Synergistic Enhancement Effect of Coal Gangue, Fly Ash and Slag in Cement−based Materials
-
摘要:
煤矸石作为煤基固废，其资源化利用受到广泛关注。采用煅烧活化的方式提高了黏土质煤矸石的活性，并将其与粉煤灰、矿渣组合使用，研究了三者在水泥砂浆中的协同增强作用。利用流动性测试和抗压/抗折强度测试，评估了复合水泥砂浆的工作性能和力学性能；利用X射线衍射仪（XRD）、水化热分析了煤矸石的活化机理及复合水泥净浆的水化产物和水化动力学过程。结果表明：随着煅烧温度的升高，煤矸石的活性先增加后降低，最佳煅烧温度在700~800 ℃之间。粉煤灰、矿渣与700 ℃煅烧的煤矸石按照5∶2∶3的质量比组合使用时，水泥砂浆流动度达到237 mm，28 d抗压强度为48.96 MPa，28 d活性指数达到104.77%。其中，粉煤灰的球形颗粒主要起到润滑作用，显著提高了砂浆的流动性；煤矸石提供了大量活性SiO2，促进了水化反应和水化产物的形成；矿渣具有高火山灰活性和细颗粒尺寸，提供了更多成核位置，增强了砂浆的早期强度。三种材料均不同程度地起到了润滑作用和成核作用，实现了流动性协同提升、水化反应协同促进、水化产物优化、活性成分互补等，增强了水泥基材料的性能。本研究为煤矸石在水泥基材料中的应用提供了新的途径和理论依据。
Abstract:Coal gangue, as a coal−based solid waste, has attracted widespread attention for its resource utilization. In this study, the activity of clayey coal gangue was enhanced through calcination activation and combined with fly ash and slag to study the synergistic enhancement effect of the three materials in cement−based materials. The working properties and mechanical properties of the composite cement mortar were evaluated by using the fluidity test and the compressive/flexural strength test. The activation mechanism of coal gangue, the hydration products and hydration kinetics of composite cement slurry were analyzed by X−ray diffraction (XRD) and heat of hydration. The results showed that with increasing calcination temperature, the activity of coal gangue first increased and then decreased, with the optimal calcination temperature between 700–800 ℃. When fly ash, slag, and coal gangue (calcined at 700 ℃) were combined in a ratio of 5∶2∶3, the fluidity of the cement mortar reached 237 mm, the 28 day compressive strength was 48.96 MPa, and the 28−day activity index reached 104.77%. Specifically, the spherical particles of fly ash mainly played a lubricating role, significantly improving the fluidity of the mortar; coal gangue provided a large amount of active SiO2, promoting hydration reactions and the formation of hydration products; slag, with high pozzolanic activity and fine particle size, provided more nucleation sites, enhancing the early strength of the mortar. All three materials all play the role of lubricants and nucleation sites to varying degrees, achieving synergistic improvements in fluidity enhancement, hydration reaction promotion, hydration product optimization, and complementary active components, thereby enhancing the performance of cement−based materials. This study provides a new approach and theoretical basis for the application of coal gangue in cement−based materials.
-
Key words:
- coal gangue /
- calcination activation /
- synergistic effect /
- activity index /
- pozzolanic reaction /
- cement mortar
-
-
表 1 水泥的物理力学性能
Table 1. Basic properties of cement
比表面积
/(m2·kg−1)标准稠度
需水量/%凝结
时间/min抗折
强度/MPa抗压
强度/MPa初凝 终凝 3 d 28 d 3 d 28 d 332 29.6 152 262 6.49 8.81 25.32 46.73 
下载: 导出CSV
表 2 原材料的化学成分
Table 2. Chemical components of raw materials
/% 名称 SiO2 CaO Al2O3 Fe2O3 MgO TiO2 SO3 K2O Na2O 水泥 20.54 64.03 4.51 4.03 1.76 0.42 3.23 1.02 0.31 粉煤灰 51.17 3.65 33.21 6.11 0.71 0.12 1.47 2.27 0.65 煤矸石 62.85 1.05 22.46 4.63 1.16 1.42 0.58 2.93 0.24 矿渣 35.26 36.03 15.26 0.81 9.52 0 1.27 0.43 0.10
下载: 导出CSV
表 3 复合水泥的配合比设计
Table 3. Mix proportion design of composite cement
编号 水泥/% 粉煤灰/% 矿粉/% 煤矸石/% 煅烧温度/℃ 1 70 15 0 15 700 2 70 15 0 15 800 3 70 15 0 15 900 4 70 15 6 9 700 5 70 15 6 9 800 6 70 15 6 9 900
下载: 导出CSV
表 4 复合水泥浆体的水化动力学参数
Table 4. Hydration kinetic parameters of composite cement paste
Sample n K'NG K'I K'D 1 2.2375 0.0521 0.0120 0.0017 2 2.1603 0.0518 0.0124 0.0020 3 2.2448 0.0538 0.0123 0.0015 4 2.1969 0.0512 0.0116 0.0018 5 2.2109 0.0513 0.0117 0.0019 6 2.1462 0.0521 0.0118 0.0018
下载: 导出CSV
-
[1] 晏祥政, 李先海, 王贤晨, 等. 煤矸石粉掺和料对水泥胶砂试块性能影响研究[J]. 非金属矿, 2023, 46(3): 1−5.
