Effect of CaO content on the ash fusibility of high sodium coal

WANG Dong-xu; QI Chao; WANG Yang; LI Wen-yan; XIAO Hai-ping; KANG Zhi-zhong

Volume 45 Issue 9

Sep. 2017

Turn off MathJax

Article Contents

Article Navigation > Journal of Fuel Chemistry and Technology > 2017 > 45(9): 1025-1034

WANG Dong-xu, QI Chao, WANG Yang, LI Wen-yan, XIAO Hai-ping, KANG Zhi-zhong. Effect of CaO content on the ash fusibility of high sodium coal[J]. Journal of Fuel Chemistry and Technology, 2017, 45(9): 1025-1034.

Citation:

WANG Dong-xu, QI Chao, WANG Yang, LI Wen-yan, XIAO Hai-ping, KANG Zhi-zhong. Effect of CaO content on the ash fusibility of high sodium coal[J]. Journal of Fuel Chemistry and Technology, 2017, 45(9): 1025-1034.

Citation:

PDF( 5604 KB)

Effect of CaO content on the ash fusibility of high sodium coal

1.
School of Energy, Power and Mechanical Engineering, North China Electric Power University, Beijing 102206, China
2.
National Engineering Laboratory for Biomass Power Generation Equipment, North China Electric Power University, Beijing 102206, China

Funds:

National Key Technology Research and Development Program of the Ministry of Science and Technology of China 2015BAA04B02

More Information

Corresponding author: LI Wen-yan, E-mail:liweny@126.com
Received Date: 2017-04-20
Rev Recd Date: 2017-06-23

Available Online: 2021-01-23

Publish Date: 2017-09-10

Abstract

Abstract

In order to study effect of CaO content on the ash fusibility of high sodium coal, high sodium synthetic coal ash samples with different CaO content were prepared and ash fusion temperatures (AFTs) were measured. Thermodynamic database FactSage 7.0 was applied to simulate the ash melting process, and the mineral conversion was analyzed. The minerals' composition and surface morphology of synthetic coal ash samples were investigated by X-ray diffraction (XRD) and scanning electronic microscope (SEM). The results show that the AFTs drop first and rise later with the increase of CaO content. CaO addition influences the existence form and relative mass of both calcium-containing and sodium-containing minerals. At 1 000℃, the calcium-containing minerals transform from anorthite to andradite, wollastonite, gehlenite, rankinite and larnite in turn. The sodium-containing minerals transform from albite to nepheline. The results of binary phase diagram and analogous ternary phase diagram indicate that variation of liquidus temperature is consistent with the AFTs with increasing CaO content. When the CaO content is higher than 40%, the AFTs could be improved efficiently for the coal sample.
- ash fusibility,
- high sodium coal,
- CaO content,
- thermodynamic simulation,
- mineral conversion

FullText(HTML)

References(19)

