煤矸石灰添加对准东煤灰熔融特性影响
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摘要
选取两种准东煤(ZDA和ZDB)为研究对象,利用灰熔融温度测定仪、X射线荧光光谱和X射线衍射仪考察了单一准东煤灰及其与煤矸石(CG)灰掺混后酸碱比、化学组成和矿物质演变对灰熔融特征温度的影响规律。结果表明高温下ZDA中主要矿物组分为霓辉石和赤铁矿等助熔矿物,而ZDB中以难熔矿物硫铝酸钙与镁硅钙石为主,导致ZDA灰熔融温度明显低于ZDB。随着CG灰质量分数增加,ZDA/CG与ZDB/CG熔融特征温度呈现先下降后上升趋势,分别在CG灰添加比40%和60%时出现最小值;当ZDA/CG与ZDB/CG酸碱比接近时,CaO与Fe_2O_3含量是影响变形温度与流动温度的主要原因。对于上述两种高碱性煤灰,含钙矿物对于灰熔融特性影响较大,而含钠矿物的影响相对较小。本文旨在为改善准东煤灰沉积倾向提供基础数据。
The fusibility of two types of Zhundong coal(ZDA and ZDB) ashes and the mixtures with coal gangue(CG) ash was studied by ash fusion test using X-ray diffractometry and X-ray spectrometry. The effect of acid to basic ratio, ash chemistry and mineral transformation on ash fusion temperatures(AFTs)was investigated for both individual and blending ash samples. The results showed that the ash fusion temperature of ZDA was obviously lower than that of ZDB due to more fluxing minerals including augite and hematite in ZDA ash, whilst refractory minerals including yeelinmite and merwinite in the ZDB ash.The AFTs of both blending ashes decreasd first and then increased with the increase in ZDA/CG or ZDB/CG ash ratio. The minimum AFTs were observed with the CG ash ratios of 40% and 60%, respectively.The deformation temperature and flow temperature were mainly attributed to the difference of CaO and Fe_2 O_3 weight ratio, as the acid to basic ratio of ZDA/CG was similar to that of ZDB/CG. Compared to the sodium-containing minerals, the calcium-containing minerals play a more important role in the ash fusion characteristics for the high-alkali coal ash. Furthermore, the basic data was obtained for improving ash deposition behavior of Zhundong coal ash in this study.
The fusibility of two types of Zhundong coal(ZDA and ZDB) ashes and the mixtures with coal gangue(CG) ash was studied by ash fusion test using X-ray diffractometry and X-ray spectrometry. The effect of acid to basic ratio, ash chemistry and mineral transformation on ash fusion temperatures(AFTs)was investigated for both individual and blending ash samples. The results showed that the ash fusion temperature of ZDA was obviously lower than that of ZDB due to more fluxing minerals including augite and hematite in ZDA ash, whilst refractory minerals including yeelinmite and merwinite in the ZDB ash.The AFTs of both blending ashes decreasd first and then increased with the increase in ZDA/CG or ZDB/CG ash ratio. The minimum AFTs were observed with the CG ash ratios of 40% and 60%, respectively.The deformation temperature and flow temperature were mainly attributed to the difference of CaO and Fe_2 O_3 weight ratio, as the acid to basic ratio of ZDA/CG was similar to that of ZDB/CG. Compared to the sodium-containing minerals, the calcium-containing minerals play a more important role in the ash fusion characteristics for the high-alkali coal ash. Furthermore, the basic data was obtained for improving ash deposition behavior of Zhundong coal ash in this study.
引文
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[14]沈铭科,邱坤赞,黄镇宇,等.准东煤掺烧高岭土对固钠率及灰熔融特性影响研究[J].燃料化学学报, 2015, 43(9):1045-1051.SHEN M K, QIU K Z, HUANG Z Y, et al. Influence of kaolin on sodium retention and ash fusion characteristic during combustion of Zhundong coal[J]. Journal of Fuel Chemistry and Technology, 2015, 43(9):1045-1051.
[15]张利孟,董信光,刘摇科,等.高岭土对准东煤结渣特性及矿物质演变的影响[J].燃料化学学报, 2015, 43(10):1176-1181.ZHANG L M, DONG X G, LIU Y K, et al. Effect of kaolin on ash slagging and mineral conversion of Zhundong coal[J]. Journal of Fuel Chemistry and Technology, 2015, 43(10):1176-1181.
[16]付子文,王长安,车得福,等.成灰温度对准东煤灰理化特性影响的实验研究[J].工程热物理学报, 2014, 35(3):609-613.FU Z W, WANG C A, CHE D F, et al. Experimental study on the effect of ashing temperature on physicochemical properties of Zhundong coal ashes[J]. Journal of Engineering Thermophysics, 2014, 35(3):609-613.
[17] RAASK E. Mineral Impurities in coal combustion:behavior, problems,and remedial measures[M]. USA:DOE, 1985.
[18]徐荣声,王永刚,林雄超,等.配煤和助熔剂降低煤灰熔融温度的矿物学特性研究[J].燃料化学学报, 2015, 43(11):1303-1310.XU R S, WANG Y A, LIN X C, et al. Mineralogical properties of lowering coal ash melting temperature using blending coal and fluxing agent[J]. Journal of Fuel Chemistry and Technology, 2015, 43(11):1303-1310.
[19] CHEN X D, KONG L X, BAI J, et al. Study on fusibility of coal ash rich in sodium and sulfur by synthetic ash under different atmosphere[J]. Fuel, 2017, 202:175-183.
[20]张龙,黄镇宇,沈铭科,等.不同的灰熔点调控方式对煤灰熔融特性的影响[J].燃料化学学报, 2015, 43(2):145-152.ZHANG L, HUANG Z Y, SHEN M K, et al. Effect of different regulative methods on coal ash fusion characteristics[J]. Journal of Fuel Chemistry and Technology, 2015, 43(2):145-152.
