热活化煤矸石及其在磷石膏矿渣水泥中的应用研究

doi:10.16552/j.cnki.issn1001-1625.2026.0086

摘要/Abstract

摘要：

针对磷石膏大规模消纳与磷石膏矿渣水泥中矿粉供应短缺的双重难题，本文系统研究了热活化煤矸石作为矿粉替代材料的可行性及其对水泥性能的影响机制，以推动工业固废资源化利用。将煤矸石在600~800 ℃下煅烧活化，并以不同质量分数（10%~100%）替代矿粉，系统评价了材料的力学性能、水化进程与微观结构演变规律。结果表明：在早期龄期（7 d），700 ℃活化煤矸石在20%替代率下表现出最佳增强效果，抗压强度较对照组提升12.38%；在后期龄期（28 d），600 ℃活化煤矸石在20%替代率下力学性能最优，抗压强度提升达53.62%。物相分析表明，热活化促使煤矸石中高岭土相转变为偏高岭土，显著提高了活性硅铝的溶出率与火山灰反应活性，进而促进了更多钙矾石（AFt）和C-（A）-S-H凝胶的生成。水化热分析证实，热活化材料能够加速早期水化进程，缩短诱导期。本研究证实热活化煤矸石是磷石膏矿渣水泥体系中矿粉的有效替代材料，为大宗固废高值化利用和低碳胶凝材料开发提供了重要的技术支撑。

关键词: 磷石膏矿渣水泥, 煤矸石, 热活化, 力学性能, 物相分析, 水化机理

Abstract:

To address the dual challenges of large-scale phosphogypsum disposal and mineral powder shortage in phosphogypsum slag cement， this study systematically investigated the feasibility of thermally activated coal gangue as a substitute for mineral powder and its influence mechanism on cement performance， while promoting the resource utilization of industrial solid waste. Coal gangue was calcined at 600 ℃ to 800 ℃ for activation and was used to replace mineral powder at various mass fractions （10% to 100%）. The mechanical properties， hydration process， and microstructural evolution of the materials were comprehensively evaluated. The results demonstrate that at early age （7 d）， coal gangue activated at 700 ℃ exhibits optimal enhancement at a 20% replacement rate， with compressive strength increasing by 12.38% compared to the control group. At later age （28 d）， coal gangue activated at 600 ℃ demonstrates superior mechanical performance at a 20% replacement rate， achieving a compressive strength increase of 53.62%. Phase analysis reveals that thermal activation transforms kaolinite in coal gangue into metakaolinite， significantly enhancing the leaching rate of reactive silica and alumina and thereby promoting pozzolanic reactivity， which facilitates increased formation of ettringite （AFt） and C-（A）-S-H gel. Hydration heat analysis confirms that thermally activated materials accelerate the early-stage hydration process and shorten the induction period. This study demonstrates that thermally activated coal gangue can serve as an effective substitute for mineral powder in phosphogypsum slag cement systems， providing crucial technical support for the high-value utilization of bulk solid waste and the development of low-carbon cementitious materials.

Key words: phosphogypsum slag cement, coal gangue, thermal activation, mechanical property, phase analysis, hydration mechanism

中图分类号:

TQ172.1

唐佩, 刘佳心, 曲波, 肜鹏杰, 陈伟. 热活化煤矸石及其在磷石膏矿渣水泥中的应用研究[J]. 硅酸盐通报, 2026, 45(8): 2829-2838.

TANG Pei, LIU Jiaxin, QU Bo, RONG Pengjie, CHEN Wei. Thermally Activated Coal Gangue and Its Application in Phosphogypsum Slag Cement[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2026, 45(8): 2829-2838.

图/表 12

表1 原材料的主要化学组成

Table 1 Main chemical composition of raw materials

Material	Mass fraction/%
Material	Al₂O₃	SiO₂	Na₂O	MgO	CaO	SO₃	K₂O	P₂O₅	Fe₂O₃	MnO	F	LOI
PG	0.73	7.49	0.11	0.24	33.38	44.87	0.39	0.68	0.50	—	1.15	10.10
GGBS	14.36	29.93	0.35	7.80	43.19	2.51	0.39	0.02	0.28	0.22	—	—
OPC	4.81	19.18	0.21	1.26	63.29	3.84	0.93	0.17	3.24	0.28	—	2.08
CG	21.45	22.30	0.04	0.10	0.80	4.70	0.16	0.03	1.96	—	—	47.44

图1 原材料的物相组成和粒径分布

Fig.1 Phase composition and particle size distribution of raw material

图2 不同温度下热活化煤矸石的XRD谱

Fig.2 XRD patterns of thermally activated coal gangue at different temperatures

图3 热活化煤矸石的Si4+和Al3+溶出率及活性指数

Fig.3 Leaching rate of Si4+ and Al3+ from thermally activated coal gangue and their reactivity index

图4 试样的抗压强度

Fig.4 Compressive strength of samples

图5 试样水化放热量及累积放热量

Fig.5 Heat flow and cumulative heat release of samples

表2 水化热曲线相关参数

Table 2 Relative parameters of hydration heat curves

Sample	Duration of individual stage/h			Heat release of individual stage/（J·g^-1）
Sample	Stage Ⅰ	Stage Ⅱ	Stage Ⅲ	Stage Ⅰ	Stage Ⅱ	Stage Ⅲ
Ref	2.81	66.78	90.41	9.33	8.53	91.50
CG-600-30%	4.58	66.60	88.82	9.03	9.75	90.73
CG-700-30%	4.35	63.97	96.03	7.64	10.03	93.67
CG-800-30%	3.66	59.62	94.71	7.69	10.55	85.66

图6 试样水化7和28 d后的XRD谱

Fig.6 XRD patterns of samples after 7 and 28 d hydration

图7 试样水化7和28 d后的FTIR谱

Fig.7 FTIR spectra of samples after 7 and 28 d hydration

图8 试样水化7和28 d后的TG-DTG曲线

Fig.8 TG-DTG curves of samples after 7 and 28 d hydration

表3 试样在不同温度区间的质量损失

Table 3 Mass loss of samples at different temperature ranges

Sample	7 d				28 d
	Peak 1		Peak 2		Peak 1		Peak 2
	Temperature/℃	Mass loss/%	Temperature/℃	Mass loss/%	Temperature/℃	Mass loss/%	Temperature/℃	Mass loss/%
Ref	97.74	4.70	138.33	9.52	98.82	5.12	138.44	9.35
CG-600-30%	101.16	6.68	139.38	10.41	106.15	8.59	140.34	10.21
CG-700-30%	95.48	6.62	134.24	8.93	109.59	8.66	141.96	10.41
CG-800-30%	102.39	6.82	140.38	10.53	106.73	7.66	142.38	10.32

图9 试样水化28 d后的SEM照片

Fig.9 SEM images of samples after 28 d hydration

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