Ca种类对准东煤灰烧结特性影响

doi:10.11949/0438-1157.20250103

摘要/Abstract

摘要：

以准东五彩湾高碱煤（WCW）为实验对象及模型进行合成灰配比，选用SiO₂、Al₂O₃、Fe₂O₃、Na₂CO₃和CaCO₃/CaSO₄为原料进行合成灰制备。对样品进行燃烧实验，对所得灰样进行筛分、XRD和FTIR检测，以探究不同钙对高碱煤灰烧结特性的影响。结果表明，使用CaCO₃制备的合成灰（RR-1-Cal）初始烧结温度低于使用CaSO₄制备的合成灰（RR-1-An），RR-1-An烧结倾向强于RR-1-Cal。灰中CaCO₃对液相烧结的影响路径是因为Na-Si-Al之间反应生成钠长石，CaO与Si/Al反应生成含钙硅铝酸盐后，钠长石与含钙硅铝酸盐发生低温共熔。除此之外，硫酸根的加入会使得硅铝结构在高温下更不稳定，更易出现熔融烧结现象。在固相烧结过程中，CaCO₃对煤灰硅结构先破坏后聚合，CaSO₄则促进煤灰在更低温度下发生聚合。

关键词: 煤燃烧, 烧结, 反应, 聚合

Abstract:

In this study, the Wucaiwan high-alkali coal (WCW) from Zhundong was used as the raw material. SiO₂, Al₂O₃, Fe₂O₃, Na₂CO₃ and CaCO₃/CaSO₄ were used to prepare the synthetic ash. The samples were burned in the furnace. The ashes after burning were screened and analyzed by XRD and FTIR to explore the influence of calcium species on the sintering characteristics of high-alkali coal ash. The results show that the initial sintering temperature of the synthetic ash prepared by CaCO₃ (RR-1-Cal) is lower than that of prepared by CaSO₄ (RR-1-An), but the sintering tendency of RR-1-An is stronger than that of RR-1-Cal. The influence of CaCO₃ in ash on liquid phase sintering is because Na-Si-Al reacts to form albite, and after CaO reacts with Si/Al to form calcium-containing aluminosilicate, albite and calcium-containing aluminosilicate undergo low-temperature eutectic. Without the low-temperature eutectic between calcium aluminosilicates and albite, CaSO₄ contained in the ash add the sulfate radicals into the reaction, which make the silicon-aluminum structure more unstable at high temperatures and leads to the melting and sintering phenomenon easier to occur. During the solid-phase sintering process, CaCO₃ first destroys and then polymerizes the silicon structure of coal ash, while CaSO₄ promotes the polymerization of coal ash at lower temperatures.

Key words: coal combustion, sintering, reaction, polymerization

中图分类号:

TK 16

黄小河, 张守玉. Ca种类对准东煤灰烧结特性影响[J]. 化工学报, 2025, 76(9): 4913-4921.

Xiaohe HUANG, Shouyu ZHANG. Effect of Ca species on sintering characteristics of Zhundong coal ash[J]. CIESC Journal, 2025, 76(9): 4913-4921.

图/表 10

表1 五彩湾煤灰分分析

Table 1 Ash analysis of Wucaiwan coal

煤种	灰分分析/%
煤种	SiO₂	Al₂O₃	Fe₂O₃	CaO	MgO	TiO₂	SO₃	K₂O	Na₂O	P₂O₅
WCW	11.07	11.55	2.72	47.85	2.01	1.30	18.20	0.66	4.26	0.06

表2 不同钙种类合成灰样品编号及其配比

Table 2 Code and proportion of the synthetic ashes prepared by different calcium species

样品编号	钙种类	合成灰各组分比例/%
样品编号	钙种类	SiO₂	Al₂O₃	Fe₂O₃	Na₂CO₃	Ca*
RR-1-Cal	CaCO₃	9.98	9.98	2.38	6.48	71.18
RR-1-An	CaSO₄	7.93	7.93	1.98	5.15	77.01

