Measurement of alkali content in Zhundong coal after chemical fractionation treatment by LIBS method
-
摘要: 为了评价水洗、醋酸铵洗和盐酸洗等化学处理方法去除准东煤中碱金属的能力，分析激光诱导击穿光谱（LIBS）技术快速测量煤中碱金属含量的可行性和准确性，采用去离子水、醋酸铵溶液和稀盐酸溶液依次对准东煤进行化学处理，并利用LIBS技术对各样本中的Na，K元素进行测量，同时与电感耦合等离子光谱（ICP）检测结果进行对比，得到了验证LIBS技术测量准东煤中碱金属含量可靠性的实验数据。结果表明，水洗等化学处理可高效地去除准东煤中的碱金属，而LIBS技术对不同样本中的Na，K元素测量重复性较好，并且具有较高的灵敏度和较低的检测极限，LIBS检测结果与ICP的相对误差不超过7%。该结果说明LIBS可作为在线测量煤样中碱金属含量的一种有效手段。Abstract: In order to evaluate the ability of chemical fractionation treatments, including water (H2O) washing, ammonium acetate washing (NH4Ac) and hydrochloric acid (HCl) washing, for the removal of alkali metal, and analyze the feasibility and accuracy of laser induced breakdown spectroscopy (LIBS) measuring the alkali content in coal, a sequence of solutions including deionized water, ammonium acetate and hydrochloric acid were employed to treat Zhundong coal. The contents of sodium and potassium in treated coal were measured by LIBS and compared with the measurements of inductively coupled plasma (ICP) spectroscopy. The experimental results of confirming the ability of LIBS in measuring the alkali content in coal were obtained.The results show chemical treatment such as washing can effectively remove the alkali metal from Zhundong coal, and LIBS technique has good repeatability of Na, K measurement for different samples. The measurements of Na and K by LIBS had high sensitivity and low detection limit. The relative error between LIBS and ICP was less than 7%. LIBS could be a valid method to achieve the online measurement of alkali metal in coal.
-
-
Table 1 Calibration solution and calibration sample
sample calibration solution/(μg·mL-1) calibration sample/(μg·g-1) Na K Na K basal sample 0 0 0 0 sample 1 50 10 500 100 sample 2 100 20 1000 200 sample 3 150 30 1500 300 sample 4 200 40 2000 400 
下载: 导出CSV
Table 2 Comparisons between LIBS and ICP measurement on Na and K derived from water washing, NH4Ac washing and HCl washing samples
sample Na concentration K concentration LIBS/(μg·g-1) ICP/(μg·g-1) relative error/% LIBS/(μg·g-1) ICP/(μg·g-1) relative error/% basal coal 2466.53 2445.00 0.87 482.39 477.00 1.12 H2O washing 1min 1370.78 1406.00 2.57 445.03 435.79 2.08 H2O washing 5min 1320.81 1300.00 1.58 446.00 421.17 5.57 H2O washing 15min 1284.17 1263.00 1.65 433.50 419.02 3.34 H2O washing 30min 1203.82 1249.00 3.75 415.28 415.75 0.11 H2O washing 60min 1192.72 1255.00 5.22 421.49 409.96 2.74 H2O washing 180min 1143.72 1221.00 6.76 416.27 404.47 2.84 NH4Ac washing 1min 775.47 767.50 1.03 393.54 379.10 3.67 NH4Ac washing 5min 797.08 779.30 2.23 382.00 382.64 0.17 NH4Ac washing 15min 750.80 751.60 0.11 376.41 378.65 0.59 NH4Ac washing 30min 762.83 772.10 1.22 381.28 383.38 0.55 NH4Ac washing 60min 764.57 761.70 0.38 387.50 377.90 2.48 NH4Ac washing 180min 775.94 787.20 1.45 379.31 382.89 0.94 HCl washing 1min 650.72 638.34 1.90 366.81 351.04 4.30 HCl washing 5min 663.94 652.35 1.75 371.06 351.17 5.36 HCl washing 15min 654.94 636.23 2.86 365.10 350.66 3.96 HCl washing 30min 644.30 650.39 0.95 353.56 351.51 0.58 HCl washing 60min 622.00 640.42 2.96 357.32 351.48 1.63 HCl washing 180min 634.53 646.79 1.93 360.70 351.79 2.47
下载: 导出CSV
-
[1] YANG Zh C, LIU J L, HE H G. Study on properties of Zhundong coal in Xinjiang region and type-selection for boilers burning this coal sort[J]. Thermal Power Generation, 2010, 39(8):38-40(in Chinese). http://en.cnki.com.cn/Article_en/CJFDTOTAL-RLFD201008013.htm
