟气中停留时间的长短等等。本文通过研究汞含量不同的型煤燃烧的温度、燃烧时间等条件,汇总大量数据,找出汞析出的规律,为下一步找到合适的控制方法提供参考。 相似文献
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在小型热态循环流化床试验台上进行褐煤、烟煤、无烟煤燃烧试验,研究3种典型煤的烟气气态汞和飞灰颗粒汞迁移规律。试验结果表明:褐煤、烟煤、无烟煤在燃烧过程中,炉膛温度、空截面风速、给煤量以及煤颗粒大小变化时,汞元素在烟气和飞灰之间的迁移规律相似;降低炉膛密相区温度和增大炉膛空截面风速可促进烟气气态总汞HgT(g)迁移到飞灰颗粒汞Hg(p)中,同时也促进烟气气态零价汞Hg0(g)向烟气气态二价汞Hg2+(g)和Hg(p)转化;增加给煤量,烟气气态总汞HgT(g)和烟气气态零价汞Hg0(g)减少,飞灰颗粒汞Hg(p)含量增加,并且影响Hg0(g)的转化;选择合适的煤颗粒粒度可以促进Hg0(g)的转化以及HgT(g)向Hg(p)迁移。随燃烧工况的变化,3种煤HgT(g)、Hg(p)和Hg0(g)含量变化趋势相似,但含量相差较大,Hg0(g)占HgT(g)的比例y值也不同,其中无烟煤的y值高于烟煤和褐煤的y值。 相似文献
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对砷钼蓝分光光度法和氢化物发生—原子荧光光谱法测定煤中砷的含量进行了比较分析,2种方法分别在砷含量0~50μg/g、0~40μg/g范围内符合朗伯—比耳定律,线性相关性良好;分别用2种方法对砷含量在0~40μg/g范围内的10个样品各进行2次重复测定,利用t检验和F检验法分别对2种方法的正确度(偏倚试验)和精密度进行了评估,得出氢化物发生—原子荧光光谱法与砷钼蓝分光光度法相比没有实质性偏倚的存在,2种方法的精密度均在规定范围内。 相似文献
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A distinction is proposed between mineral coal and extracted coal. Mineral coal is a complex natural composite that is found in underground beds, while extracted coal is created from mineral coal in working those beds. It is important to keep in mind that mineral coal is created by natural processes, whereas extracted coal is produced by human activity. 相似文献
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A high-volatile bituminous coal was extracted at room temperature by various organic solvents. The yields of the extracts ranged from 4.5 wt% daf (ethanol/benzene extract) to 38 wt% daf (pyridine/ethylenediamine extract). The extracts were analysed by Fl mass spectrometry; the volatile part (75–80 wt%) was composed of substances of molecular weight in the range 70–800 amu, but the compounds in the 200–600 amu range predominated. Over 300 compounds were identified by high-resolution mass spectrometry. The results indicate that compounds < 800 amu constitute at least 30 wt% daf of the analysed coal. 相似文献
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Electrical conductivity of coal and coal char 总被引:2,自引:0,他引:2
Alfred G. Duba 《Fuel》1977,56(4):441-443
The electrical conductivity of coal, at either 1 kHz or d.c., was measured at 24 °C on samples recovered from pyrolysis experiments aimed at modelling conditions during in situ gasification of coal. From an initial value of 10−3 S/m (when the coal is saturated with formation water), the conductivity decreases to 10−8 S/m when the coal is heated to 110 °C in vacuum. This low value, presumably due to dehydration of the coal, prevails for samples heated as high as 500 °C in dry argon. Samples of char recovered after pyrolysis to 800 °C or more have a conductivity of 102 S/m. Capitalizing on the large contrast between the conductivities of coal and char produced during gasification, electrical probing may be a sensitive tool for monitoring ‘burn-front’ progress during in situ coal gasification. 相似文献