图1 燃烧所得灰样烧结比

Fig. 1 Sintering ratio of the ashes after combustion

图2 不同钙种类合成灰经不同温度燃烧所得灰样XRD谱图A—钠长石 (NaAlSi3O8);An—硫酸钙 (CaSO4);Cal—碳酸钙 (CaCO3);CaS—硅酸钙 (Ca3SiO5);Ma—钙铝石 (Ca12Al14O33);Q—石英 (SiO2)

Fig.2 XRD patterns of synthetic ashes prepared by different calcium species after combustion at different temperature

表3 灰样中无机物的红外光谱吸收峰

Table 3 FTIR absorption peak of inorganic components in ash samples

波段/cm^-1	吸收峰	文献
1440~1480	碳酸盐	[29]
1432, 1425, 875, 867, 711, 717, 707	碳酸钙	[29]
1405	Al—O反对称伸长振动	[29]
1147, 674, 663, 613, 593	硫酸钙	[30]
1025	Si—O对称伸长振动	[30]
887	铝氧四面体AlO₄	[30]
850	Si—O振动	[31]
833	云母	[30]
817	Si—O—Si和Al—O对称伸缩振动	[32]
698	Si—O弯曲振动	[31]
651	碱性长石O—Si(Al)—O弯曲振动	[32-33]
636	碱性长石	[32]
570	Si—O延伸振动	[31]
536	Al—O—Si弯曲振动	[31]
501	Si—O(SiO₄)弯曲振动	[31]
485	变高岭石	[31, 33]
422	钠长石	[29, 31]
411, 404	云母 Si—O—Si变形振动	[31]

图3 不同钙种类合成灰经不同温度燃烧所得灰样FTIR谱图

Fig.3 FTIR spectra of synthetic ashes prepared by different calcium species after combustion at different temperature

图4 合成灰经不同温度燃烧所得灰样的二阶导数谱图

Fig.4 Second derivative spectra of synthetic ashes prepared by different calcium species after combustion at different temperature

图5 不同钙种类灰样Q n 结构单元面积比

Fig.5 Area ratio of Q n structural units of the synthetic ashes prepared by different calcium species

