煤沥青对不同变质程度煤成焦性能的影响

第36卷第2期煤炭转化Vol. 36 No. 22013年4月COAL CONVERSIONApr. 2013煤沥青对不同变质程度煤成焦性能的影响白永建"许德平2) 王 永刚2)摘要为了考察煤沥青与不同变质程度煤的共炭化特性,利用40 kg小焦炉模拟炼焦试验，进行了单种煤5%与10%的煤沥青添加的各煤种的炭化研究.研究结果表明，沥青对不同变质程度煤生成焦炭的显微结构影响不同.对低变质程度的中低黏结性煤,增加了焦炭光学组织指数OTI;对黏结组分充足的中等变质程度煤的OTI影响较小;对高变质程度煤OTI影响显著.沥青对不同变质程度煤生成焦炭的机械性能影响不同.对低变质程度的中低黏结性煤,溶解作用较明显,对机械强度有较大改善;对黏结组分充足的中等变质程度煤的成焦性能影响较小;对高变质程度煤成焦性能影响最为明显,可显著改善焦炭机械性能和热性质.关键词煤沥青,变质程度,热性质,结焦性能中图分类号TQ520. 60引言1实验部分煤焦油沥青是高度缩聚的碳环和杂环化合物组1.1实验用煤成的高分子有机物,具有与煤同源的组成和结构,但在环构化程度和分子组成上存在差异，炭化时体现选用不同变质程度的6种煤,全部为洗精煤,分较高的流动性,可用于增强原料煤的黏结性.在配煤别来自山西各煤矿和陕西(长焰煤),其分析数据见或单种煤添加煤沥青后,能提高焦化过程中煤料塑表1.由表1可知,两种低变质程度的长焰煤和气性物的流动度,促进不熔融煤粒的湿润,使煤质均匀煤,其黏结指数G较低,分别为13和68.两种中等化,改善煤的成焦性.[18]利用煤沥青良好的润湿性变质程度的肥煤和焦煤,其黏结指数较高,具有较高及结焦能力,炼焦工业可用作配煤的活性黏结剂以的黏结性和结焦性.而较高变质程度的瘦煤和贫瘦提高配煤中的活性组分.煤沥青与煤共炭化时的相煤,其黏结指数较低,分别为56和16.互作用程度,取决于沥青和煤的性质.如果煤沥青与表1实验用煤的性质Table 1 Proximate and ultimate analysis of coals煤共炭化时是相互独立的，就不会对煤发生改性作SampleAses/% Vau/% Sas/% GRI Y/mm Rmx/%用,而只是我们理解上的物理熔融黏结.如果沥青在Long flame coal 5.37 39.47 0.42 13.0 00. 534与煤共炭化时能溶解煤的组分,经过中间相生成焦Gas coal5.52 40.19 0.52 68.011.00.712炭,则是我们理解上的化学作用.化学作用的结果使28.5 1.088Coking coal 10.43 21.76 1.06 88.5 18.9 1. 253得焦炭的显微结构发生改变,使得生成焦炭的各向Lean coal8.97 17.33 1.09 56.012.7 1. 611异性程度增加.沥青的供氢性以及其塑性物的流动Meager lean coal 10.21 13.43 0.43 16.001.797度是体现这一作用程度的重要参数,而煤的性质也1.2 煤沥青决定相互作用的程度.[7:9]本研究在选定的沥青条件下,系统考察沥青与不同变质程度煤炭化的配伍性，本实验用煤沥青来自山西某焦油加工企业,其通过测定共炭化焦炭的显微结构和组成,分析煤沥灰分为0.11% ,挥发分为56. 21%,硫分为0. 44%.青对不同变质程度煤的作用程度和机理，更好地指煤沥青单独成焦焦炭块度大,呈银灰色光泽,气孔.导实际炼焦生产实践.多,呈蜂窝状，-中国煤化工应性CRI为*国家自然科学基金资助项目(21076222).YHCNMHG1)博士生;2)教授,中国矿业大学(北京)化学与环境工程学院, 10083北京收稿8期:2012-10-19;修回日期:2012-12-30.6煤炭转化2013年71.7,反应后强度CSR为29. 6.沥青焦的光学显微温为1050C,结焦时间控制为10h.焦炭Moo,Mzs组织特征见表2.由表2可以看出,沥青焦的光学组和M。按GB/T2006-94《冶金焦炭机械强度的测织异性程度较高,主要是中粗粒镶嵌结构,光学组织定方法》测定，焦炭光学显微结构按YB/T077-指数OTI接近200.1995<焦炭光学组织的测定方法》测定,焦炭反应性表2煤沥青焦的光学组织结构和反应后强度按GB/T 4000- -2008《 焦炭反应性及Table 2 Optical structure of coal tar pitch反应后强度试验方法》测定.Medium and FlowDis continuousIsotropicgrain set corse mosicsrDomaindomnainZIso oT12结果与讨论3.190.8 1.5 2.1.95.0 196.91.3 实验过程将单种煤粉碎至<3 mm,混匀捣固至密度为2.1煤沥青与低变质煤的共炭化0.95 g/cm ,水分调整至9.5%.利用40 kg小焦炉煤沥青分别与低变质程度的长焰煤和气煤共炭模拟炼焦,按照煤沥青5%与10%的比例分别添加化成焦,沥青的添加量分别是0%,5%和10%.炭化到低、中、高变质程度的煤中进行焦化实验.炭化终成焦后的光学显微结构和机械强度见表3.