[21] JING J, WANG Q H, LUO Z Y, et al. Effect of different reaction atmospheres on the sintering temperature of Jincheng coal ash under pressurized conditions[J]. Fuel, 2011, 90:2645-2651.
[2]张守玉,陈川,施大钟,等.高钠煤燃烧利用现状[J].中国电机工程学报, 2013, 33(5):1-12.ZHANG S Y, CHEN C, SHI D Z, et al. Situation of combustion utilization of high sodium coal[J]. Proceedings of the CSEE, 2013, 33(5):1-12.
[3] LI J B, ZhU M M, ZHANG Z Z, et al. Characterisation of ash deposits on a probe at different temperatures during combustion of a Zhundong lignite in a drop tube furnace[J]. Fuel Processing Technology, 2016,144:155-163.
[4] QI X B, SONG G L, SONG W J, et al. Influence of sodium-based materials on the slagging characteristics of Zhundong coal[J]. Journal of the Energy Institute, 2017, 90:914-922.
[5] LUAN C, YOU C F, ZHANG D K. Composition and sintering characteristics of ashes from co-firing of coal and biomass in a laboratory-scale drop tube furnace[J]. Energy, 2014, 69:562-570.
[6] WILLENBORG W, MULLER M, HILPERTK K. Alkali removal at about 1400℃for the pressurized pulverized coal combustion combined cycle. 1. Thermodynamics and concept[J]. Energy&Fuels, 2006, 20(6):2593-2598.
[7] TRAN K Q, IISA K, STEENARI B M, et al. A kinetic study of gaseous alkali capture by kaolin in the fixed bed reactor equipped with an alkali detector[J]. Fuel, 2005, 84:169-175.
[8] VUTHALURUA H B, FRENCH D. Ash chemistry and mineralogy of an Indonesian coal during combustion. Part 1:Drop-tube observations[J]. Fuel Processing Technology, 2008, 89:595-607.
[9] DAI B Q, WU X J, GIROLAMO A D, et al. Inhibition of lignite ash slagging and fouling upon the use of a silica-based additive in an industrial pulverised coal-fired boiler. Part 1:Changes on the properties of ash deposits along the furnace[J]. Fuel, 2015, 139:720-732.
[10] WANG L H, ZHAO P D, LI G. Character of Si and Al phases in coal gangue and its ash[J]. Acta Geologica Sinica, 2009, 83(6):1116-1121.
[11] VASSILEV S V, KITANO K, TAKEDAB S, et al. Influence of mineral and chemical composition of coal ashes on their fusibility[J]. Fuel Processing Technology, 1995(45):27-51.
[12] NIU Y Q, WANG Z Z, ZHU Y M, et al. Experimental evaluation of additives and K2O–SiO2–Al2O3diagrams on high-temperature silicate melt-induced slagging during biomass combustion[J]. Fuel,2016, 179:52-59.
[13] LIU B, HE Q H, JIANG Z H, et al. Relationship between coal ash composition and ash fusion temperatures[J]. Fuel, 2013, 105:293-300.
[14]沈铭科,邱坤赞,黄镇宇,等.准东煤掺烧高岭土对固钠率及灰熔融特性影响研究[J].燃料化学学报, 2015, 43(9):1045-1051.SHEN M K, QIU K Z, HUANG Z Y, et al. Influence of kaolin on sodium retention and ash fusion characteristic during combustion of Zhundong coal[J]. Journal of Fuel Chemistry and Technology, 2015, 43(9):1045-1051.
[15]张利孟,董信光,刘摇科,等.高岭土对准东煤结渣特性及矿物质演变的影响[J].燃料化学学报, 2015, 43(10):1176-1181.ZHANG L M, DONG X G, LIU Y K, et al. Effect of kaolin on ash slagging and mineral conversion of Zhundong coal[J]. Journal of Fuel Chemistry and Technology, 2015, 43(10):1176-1181.
[16]付子文,王长安,车得福,等.成灰温度对准东煤灰理化特性影响的实验研究[J].工程热物理学报, 2014, 35(3):609-613.FU Z W, WANG C A, CHE D F, et al. Experimental study on the effect of ashing temperature on physicochemical properties of Zhundong coal ashes[J]. Journal of Engineering Thermophysics, 2014, 35(3):609-613.
[17] RAASK E. Mineral Impurities in coal combustion:behavior, problems,and remedial measures[M]. USA:DOE, 1985.
[18]徐荣声,王永刚,林雄超,等.配煤和助熔剂降低煤灰熔融温度的矿物学特性研究[J].燃料化学学报, 2015, 43(11):1303-1310.XU R S, WANG Y A, LIN X C, et al. Mineralogical properties of lowering coal ash melting temperature using blending coal and fluxing agent[J]. Journal of Fuel Chemistry and Technology, 2015, 43(11):1303-1310.
[19] CHEN X D, KONG L X, BAI J, et al. Study on fusibility of coal ash rich in sodium and sulfur by synthetic ash under different atmosphere[J]. Fuel, 2017, 202:175-183.
[20]张龙,黄镇宇,沈铭科,等.不同的灰熔点调控方式对煤灰熔融特性的影响[J].燃料化学学报, 2015, 43(2):145-152.ZHANG L, HUANG Z Y, SHEN M K, et al. Effect of different regulative methods on coal ash fusion characteristics[J]. Journal of Fuel Chemistry and Technology, 2015, 43(2):145-152.
[21] JING J, WANG Q H, LUO Z Y, et al. Effect of different reaction atmospheres on the sintering temperature of Jincheng coal ash under pressurized conditions[J]. Fuel, 2011, 90:2645-2651.