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对澳大利亚煤和国内6种单种煤进行煤质分析和配煤炼焦实验,分析澳大利亚煤代替西曲煤进行炼焦的可行性。结果表明澳大利亚煤具有低灰低硫、高挥发分等特点,在炼焦中用澳大利亚煤替代西曲焦煤可降低焦炭的灰分和硫分,增大焦炭的各向异性指数,改善焦炭强度。 相似文献
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P. V. Shtark Yu. V. Stepanov N. K. Popova D. A. Koshkarov N. V. Tsarev D. V. Vorsina 《Coke and Chemistry》2008,51(3):85-87
For many years, Kuznetsk-coal batch has always included bituminous coal. Depending on the content of such coal, the batch may be characterized as lean, moderately clinkering, or bituminous. This classification was adopted by specialists of the Eastern Coal-Chemistry Institute (ECCI) in experimental coking at Magnitogorsk Metallurgical Works in 1945 [1]. Lean batch contained 10% Osinovsk bituminous coal (plastic-layer thickness y = 13 mm); moderately coking coal contained 25% bituminous coal (y = 16 mm); and bituminous batch contained 40% of such coal (y = 20 mm). 相似文献
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为了利用内构件反应器热解技术实现黏结性煤的高值化利用,采用TG-MS和固定床反应器研究了黏结的山西兴县煤(简称XX煤)与不黏的先锋褐煤(简称XF煤)共热解时的破黏和热解特性。TG-MS实验结果表明,XX煤与XF煤配制的混合煤比XX煤黏性小,且XF煤促进了XX煤热解,混合煤热解行为是两种煤共同作用的结果。固定床热解实验表明,煤粒径越小,降黏越显著;XX煤和XF煤的比例(XX:XF)越小,降黏越显著,XX:XF小于5:5时,可消除结焦团块;XX:XF越小,半焦产率越低,焦油和煤气产率越高;随XX:XF减小,焦油中<170℃和230~300℃的馏分含量先升后降,XX:XF=6:4~3:7时最高,170~210℃、210~230℃和300~360℃的馏分逐渐增加,>360℃的馏分含量不断降低;随XX:XF的减小,H2含量先升高后降低,在XX:XF=3:7时最高;CO含量呈略微升高趋势;CO2含量先逐步升高,在XX:XF=6:4达到最高,然后从XX:XF=5:5开始降低,在XX:XF=3:7达到最低,然后又开始升高;CH4及C2~C3组分含量呈下降趋势,而H2+CO+CH4 (煤气中有效组分之和)的含量先下降再升高接着再降低,在XX:XF=6:4时最低,XX:XF=3:7时最高。XX:XF越小,虽半焦的C/N和C/H不断减少,但C元素含量增幅和N, H元素含量减幅增大;比表面积越大,内孔结构越多越大,起燃温度越低,燃烧越彻底。 相似文献
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科学合理的配煤技术对于焦化企业高质量发展至关重要,炼焦配煤技术的核心在于对原料煤煤质特性的深入认知。影响炼焦煤性质的主要因素包括变质程度、煤岩组成及第三成因因素,故煤岩学对炼焦配煤技术的研究与应用至关重要。本文论述了经验配煤、煤岩配煤及人工智能配煤3种炼焦配煤技术发展历程和现状,凝练了炼焦配煤技术的发展趋势。结合研究实际,重点梳理了煤岩学指标在炼焦配煤中的应用现状。在注重煤岩特征的同时,也需兼顾工艺指标等相关参数对炼焦煤优劣的表征。在实际应用中,各项指标参数的选择和利用需要综合考虑参数适配范围并尊重该指标与炼焦煤特性的真实对应关系。基于以上内容,提出了关联成煤时代、产地等地质因素和黏结指数、胶质层指数等工艺指标的整体思路,实现焦炭性能与原料煤特性的科学、深入关联,构建“本源-过程-结果”一体的优化配煤技术新体系。 相似文献
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The coking properties of coal pitch depend significantly on its fractional composition, which determines the set of structural
components involved in meso-phase formation. The optimal combination of high-molecular aromatic compounds, polycyclic compounds
of intermediate molecular mass, and hydrogen-donor hydroaromatic components corresponds to a ratio of pitch fractions α: β:
γ = 1: 2: 2. This is typical of coal pitch with a softening temperature of 75–85°C. Such pitch is the best clinkering additive
to coking batch, resulting in the production of coke of maximum strength. 相似文献