图6 SiO2中Q n 结构单元面积比

Fig.6 Area ratio of Q n structural units in SiO2

图7 灰样聚合度

Fig.7 Degree polymerization of synthetic ashes after combustion

参考文献 1

[2]	Song Y W, Chen Y F, Su S, et al. Effects of inorganic sodium on the combustion characteristics of Zhundong coal with fast-heating rate[J]. Fuel, 2022, 319: 123801.
[3]	Xiao R H, Wang Y, Zhang Y L, et al. Effect of kaolinite additive on water-soluble sodium release and particle matter formation during Zhundong coal combustion[J]. Fuel, 2023, 333: 126422.
[4]	Zhang L, Yan J C, Yang Q T, et al. Co-firing Zhundong coal with its gangue: combustion performance, sodium retention and ash fusion behaviors[J]. Sustainability, 2022, 14(24): 16451.
[5]	Zi J B, Ma D Y, Wang X B, et al. Slagging behavior and mechanism of high-sodium-chlorine coal combustion in a full-scale circulating fluidized bed boiler[J]. Journal of the Energy Institute, 2020, 93(6): 2264-2270.
[6]	Wang C A, Li G Y, Du Y B, et al. Ash deposition and sodium migration behaviors during combustion of Zhundong coals in a drop tube furnace[J]. Journal of the Energy Institute, 2018, 91(2): 251-261.
[7]	Wu X J, Zhang X, Dai B Q, et al. Ash deposition behaviours upon the combustion of low-rank coal blends in a 3 MW_th pilot-scale pulverised coal-fired furnace[J]. Fuel Processing Technology, 2016, 152: 176-182.
[8]	Song G L, Qi X B, Song W J, et al. Slagging behaviors of high alkali Zhundong coal during circulating fluidized bed gasification[J]. Fuel, 2016, 186: 140-149.
[9]	俞海淼, 曹欣玉, 张鹤声, 等. 若干典型煤灰样烧结熔融特性研究[J]. 同济大学学报(自然科学版), 2008, 36(5): 664-669.
	Yu H M, Cao X Y, Zhang H S, et al. Research on sintering and fusion characteristics of several representative coal ashes[J]. Journal of Tongji University (Natural Science), 2008, 36(5): 664-669.
[10]	Tang C W, Pan W G, Zhang J K, et al. A comprehensive review on efficient utilization methods of high-alkali coals combustion in boilers[J]. Fuel, 2022, 316: 123269.
[11]	李君杰. 富氧燃烧下高钙/高碱煤成灰及沉积特性研究[D]. 武汉: 华中科技大学, 2018.
	Li J J. Study on ash formation and deposition characteristics of high calcium/high alkali coal under oxygen-enriched combustion[D]. Wuhan: Huazhong University of Science and Technology, 2018.
[12]	卢啸风, 李建波, 刘卓, 等. 燃准东煤电站锅炉沾污结渣特性及防治措施研究进展[J]. 中国电机工程学报, 2024, 44(18): 7247-7264.
	Lu X F, Li J B, Liu Z, et al. Research progress on the characteristics and countermeasures of ash slagging and fouling in boilers burning Zhundong coal[J]. Proceedings of the CSEE, 2024, 44(18): 7247-7264.
[13]	Yuan Z S, Wang J, Kong L X, et al. Comparison study of fusibility between coal ash and synthetic ash[J]. Fuel Processing Technology, 2021, 211: 106593.
[14]	Zhang M R, Guo J W, Yao S Y, et al. The influence mechanism of ionic liquids on the ash melting and combustion characteristics of Zhundong high-alkali coal[J]. International Journal of Coal Preparation and Utilization, 2025, 45(1): 112-127.
[15]	Zhang X X, Huang L, Kong L X, et al. Effect of phosphorus-based additives on sodium release during Zhundong coal gasification in flat flame-assisted entrained flow reactor[J]. Combustion and Flame, 2023, 249: 112608.
[16]	Jung B, Schobert H H. Viscous sintering of coal ashes (1): Relationships of sinter point and sinter strength to particle size and composition[J]. Energy & Fuels, 1991, 5(4): 555-561.
[17]	Zbogar A, Frandsen F, Jensen P A, et al. Shedding of ash deposits[J]. Progress in Energy and Combustion Science, 2009, 35(1): 31-56.
[18]	张守玉, 徐梓航, 黄东东, 等. 氯化钠蒸气对高钠煤煤灰钠捕获性能及其烧结温度的影响[J]. 煤炭学报, 2023, 48(1): 452-459.
	Zhang S Y, Xu Z H, Huang D D, et al. Effect of NaCl vapor concentration on sodium-capturing performance and sintering temperature of coal ash[J]. Journal of China Coal Society, 2023, 48(1): 452-459.
[19]	Lei T, Zhao J R, Zhang Z H. In-situ ash sintering process analysis during the co-combustion of the coal gasification fine slag and corn straw[J]. Energy, 2024, 310: 133311.
[20]	Liu K P, Wei B, Wang J J, et al. Effect of atmosphere and chemical composition on ash fusion process of Zhundong high iron coal[J]. Fuel, 2025, 386: 134223.
[21]	Zhao C Y, Wang C, Men X Y, et al. In-situ study of the effect of potassium release on ash sintering behavior during the co-gasification of coal and biomass[J]. Journal of Industrial and Engineering Chemistry, 2024, 140: 364-375.