[2] ZHANG J, HAN Ch L, YAN Zh, et al. The varying characterization of alkali metals (Na, K) from coal during the initial stage of coal combustion[J]. Energy & Fuels, 2001, 15(4):786-793. DOI: 10.1021/ef000140u
[3] LIU J, WANG Zh H, XIANG F P, et al.Modes of occurrence and transformation of alkali metals in Zhundong coal during combustion[J]. Journal of Fuel Chemistry and Technology, 2014, 42(3):316-322(in Chinese). http://www.cqvip.com/QK/90650X/201403/49143973.html
[4] CHEN Ch, ZHANG Sh Y, LIU D H, et al.Existence form of sodium in high sodium coals from Xinjiang and its effect on combustion process[J]. Journal of Fuel Chemistry and Technology, 2013, 41(7):832-838(in Chinese). http://en.cnki.com.cn/Article_en/CJFDTOTAL-RLHX201307010.htm
[5] YU Ch J, TANG Y L, FANG M X, et al. Experimental study on alkali emission during rice straw pyrolysis[J]. Journal of Zhejiang University (Engineering Science Edition), 2005, 39(9):1435-1444(in Chinese). http://www.cqvip.com/Main/Detail.aspx?id=20219596
[6] YAO Sh Ch, LU J D, XIE Ch L, et al. Quantitative analysis of laser induced carbon plasma by intensity ratio calibration[J]. High Power Laser and Particle Beams, 2008, 20(7):1089-1092(in Chinese). http://www.en.cnki.com.cn/Article_en/CJFDTOTAL-QJGY200807007.htm
[7] ZHENG J P, LU J D, YAO Sh Ch, et al. Application review on laser-induced breakdown spectroscopy technology in coal analysis[J]. Guangdong Electric Power, 2012, 25(10):13-21(in Chinese).
[8] YU L Y, LU J D, CHEN W, et al. Analysis of pulverized coal by laser-induced breakdown spectroscopy[J]. Plasma Science & Technology, 2005, 7(5):3041-3044. http://d.wanfangdata.com.cn/Periodical/dlztkxyjs-e200505015
[9] LI J, LU J, LIN Z, et al. Effects of experimental parameters on elemental analysis of coal by laser-induced breakdown spectroscopy[J]. Optics & Laser Technology, 2009, 41(8):907-913. http://www.sciencedirect.com/science/article/pii/S0030399209000334
[10] FENG J, WANG Z, WEST L, et al. A PLS model based on dominant factor for coal analysis using laser-induced breakdown spectroscopy[J]. Analytical and Bioanalytical Chemistry, 2011, 400(10):3261-3271. DOI: 10.1007/s00216-011-4865-y
[11] HE Y, QIU K Z, WHIDDON R, et al. Release characteristic of different classes of sodium during combustion of Zhundong coal investigated by laser-induced breakdown spectroscopy[J]. Science Bulletin, 2015, 60(22):1927-1934. DOI: 10.1007/s11434-015-0922-9
[12] HE Y, ZHU J J, LI B, et al. In-situ measurement of sodium and potassium release during oxy-fuel combustion of lignite using laser-induced breakdown spectroscopy:effects of O2 and CO2 concentration[J]. Energy & Fuels, 2013, 27(2):1123-1130. DOI: 10.1021/ef301750h
[13] BENSON S A, HOLM P L.Comparison of inorganics in three low-rank coals[J]. Industrial & Engineering Chemistry Product Research and Development, 1985, 24(1):145-149. DOI: 10.1021/i300017a027
[14] BODY D, CHADWICK B L. Optimization of the spectral data processing in a LIBS simultaneous elemental analysis system[J]. Spectrochimica Acta Part B:Atomic Spectroscopy, 2001, 56(6):725-736. DOI: 10.1016/S0584-8547(01)00186-0
[15] FENG J. Study to improve the accuracy of LIBS measurement and the application to coal analysis[D]. Beijing: Tsinghua University, 2011: 22-25(in Chinese).
[16] WANG Zh H, ZHU Zh B. Microscopic laser emission spectrum quantitative analysis on the fundamental formula[J]. Rock and Mineral Analysis, 1989, 2(9):149-151(in Chinese).
计量
- 文章访问数: 9
- HTML全文浏览量: 1
- PDF下载量: 5