表3煤沥青与低变质程度煤共炭化焦炭性质Table 3 Properties of coke from cor-carbonization of coal tar pitch and low rank coalMedium andBasicSamplelorop Fine mosis Corse mosaiesFlow typeDormain Fusiniteaisitopio2Iso OTI Mo Mzs MoLong flame coal80.71..796.6 8.5 0 0 100Long flame cal+5% coal tar pich 67.0.2.028.795.7 10.7 11.8 26.5 64.7Long flame coal+ 10% col tar pich 71.06..9.10.18.489.4 17.0 70.0 83.13.Gas coal2.92.4.61.:45.680.510.Long flame col2045.187.1 23.8 69.4 83.5 5.Long fame coal+5% coalarpich_ 69.4..320.689.9 21.8 76.0 85.8.由表3可见，与原煤单独炭化相比,低变质程度别为29.6,31.5和22.0,反应性和反应后强度变化长焰煤中配人不同比例的沥青后,光学各向同性组没有呈现明显的规律.分含量明显减少,细粒镶嵌组分含量增加.尽管不同从以上结果可以看到，沥青明显改善了长焰煤各向异性程度的组分随沥青添加量增加呈现一些不的炭化特性,提高了焦炭显微组分的各向异性程度规则的波动,但总体趋势是光学组织指数OTI逐渐和机械性能.低变质煤含有较高的含氧官能团,交联增加,由8.5分别增加到10.7和17.反应性较强,单独炭化时不容易生成稳定的液相组值得注意的是沥青添加明显提高了生成焦炭的分,因而没有黏结性,或呈现较弱的黏结性.与沥青机械性能.沥青添加量为5%和10%时,生成焦炭的共炭化,沥青将煤热解组分有效溶解,促进了中间相抗碎强度M。由0分别提高到11.8和70,M25也有的生成,使焦炭的光学性能得到改善.同时,也改善相同的规律.耐磨强度Mo由100 改变为64.7和了焦炭的机械性能.13. 0,耐磨性能显著提高.2.2煤沥青与中等变质程 度煤共炭化由表3还可见，与原煤单独炭化相比,低变质程第61页表4是煤沥青与中等变质程度两种煤度气煤中配人不同比例的沥青后,光学各向同性组共炭化的焦炭性质.由表4可知,添加沥青进行炭化分含量略有增加，细粒镶嵌和粗粒镶嵌组分含量有后，肥煤的焦炭的各向同性组分含量略有下降,细粒些波动,光学组织指数OTI随沥青添加量增加也呈镶嵌含量上升,中粗粒镶嵌和流动性组分略有下降，现一些不规则的波动.整体结果是焦炭的光学指数OTI没有明显变化.从沥青添加对低变质程度气煤的机械性能影响不生成焦炭的机械性能来看,Mso和M25略有下降,M1o明显,M。o呈现增加的趋势,由单独炭化的57.2分略有上升.焦煤与沥青的共炭化,大致呈现相同的规别增加到69.4和76,M2s略微增加,Mo变化不明律，只是有些数据的波动.其光学显微组分含量变化显;此外,还测定了沥青与气煤共炭化焦炭的热性不明显,光学MH中国煤化工有变化，M。和质,对应于沥青添加量为0%,5%和10%,其反应性M2s略有降佴CNMH G青对中等变质CRI分别为53.0,55.8和46.5;反应后强度CSR分程度的肥煤、焦煤的成焦性能修饰无明显作用..62煤炭转化2013年数OTI,如瘦煤添加较大量的煤沥青时可发展到流强度.与同属低变质程度的气煤共炭化,尽管增强了动型组分.同时沥青也能改善界面的结合状态,提高焦炭的各向异性程度,但对机械性能的改变不大.沥了结焦性能.青与黏结组分充足的中等变质程度煤共炭化时,对生成焦炭的光学显微组分影响较小,对焦炭的机械性能也影响较小.煤沥青与高变质程度煤共炭化,改.善或沥青的修饰效果较明显，焦炭的光学显微结构改变较大,焦炭的机械性能改善明显.煤沥青与煤共炭化具有改变焦炭显微结构与增加焦炭裂纹和空隙的双重效应,两者对机械性能的贡献是相反的,两者可以相互补偿.当沥青对焦炭光学各向异性的影响较强时,体现为显微强度的增强，这在低变质和高变质煤与沥青的共炭化时都得到了图2中 粗粒镶嵌组分Fig.2 Component inlaid by middle and coarse grain体现.当沥青对焦炭光学各向异性的影响较弱时,则观察不到显微强度的明显增强,这在中等变质程度煤与沥青的共炭化时得到了体现.3结.论1)沥青对不同变质程度煤生成焦炭的显微结构影响不同.对低变质程度的中低黏结性煤,增加了焦炭组织指数OTI,对黏结组分充足的中等变质程度煤的OTI影响较小，对高变质程度煤OTI增加明显2)沥青对不同变质程度煤生成焦炭的机械性图3 流动型组分Fig. 3 Component of flow model能影响不同.对低变质程度的中低黏结性煤,溶解作煤沥青与不同变质程度煤共炭化呈现了不同的用较明显,对机械强度有较大改善;对黏结组分充足规律.由以上结果可以看出,在炼焦配煤中,煤沥青的中等变质程度煤的成焦性能影响较小;对高变质与低变质程度的长焰煤共炭化时,热溶解作用较明程度煤炭化性能影响最为明显,可改善焦炭机械性显,增强了焦炭的各向异性,同时提高了焦炭的机械能和热性质.参考文献[1]肖瑞华.煤焦油化工学[M].北京:冶金工业出版社.2002:240-257.[2]申峻,邹纲明,王志忠.煤与各种舔加物共碳化的研究进展[J].煤炭转化,1999,22(3):6-9.[3]李颜冰，吴斌译.各种煤加入煤焦油沥青的碳化[J].国外炼焦化学,1995(5):261-266.[4] 任先顺,白永建,杨双凤等.贫煤与煤沥青共炭化研究[J].燃料与化工,2010,41(2):15-17.[5] Mochida I,Matsuoka H,Korai Y et al. 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Fuel,1987 ,66(8) :1019-1023.[9] 郑明东，王晓燕.影响焦炭热态性质的因素探讨[J].燃料与化工,2008,39(2):1-4.