[22]	Yang H R, Jin J, Liu D Y, et al. The effect on ash deposition by blending high-calcium Zhundong coal with vermiculite: focusing on minerals transformations[J]. Asia-Pacific Journal of Chemical Engineering, 2021, 16(1): e2571.
[23]	Yang S B, Song G L, Na Y J, et al. Alkali metal transformation and ash deposition performance of high alkali content Zhundong coal and its gasification fly ash under circulating fluidized bed combustion[J]. Applied Thermal Engineering, 2018, 141: 29-41.
[24]	Yang S B, Song G L, Na Y J, et al. Transformation characteristics of Na and K in high alkali residual carbon during circulating fluidized bed combustion[J]. Journal of the Energy Institute, 2019, 92(1): 62-73.
[25]	Yang Y P, Lin X C, Chen X J, et al. The formation of deposits and their evolutionary characteristics during pressurized gasification of Zhundong coal char[J]. Fuel, 2018, 224: 469-480.
[26]	尹艳山, 尹杰, 张巍, 等. 红外和拉曼光谱的煤灰矿物组成研究[J]. 光谱学与光谱分析, 2018, 38(3): 789-793.
	Yin Y S, Yin J, Zhang W, et al. Characterization of mineral matter in coal ashes with infrared and Raman spectroscopy[J]. Spectroscopy and Spectral Analysis, 2018, 38(3): 789-793.
[27]	黄小河, 张守玉, 杨靖宁, 等. 准东煤高温燃烧过程中含钙矿物质的转化规律[J]. 化工学报, 2017, 68(10): 3906-3911.
	Huang X H, Zhang S Y, Yang J N, et al. Calcium transformation during Zhundong coal combustion process[J]. CIESC Journal, 2017, 68(10): 3906-3911.
[28]	Zhou H, Ma W C. An experimental study on the effects of adding biomass ashes on ash sintering behavior of Zhundong coal[J]. Applied Thermal Engineering, 2017, 126: 689-701.
[29]	Ionescu B A, Barbu A M, Lăzărescu A V, et al. The influence of substitution of fly ash with marble dust or blast furnace slag on the properties of the alkali-activated geopolymer paste[J]. Coatings, 2023, 13(2): 403.
[30]	Yin Y S, Yin J, Zhang W, et al. FT-IR and micro-Raman spectroscopic characterization of minerals in high-calcium coal ashes[J]. Journal of the Energy Institute, 2018, 91(3): 389-396.
[31]	Yang J J, Sun H J, Peng T J, et al. Study on the overall reaction pathways and structural transformations during decomposition of coal fly ash in the process of alkali-calcination[J]. Materials, 2021, 14(5): 1163.
[32]	Dakhane A. Multiscale engineering response of alkali activated aluminosilicate binders[D]. Phoenix Arizona State University, 2016.
[33]	Criado M, Fernández-Jiménez A, Palomo A. Alkali activation of fly ash: effect of the SiO₂/Na₂O ratio[J]. Microporous and Mesoporous Materials, 2007, 106(1/2/3): 180-191.
[34]	季杰强. 高碱煤燃烧碱金属钠迁移特性研究[D]. 杭州: 浙江大学, 2019.
	Ji J Q. Study on migration characteristics of alkali metal sodium in high alkali coal combustion[D]. Hangzhou: Zhejiang University, 2019.
[35]	Ge H J, Shen L H, Bai H C, et al. Characteristics of Zhundong coal ash in hematite-based chemical looping combustion[J]. Energy & Fuels, 2020, 34(7): 8150-8166.
[36]	Huang Z, Li N, Zhou Q L, et al. A comparative study of the pyrolysis and combustion characteristics of sodium-rich Zhundong coal in slow and rapid processes[J]. Energy Science & Engineering, 2019, 7(1): 98-107.
[37]	Fan H L, Li F H, Guo Q Q, et al. Effect of biomass ash on initial sintering and fusion characteristics of high melting coal ash[J]. Journal of the Energy Institute, 2021, 94: 129-138.
[38]	Bonafous L, Bessada C, Massiot D, et al. ²⁹Si MAS NMR study of dicalcium silicate: the structural influence of sulfate and alumina stabilizers[J]. Journal of the American Ceramic Society, 1995, 78(10): 2603-2608.
[39]	Zhang X X, Dou H Y, Bai J, et al. Effect of phosphorus on viscosity-temperature behavior of high-sodium coal ash slag[J]. Fuel, 2023, 343: 127930.
[40]	Liu Y X, Zeng F G, Sun B L, et al. Structural characterizations of aluminosilicates in two types of fly ash samples from Shanxi Province, North China[J]. Minerals, 2019, 9(6): 358.
[41]	Ma F R, Wei B, Wang J J, et al. Influence mechanism of Na₂O on the network structure depolymerization of ZD coal ash silicate under high temperature[J]. Journal of Non-Crystalline Solids, 2022, 584: 121507.
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	Ma D F, Zhang S Y, He X, et al. Experimental study on combustion optimization to alleviate fouling on heating surface of a Zhundong coal boiler[J]. Coal Science and Technology, 2023, 51(8): 304-312.