YAN X Z, LI X H, WANG X C, et al. Study on the effect of coal gangue powder admixture on the performance of cement mortar test block[J]. Non−metallic Minerals, 2023, 46(3): 1−5.
[2] 王玉涛. 煤矸石固废无害化处置与资源化综合利用现状与展望[J]. 煤田地质与勘探, 2022, 50(10): 54−66.
WANG Y T. Current status and prospect of harmless disposal and comprehensive utilization of coal gangue solid waste[J]. Coal Geology and Exploration, 2022, 50(10): 54−66.
[3] 马骏, 郁钟铭, 舒仕海, 等. 煤矸石对矿区的环境危害及治理措施[J]. 煤炭工程, 2015, 47(10): 70−73.
MA J, YU Z M, SHU S H, et al. Environmental hazards of coal gangue to mining areas and treatment measures[J]. Coal Engineering, 2015, 47(10): 70−73.
[4] LI J, WANG J. Comprehensive utilization and environmental risks of coal gangue: A review[J/OL]. Journal of Cleaner Production, 2019, 239: 117946. https://doi.org/10.1016/j.jclepro.2019.117946.
[5] 熊飞, 王金华. 煤矸石电厂及劣质煤的合理利用[J]. 煤炭科学技术, 2004(8): 4−6.
XIONG F, WANG J H. Rational utilization of coal gangue power plants and low−quality coal[J]. Coal Science and Technology, 2004(8): 4−6.
[6] 常瑞祺, 张建波, 李会泉, 等. 煤基固废制备胶凝材料研究进展及应用[J]. 洁净煤技术, 2024, 30(2): 316−330.
CHANG R Q, ZHANG J B, LI H Q, et al. Research progress and application of cementitious materials prepared from coal−based solid waste[J]. Clean Coal Technology, 2024, 30(2): 316−330.
[7] 李城林, 李晓英, 张超, 等. 基于煅烧煤矸石的复合水泥碳化研究[J]. 武汉理工大学学报, 2023, 45(11): 24−31.
LI C L, LI X Y, ZHANG C, et al. Research on carbonization of composite cement based on calcined coal gangue[J]. Journal of Wuhan University of Technology, 2023, 45(11): 24−31.
[8] 刘泽, 段开瑞, 周梅, 等. 煤矸石在土木工程材料中的应用研究进展[J]. 材料导报, 2024, 38(10): 88−99.
LIU Z, DUAN K R, ZHOU M, et al. Research progress on the application of coal gangue in civil engineering materials[J]. Material Reports, 2024, 38(10): 88−99.
[9] 孔晓俊, 麻杰, 王学明. 煤矸石对土壤微生物活性的影响分析[J]. 山西化工, 2024, 44(5): 20−22.
KONG X J, MA J, WANG X M, et al. Analysis of the effect of coal gangue on soil microbial activity[J]. Shanxi Chemical Industry, 2024, 44(5): 20−22.
[10] 赵莹莹, 高金路, 刘锦英, 等. 煤矸石发电技术浅析[J]. 设备管理与维修, 2017(4): 113−114.
ZHAO Y Y, GAO J L, LIU J Y, et al. Analysis of coal gangue power generation technology[J]. Equipment Management and Maintenance, 2017(4): 113−114.
[11] 顾炳伟, 王培铭. 热激发煤矸石活性影响因素研究[J]. 建筑材料学报, 2009, 12(1): 6−11.
GU B W, WANG P M. Study on the influencing factors of heat−stimulated coal gangue activity[J]. Journal of Building Materials, 2009, 12(1): 6−11.
