CaO含量对高钠煤灰熔融特性的影响

王东旭; 祁超; 王洋; 李文艳; 肖海平; 康志忠

CaO含量对高钠煤灰熔融特性的影响

1.
华北电力大学能源动力与机械工程学院, 北京 102206
2.
华北电力大学生物质发电成套设备国家工程实验室, 北京 102206

基金项目:

国家科技支撑计划项目 2015BAA04B02

详细信息

中图分类号: TQ536.4
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出版历程
- 收稿日期: 2017-04-20
- 修回日期: 2017-06-23
- 网络出版日期: 2021-01-23
- 刊出日期: 2017-09-10

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

摘要

摘要: 为研究CaO含量对高钠煤灰熔融特性的影响，配制了不同CaO含量的高钠合成灰并对灰熔融温度（AFTs）进行了测试，利用FactSage 7.0提供的热力学数据库对灰熔融过程进行了模拟，分析不同CaO含量的高钠合成灰的矿物质变化，利用X射线衍射（XRD）、扫描电子显微镜（SEM）对合成灰的矿物质组成及微观形貌进行了研究。结果表明，随着CaO含量的增加，灰熔融温度先降低后提高。添加CaO同时影响含钙矿物质与含钠矿物质的存在形式与相对含量。在1 000℃下，含钙矿物质由钙长石依次转化为钙铁榴石、硅灰石、钙黄长石、硅钙石和原硅酸钙，含钠矿物质由钠长石转化为霞石。二元相图和似三元相图的结果表明，液相线温度随CaO含量的变化趋势与灰熔融温度相同。对本研究中的煤种，当CaO含量高于40%时，可以有效提高灰熔融温度。
- 灰熔融特性 /
- 高钠煤 /
- CaO含量 /
- 热力学模拟 /
- 矿物变化
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

HTML全文

图 1 CaO含量对灰熔融温度的影响

Figure 1 Effect of CaO content on ash fusion temperatures

下载: 全尺寸图片幻灯片

图 2 1000℃下随CaO含量增加灰分中矿物质的变化

Figure 2 Mineral changes with the increasing content of CaO at 1000℃

(a): calcium-containing minerals; (b): other minerals

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图 3 不同CaO含量下随温度升高灰分中的矿物质变化

Figure 3 Mineral changes with the rising temperature under different CaO contents

(a): CaO 5%; (b): CaO 25%; (c): CaO 35%; (d): CaO 50%

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图 4 1000℃下不同CaO含量合成灰的XRD谱图

Figure 4 XRD patterns of synthetic ash with different CaO contents at 1000℃

a: CaO 5%; b: CaO 25%; c: CaO 35%; d: CaO 50% A:albite; Ad: andradite; An: anorthite; C: corundum; G: gehlenite; H: hematite; L: larnite; Li: lime; N: nepheline; S: srebrodolskite; W: wollastonite

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图 5 1100℃下不同CaO含量合成灰的XRD谱图

Figure 5 XRD patterns of synthetic ash with different CaO contents at 1100℃

a: CaO 5%; b: CaO 25%; c: CaO 35%; d: CaO 50% A: albite; Ad: andradite; An: anorthite; C: corundum; G: gehlenite; H: hematite; L: larnite; Li: lime; N: nepheline; R: rankinite; S: srebrodolskite; W: wollastonite

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图 6 1200℃下不同CaO含量合成灰的XRD谱图

Figure 6 XRD patterns of synthetic ash with different CaO contents at 1200℃

a: CaO 5%; b: CaO 25%; c: CaO 35%; d: CaO 50% An: anorthite; C: corundum; G: gehlenite; H: hematite; L: larnite; N: nepheline; R: rankinite

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图 7 SiO₂-Al₂O₃-CaO-Na₂O系统的二元相图

Figure 7 Binary phase diagram of SiO₂-Al₂O₃-CaO-Na₂O system

1: slag+Al₂O₃; 2: slag+Al₂O₃+CaAl₂Si₂O₈; 3: slag+CaAl₂Si₂O₈; 4: slag+CaAl₂Si₂O₈+CaAl₂SiO₇; 5: slag+CaAl₂SiO₇; 6: slag+Ca₂SiO₄+CaAl₂SiO₇; 7: slag+Ca₂SiO₄

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图 8 SiO₂-Al₂O₃-CaO-Na₂O系统的似三元相图

Figure 8 Analogous ternary phase diagram of SiO₂-Al₂O₃-CaO-Na₂O system

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图 9 不同CaO含量的合成灰的微观形态照片

(a): CaO 5%; (b): CaO 25%; (c): CaO 35%; (d): CaO 50%

Figure 9 Surface morphology of synthetic ash with different CaO contents

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图 10 不同CaO含量下随温度升高液相的变化

Figure 10 Slag changes with rising temperature under different CaO contents

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表 1 准东煤的灰成分分析

Table 1 Ash compositon of Zhundong coal

Content w/%
SiO₂	Al₂O₃	Fe₂O₃	CaO	MgO	Na₂O	K₂O	TiO₂	SO₃
35.95	14.60	16.32	11.72	5.69	4.46	0.78	0.96	9.10

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表 2 合成灰的灰成分分析

Table 2 Composition of synthetic ashes in experiments

Ash sample	Content of oxides w/%
Ash sample	SiO₂	Al₂O₃	S/A	Fe₂O₃	CaO	Na₂O
1	47.88	19.44	2.46	21.74	5.00	5.94
2	45.36	18.42	2.46	20.59	10.00	5.63
3	42.84	17.40	2.46	19.45	15.00	5.31
4	40.32	16.37	2.46	18.30	20.00	5.00
5	37.80	15.35	2.46	17.16	25.00	4.69
6	35.28	14.33	2.46	16.02	30.00	4.38
7	32.76	13.30	2.46	14.87	35.00	4.06
8	30.24	12.28	2.46	13.73	40.00	3.75
9	27.72	11.26	2.46	12.58	45.00	3.44
10	25.20	10.23	2.46	11.44	50.00	3.13

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