基于晶体生长及形貌的煤灰渣黏温模型

doi:10.11949/0438-1157.20210462

摘要/Abstract

摘要：

采用高温热台显微镜研究了非牛顿煤灰渣结晶过程的晶体生长规律及形貌特征，获得不同化学组成煤渣晶体的种类转变和长宽比变化等参数。基于实验获得的晶体生长规律，耦合晶体形貌、长宽比及熔渣固相随温度的变化关系式，修正悬浮液的黏度模型，建立了适用于非牛顿熔渣的黏温预测模型，并与实测黏温曲线对比和验证。该模型考虑了主要析出以单斜晶系或三斜晶系特征的长石类、黄长石、钙长石和镁硅钙石等单相和多相晶体形貌特征，并结合煤渣固相分数（范围0≤?≤0.8）和长宽比（1.0~16.0）等参数修正。结果发现，模型对于煤渣酸碱比范围为0.5~3.0，煤渣硅铝含量总和35%~70%（质量）范围，CaO含量低于30%（质量）、MgO含量为0~10%（质量）以及Fe₂O₃含量范围低于16%（质量）的煤渣黏度预测适用性较好。

关键词: 气化, 煤灰渣, 结晶, 黏度, 模型

Abstract:

A high-temperature hot-stage microscope was used to study the crystal growth rule and morphological characteristics of the crystallization process of non-Newtonian coal ash slag, and obtain parameters such as the type transformation and the aspect ratio change of the cinder crystals with different chemical compositions. Based on the crystal growth rule from the experiment, the viscosity model of the suspension was modified coupled with the crystal morphology, aspect ratio and the relationship between the slag solid phase and temperature. A viscosity-temperature prediction model suitable for non-Newtonian slag was established in this study, which was compared and verified with the measured viscosity-temperature curve. The model considered the single-phase and multiphase crystal morphology features of feldspar, melilite, anorthite, and merwinite, etc., mainly precipitated as monoclinic or triclinic crystal systems. The model was also modified by combining the parameters of solid fraction of coal slag (range 0≤? ≤0.8) and aspect ratio (1.0—16.0). The results showed that the model was limited as listed conditions, including acidity/basicity ratio of coal slags with ranged of 0.5—3.0, the total content of silicon and aluminum oxides from 35% to 70%(mass), the CaO content lower than 30%(mass), MgO content from 0 to 10%(mass), and the Fe₂O₃ content lower than 16%(mass).

Key words: gasification, coal ash/slag, crystallization, viscosity, model

中图分类号:

TQ 536.4

沈中杰,郭晓镭,梁钦锋,刘海峰. 基于晶体生长及形貌的煤灰渣黏温模型[J]. 化工学报, 2021, 72(10): 5040-5052.

Zhongjie SHEN,Xiaolei GUO,Qinfeng LIANG,Haifeng LIU. Development of coal ash/slag viscosity-temperature model based on crystal growth and morphologies[J]. CIESC Journal, 2021, 72(10): 5040-5052.

图/表 12

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模型	颗粒形貌	体积分数?	特征
Einstein^[26]	球形颗粒	? ≤0.1	适用于低浓度悬浮液
Einstein & Roscoe^[28]	悬浮球体	0≤? ≤0.5	适用于粒径范围宽的悬浮液
Batchelor^[29]	刚性球体	0≤? ≤0.5	适用于低固相浓度悬浮液
Maron & Pierce^[30]	球形颗粒	0≤? ≤0.6	适用于分散相悬浮液
Krieger & Dougherty^[31]	刚性球体	0≤? ≤0.6	考虑聚合作用，单一颗粒
Chong et al.^[32]	球形颗粒	0≤? ≤0.5	具备表征球形颗粒尺寸分布常数
Moitra & Gonnermann^[33]	球形、圆柱形	0≤? ≤0.6	考虑多种形状颗粒和不同颗粒体积比
Zhou et al.^[34]	球形、立方、针状	0≤? ≤0.5	考虑多种形状

模型	颗粒形貌	体积分数?	特征
Einstein^[26]	球形颗粒	? ≤0.1	适用于低浓度悬浮液
Einstein & Roscoe^[28]	悬浮球体	0≤? ≤0.5	适用于粒径范围宽的悬浮液
Batchelor^[29]	刚性球体	0≤? ≤0.5	适用于低固相浓度悬浮液
Maron & Pierce^[30]	球形颗粒	0≤? ≤0.6	适用于分散相悬浮液
Krieger & Dougherty^[31]	刚性球体	0≤? ≤0.6	考虑聚合作用，单一颗粒
Chong et al.^[32]	球形颗粒	0≤? ≤0.5	具备表征球形颗粒尺寸分布常数
Moitra & Gonnermann^[33]	球形、圆柱形	0≤? ≤0.6	考虑多种形状颗粒和不同颗粒体积比
Zhou et al.^[34]	球形、立方、针状	0≤? ≤0.5	考虑多种形状

组成	煤灰/%(质量)
组成	雨田	转龙湾	红沙泉	沙尔湖	神府	神火	将军庙
SiO₂	47.03	40.73	40.07	35.44	39.74	24.25	26.67
Al₂O₃	23.66	19.94	16.86	18.46	12.98	11.01	8.76
CaO	12.22	11.82	8.96	25.43	28.44	27.95	16.04
Fe₂O₃	9.26	8.42	14.03	6.22	13.21	6.07	15.70
MgO	0.74	2.32	5.59	4.87	0.93	9.03	9.60
SO₃	4.24	12.18	7.53	3.08	0.72	17.76	14.51
Na₂O	1.20	3.26	5.40	4.92	2.12	2.53	7.70
K₂O	1.01	0.54	0.62	0.75	1.12	0.77	0.52
TiO₂	0.63	0.79	0.95	0.83	0.74	0.63	0.49
SiO₂+Al₂O₃	70.69	60.66	56.92	53.90	52.72	35.26	35.43
A/B^①	2.92	2.33	1.67	1.30	1.17	0.77	0.72

组成	煤灰/%(质量)
组成	雨田	转龙湾	红沙泉	沙尔湖	神府	神火	将军庙
SiO₂	47.03	40.73	40.07	35.44	39.74	24.25	26.67
Al₂O₃	23.66	19.94	16.86	18.46	12.98	11.01	8.76
CaO	12.22	11.82	8.96	25.43	28.44	27.95	16.04
Fe₂O₃	9.26	8.42	14.03	6.22	13.21	6.07	15.70
MgO	0.74	2.32	5.59	4.87	0.93	9.03	9.60
SO₃	4.24	12.18	7.53	3.08	0.72	17.76	14.51
Na₂O	1.20	3.26	5.40	4.92	2.12	2.53	7.70
K₂O	1.01	0.54	0.62	0.75	1.12	0.77	0.52
TiO₂	0.63	0.79	0.95	0.83	0.74	0.63	0.49
SiO₂+Al₂O₃	70.69	60.66	56.92	53.90	52.72	35.26	35.43
A/B^①	2.92	2.33	1.67	1.30	1.17	0.77	0.72

煤灰	DT/℃	ST/℃	HT/℃	FT/℃
雨田	881	1023	1041	1063
转龙湾	1083	1120	1129	1163
红沙泉	1096	1107	1109	1114
沙尔湖	1193	1242	1247	1255
神府	1168	1173	1176	1184
神火	1204	1229	1231	1236
将军庙	1156	1171	1185	1195