中国煤化工78页)MHCNMH G.78煤炭转化2013年STUDY ON INFLUENCE OF HEAT BINDER ON PROPERTIESOF BRIQUETTE FROM LOW RANK BITUMINOUS .COALS UNDER HOT STATEHuang Shanxiu and Ma Mingjie(School of Materials Science and Engineering, He' nan PolytechricUniversity, 454000 J iaoruo, He' nan)ABSTRACTTwo different materials such as coal tar pitch, fat coal with high adhesion werechosen as the heat binder, which were mixed into the powder of low rank bituminous coals fromShenmu or Yuzhou and other raw materials to make coal briqutte in different ration. The deter-mination results show that the thermal strength of coal briquette with tar pitch is higher than thatof coal briquette with fat coal. Further analysis of micro-structure of coal briquette by electronmicroscopic also verifies that the cohesion and water resistance of coal briquette with tar pitch isstronger, and it is because that interaction of air bubble poduced by volatile separated under hotstate through colloid pressures the colloid and form the stronger net -structure on coal granulessurface. Moreover, the particle size of tar pitch also have certain effect on thermal strength ofcoal briquette.KEY WORDS low rank bituminous coal ，coal briquette, thermal strength, heat binder, mi-cro-structrue, particle size of pitch(上接第62页)EFFECT OF COAL TAR PITCH ON THE COKING PERFORMANCESFROM DIFFERENT RANK OF COALSBai Yongjian Xu Deping and Wang Yonggang(School of Chemical and Environmental Engineering，China Universityof Mining and Technology, 100083 Beijing)ABSTRACT To study the co-carbonization between coal tar pitch and different rank of coal,experiments of charring between 5% and 10% of coal tar pitch and coals were studied, whichwere test in coke oven of 40 kg. The results showed that, the microstructures of cokes charredfrom different rank of coals and coal tar pitch were different. The pitch increased the OpticalTexture Index (OTI) of the coke from low rank of coals and high rank of coals, and had littleeffect on that from middle rank of coals. The mechanical behaviors of cokes charred from different rank of coals and coal tar pitch were also different. The cokes from low rank of coals hadhigh mechanical strength because of obviously dissolution; the cokes from middle rank of coalshad little effect with pitch; however, the pitch obviously improves the mechanical capacities andthermal properties of the coke charred from high rank of coals.中国煤化工KEY WORDS coal tar pitch, rank of coal, thermal proper|,MHCNMH G.