References

[1]	WANG X B, XU Z X, WEI B, ZHANG L, TAN H Z, YANG T, MIKULCIC H, DUIC N. The ash deposition mechanism in boilers burning Zhundong coal with high contents of sodium and calcium:A study from ash evaporating to condensing[J]. Appl Therm Eng, 2015, 80:150-159. doi: 10.1016/j.applthermaleng.2015.01.051
[2]	陶玉洁, 张彦威, 周俊虎, 景雪晖, 李涛, 刘建忠, 岑可法.准东煤在燃烧过程中的矿物演变过程及Na、Ca释放规律[J].中国电机工程学报, 2015, 35(5):1169-1175. http://www.cnki.com.cn/Article/CJFDTOTAL-ZGDC201505018.htm TAO Yu-jie, ZHANG Yan-wei, ZHOU Jun-hu, JING Xue-hui, LI Tao, LIU Jian-zhong, CEN Ke-fa. Mineral conversion regularity and release behavior of Na, Ca during Zhundong coal's combustion[J]. Proc CSEE, 2015, 35(5):1169-1175. http://www.cnki.com.cn/Article/CJFDTOTAL-ZGDC201505018.htm
[3]	张守玉, 陈川, 施大钟, 吕俊复, 王健, 郭熙, 董爱霞, 熊绍武.高钠煤燃烧利用现状[J].中国电机工程学报, 2013, 33(5):1-12. http://www.cnki.com.cn/Article/CJFDTOTAL-ZGDC201305001.htm ZHANG Shou-yu, CHEN Chuan, SHI Da-zhong, LÜ Jun-fu, WANG Jian, GUO Xi, DONG Ai-xia, XIONG Shao-wu. Situation of combustion utilization of high sodium coal[J]. Proc CSEE, 2013, 33(5):1-12. http://www.cnki.com.cn/Article/CJFDTOTAL-ZGDC201305001.htm
[4]	刘家利, 苏国庆, 张小宏, 杨忠灿, 姚伟.高碱金属煤煤灰沾污特性评价方法[J].热力发电, 2016(1):9-13. http://www.cnki.com.cn/Article/CJFDTOTAL-RLFD201601003.htm LIU Jia-li, SU Guo-qing, ZHANG Xiao-hong, YANG Zhong-can, YAO Wei. Evaluation method for ash fouling characteristics of coals with high alkali content[J]. Therm Power Gen, 2016(1):9-13) http://www.cnki.com.cn/Article/CJFDTOTAL-RLFD201601003.htm
[5]	XU J Y, YU D X, FAN B, ZENG X P, LÜ W Z, CHEN J. Characterization of Ash Particles from Co-combustion with a Zhundong Coal for Understanding Ash Deposition Behavior[J]. Energy Fuels, 2014, 28(1):678-684. doi: 10.1021/ef401545d
[6]	王洋, 李慧, 王东旭, 董长青, 陆强, 李文艳.煤灰熔融特性与灰成分之间关系的矿物变化研究[J].燃料化学学报, 2016, 44(9):1034-1042. http://rlhxxb.sxicc.ac.cn/CN/abstract/abstract18890.shtml WANG Yang, LI Hui, WANG Dong-xu, DONG Chang-qing, LU Qiang, LI Wen-yan. Relationship between coal ash fusibility and ash composition in terms of mineral changes[J]. J Fuel Chem Technol, 2016, 44(9):1034-1042. http://rlhxxb.sxicc.ac.cn/CN/abstract/abstract18890.shtml
[7]	WANG Y, XIANG Y, WANG D X, DONG C Q, YANG Y P, XIAO X B, LU Q, ZHAO Y, et al. Effect of Sodium Oxides in Ash Composition on Ash Fusibility[J]. Energy Fuels, 2016, 30(2):1437-1444. doi: 10.1021/acs.energyfuels.5b02722
[8]	SONG W J, TANG L H, ZHU X D, WU Y Q, ZHU Z B, KOYAMA S. Effect of Coal Ash Composition on Ash Fusion Temperatures[J]. Energy Fuels, 2009, 24(1):182-189.
[9]	LIU B, HE Q H, JIANG Z H, XU R F, HU B X. Relationship between coal ash composition and ash fusion temperatures[J]. Fuel, 2013, 105:293-300. doi: 10.1016/j.fuel.2012.06.046
[10]	孔令学, 白进, 李文, 白宗庆, 郭振兴.氧化钙含量对灰渣流体性质影响的研究[J].燃料化学学报, 2011, 39(6):407-412. http://rlhxxb.sxicc.ac.cn/CN/abstract/abstract17750.shtml KONG Ling-xue, BAI Jin, LI Wen, BAI Zong-qing, GUO Zhen-xing. Effect of lime addition on slag fluidity of coal ash[J]. J Fuel Chem Technol, 2011, 39(6):407-412. http://rlhxxb.sxicc.ac.cn/CN/abstract/abstract17750.shtml