[12] GUO Z, XU J, XU Z, et al. Performance of cement−based materials containing calcined coal gangue with different calcination regimes[J]. Journal of Building Engineering, 2022, 56: 104821.
GUO Z, XU J, XU Z, et al. Performance of cement−based materials containing calcined coal gangue with different calcination regimes[J]. Journal of Building Engineering, 2022, 56: 104821.
[13] 王朝蓬, 杨洋, 刘宇鹏, 等. 煤矸石制备水泥辅助胶凝材料的应用研究[J]. 水泥工程, 2023(5): 1−4.
WANG C P, YANG Y, LIU Y P, et al. Research on the application of coal gangue to prepare cement auxiliary cementitious materials[J]. Cement Works, 2023(5): 1−4.
[14] CAO Z, CAO Y, DONG H, et al. Effect of calcination condition on the microstructure and pozzolanic activity of calcined coal gangue[J]. International Journal of Mineral Processing, 2016, 146: 23−28.
[15] 丁建彤, 阎培渝, 朱金铨. 含粉煤灰或矿渣与硅灰的不同组合的混凝土(英文)[J]. 山东建材学院学报, 1998(S1): 112−120.
DING J T, YAN P Y, ZHU J Q. Concrete containing fly ash or different combinations of slag and silica fume[J]. Journal of Shandong Institute of Building Materials, 1998(S1): 112−120.
[16] SUN J, ZHANG P. Effects of different composite mineral admixtures on the early hydration and long−term properties of cement−based materials: A comparative study[J]. Construction and Building Materials, 2021, 294: 123547.
[17] HAN X, FENG J, SHAO Y, et al. Influence of a steel slag powder−ground fly ash composite supplementary cementitious material on the chloride and sulphate resistance of mass concrete[J]. Powder Technology, 2020, 370: 176−183.
[18] LIU J, QIU J, WU P, et al. Calcined oil shale residue as a supplementary cementitious material for ordinary Portland cement[J]. Construction and Building Materials, 2021, 306: 124849.
[19] MARSH A, HEATH A, PATUREAU P, et al. Alkali activation behaviour of un−calcined montmorillonite and illite clay minerals[J]. Applied Clay Science, 2018, 166: 250−261.
[20] ALKAÇ D, ATALAY Ü. Kinetics of thermal decomposition of Hekimhan–Deveci siderite ore samples[J]. International Journal of Mineral Processing, 2008, 87(3): 120−128.
[21] ZHAO J, LIU J, WU Y, et al. Application of an industrialized ultrafine composite powder in cement−based materials: Hydration characteristics, microstructure, and corrosion resistance[J]. Construction and Building Materials, 2024, 411: 134629.
[22] SKIBSTED J, SNELLINGS R. Reactivity of supplementary cementitious materials (SCMs) in cement blends[J]. Cement and Concrete Research, 2019, 124: 105799.
[23] 韩方晖, 王栋民, 阎培渝. 含不同掺量矿渣或粉煤灰的复合胶凝材料的水化动力学[J]. 硅酸盐学报, 2014, 42(5): 613−620.
HAN F H, WANG D M, YAN P Y. Hydration kinetics of composite cementitious materials with different amounts of slag or fly ash[J]. Journal of the Chinese Ceramic Society, 2014, 42(5): 613−620.
[24] 孙望超, 颜承越. 粉煤灰形态效应及应用技术[J]. 房材与应用, 1997(2): 35−36.
SUN C W, YAN C Y. Shape effect and application technique of fly ash[J]. Housing Materials & Applications, 1997(2): 35−36.
[25] 宿常智, 黄勇, 杨秋菊, 等. 铁尾矿砂的颗粒级配对干混砂浆性能的影响[J]. 混凝土与水泥制品: 1−4[2024-10-15]. http://kns.cnki.net/kcms/detail/32.1173.TU.20240808.1451.008.html.
SU C Z, HUA Y, YANG Q J, et al. Effects of particle size distribution of iron tailings sand on performance of dry−mixed mortar[J]. China Concrete and Cement Products: 1−4[2024-10-15]. http://kns.cnki.net/kcms/detail/32.1173.TU.20240808.1451.008.html.
[26] WANG S, GU X, LIU J, et al. Modulation of the workability and Ca/Si/Al ratio of cement−metakaolin cementitious material system by using fly ash: Synergistic effect and hydration products[J]. Construction and Building Materials, 2023, 404: 133300.
-
图(7)
表(4)
计量
- 文章访问数: 63
- PDF下载数: 12
- 施引文献: 0