[11]	陈晓东, 孔令学, 白进, 白宗庆, 李文.高温气化条件下Na₂O对煤灰中矿物质演化行为的影响[J].燃料化学学报, 2016, 44(3):263-272. http://rlhxxb.sxicc.ac.cn/CN/abstract/abstract18789.shtml CHEN Xiao-dong, KONG Ling-xue, BAI Jin, BAI Zong-qing, LI Wen. Effect of Na₂O on mineral transformation of coal ash under high temperature gasification condition[J]. J Fuel Chem Technol, 2016, 44(3):263-272. http://rlhxxb.sxicc.ac.cn/CN/abstract/abstract18789.shtml
[12]	YAN T G, BAI J, KONG L X, BAI Z Q, LI W, XU J. Effect of SiO₂/Al₂O₃ on fusion behavior of coal ash at high temperature[J]. Fuel, 2017, 193:275-283. doi: 10.1016/j.fuel.2016.12.073
[13]	李瑞连, 杜梅芳, 乌晓江, 许鲁霞, 张忠孝.高岭土对准东高碱煤煤灰熔融特性影响的量子化学与实验研究[J].燃料化学学报, 2016, 44(5):513-520. http://rlhxxb.sxicc.ac.cn/CN/abstract/abstract18822.shtml LI Rui-lian, DU Mei-fang, WU Xiao-jiang, XU Lu-xia, ZHANG Zhong-xiao. Effect of kaolin on the ash fusion characteristics of high alkali Zhundong coal:A quantum chemistry and experimental study[J]. J Fuel Chem Technol, 2016, 44(5):513-520. http://rlhxxb.sxicc.ac.cn/CN/abstract/abstract18822.shtml
[14]	陈凡敏, 王嘉瑞, 赵冰, 李小江, 覃涛.煤中矿物质对灰熔融和燃烧特性的影响[J].燃料化学学报, 2015, 43(1):27-33. http://rlhxxb.sxicc.ac.cn/CN/abstract/abstract18551.shtml CHEN Fan-min, WANG Jia-rui, ZHAO Bing, LI Xiao-jiang, QIN Tao. Effect of mineral form in coal on combustion characteristics and fusibility of coal ash[J]. J Fuel Chem Technol, 2015, 43(1):27-33. http://rlhxxb.sxicc.ac.cn/CN/abstract/abstract18551.shtml
[15]	VASSILEV S V, KITANO K, TAKEDA S, TSURUE T. Influence of mineral and chemical composition of coal ashes on their fusibility[J]. Fuel Process Technol, 1995, 45(1):27-51. doi: 10.1016/0378-3820(95)00032-3
[16]	马岩, 黄镇宇, 唐慧儒, 王智化, 周俊虎, 岑可法.准东煤灰化过程中的矿物演变及矿物添加剂对其灰熔融特性的影响[J].燃料化学学报, 2014, 42(1):20-25. http://rlhxxb.sxicc.ac.cn/CN/abstract/abstract18327.shtml MA Yan, HUANG Zhen-yu, TANG Hui-ru, WANG Zhi-hua, ZHOU Jun-hu, CEN Ke-fa. Mineral conversion of Zhundong coal during ashing process and the effect of mineral additives on its ash fusion characteristics[J]. J Fuel Chem Technol, 2014, 42(1):20-25. http://rlhxxb.sxicc.ac.cn/CN/abstract/abstract18327.shtml
[17]	李帆, 邱建荣, 郑楚光.煤中矿物质对灰熔融温度影响的三元相图分析[J].华中理工大学学报, 1996, 24(10):96-99. http://www.cnki.com.cn/Article/CJFDTOTAL-HZLG610.035.htm LI Fan, QIU Jian-rong, ZHENG Chu-guang. The effect of mineral matter in coal on the ash melting point with ternary phase diagram[J]. J Huazhong Univ Sci Technol, 1996, 24(10):96-99. http://www.cnki.com.cn/Article/CJFDTOTAL-HZLG610.035.htm
[18]	AKIYAMA K, PAK H, TAKUBO Y, TADA T, UEKI Y, YOSHⅡE R, NARUSE I. Ash deposition behavior of upgraded brown coal in pulverized coal combustion boiler[J]. Fuel Process Technol, 2011, 92(7):1355-1361. doi: 10.1016/j.fuproc.2011.02.016
[19]	AKIYAMA K, PAK H, UEKI Y, YOSHⅡE R, NARUSE I. Effect of MgO addition to upgraded brown coal on ash-deposition behavior during combustion[J]. Fuel, 2011, 90(11):3230-3236. doi: 10.1016/j.fuel.2011.06.041