Preparation and application of high accumulation solidified foam for preventing coal spontaneous combustion
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摘要:
漏风是引发矿井煤自燃的重要原因，而煤自燃火灾影响了矿井的正常生产。为解决传统无机固化泡沫(TISF)在充填堵漏过程中存在胶凝时间长、堆积能力弱的问题，提出经液态硅酸钠(LSS)改性制备的速凝无机固化泡沫(RISF)。研究了不同掺量的LSS对泡沫浆液胶凝时间、堆积能力等性能的影响规律，采用抗压强度、稳定性测试等表征手段，确定了LSS的最优添加量为5%(质量分数)，RISF的28 d抗压强度达2.49 MPa，是TISF的1.7倍，最大密度比R为1.11，稳定性提升20%左右；胶凝时间和堆积能力的测试结果表明，与TISF相比，RISF的凝结时间大幅缩短(从683 s缩短到52 s)，堆积能力提升(最大堆积高度提高1.9倍)。基于此，结合扫描电子显微镜(SEM)和X射线衍射(XRD)对RISF的速凝固化机理进行了探究。试验结果表明，RISF具有更多的水化产物且不同的水化产物紧密交织，颗粒水化过程中，LSS水解生成原硅酸根与溶液中的钙离子结合，加快水化反应，缩短了泡沫浆液的胶凝时间。但也发现，当LSS添加量超过5%时，RISF的抗压强度降低，稳定性下降，这主要是因为过量的LSS使溶液中的钙硅比例低于1.0，导致生成了低强度的水化产物。堵漏风试验和灭火试验结果表明，与TISF相比，RISF具有较高的堵漏效率和优良的防灭火性能，堵漏效率最高提升26.3%，并且在扑灭煤火时未出现复燃。RISF在利民煤矿矸石山的现场应用表明，其具有良好的降温灭火效果，有效解决了矸石山的高温难题，确保了矿井的正常生产。
Abstract:Air leakage is an important cause of coal spontaneous combustion in mines, which affect the normal production of the mine. In order to solve the problems of long gelling time and weak stacking ability of traditional inorganic solidified foam (TISF) in the process of filling and plugging, a rapid setting inorganic solidified foam (RISF) modified by liquid sodium silicate (LSS) was proposed. The influence of different dosages of LSS on the gelling time, stacking capacity and other properties of foam slurry was studied. By means of compressive strength, stability test and other characterization methods, the optimal addition amount of LSS was determined to be 5% (mass fraction). The 28 d compressive strength of RISF reached 2.49 MPa, 1.7 times that of TISF. The maximum density ratio R was 1.11, and the stability increased by about 20%; The test results of gelation time and stacking ability showed that compared with TISF, the setting time of RISF was significantly shortened (from 683 s to 52 s), and the stacking ability was improved (the maximum stacking height is increased by 1.9 times). Based on this, the rapid curing mechanism of RISF was explored by combining scanning electron microscope (SEM) and X-ray diffraction (XRD). The test results showed that RISF had more hydration products and different hydration products were closely intertwined. During the particle hydration process, LSS hydrolyzed to generate the orthosilicate and combined with calcium ions in the solution, which accelerated the hydration reaction and shortened the gelling time of foam slurry. However, it was also found that when the amount of LSS added exceeded 5%, the compressive strength and stability of RISF decreased. This is mainly because excessive LSS caused the calcium silicon ratio in the solution to be lower than 1.0, resulting in the formation of low strength hydration products. The results of air blockage and fire extinguishing tests showed that compared with TISF, RISF had higher air blockage efficiency and excellent fire prevention and extinguishing performance, with a maximum increase of 26.3% in blockage efficiency, and no reignition occurred when extinguishing coal fires. The on-site application of RISF in the gangue hill of Limin Coal Mine has shown that it has good cooling and fire extinguishing effects, effectively solving the high temperature problem of the gangue hill, and ensuring the normal production of the mine.
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图 8 LSS掺量对泡沫浆液流动与堆积性的影响
Figure 8. Effect of LSS dosage on flow and accumulation of foam slurry
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图 9 不同浓度LSS掺量泡沫浆液的堆积扩散示意
Figure 9. Schematic of accumulation and diffusion of foam grout with different concentrations of LSS
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图 10 不同固化泡沫14 d的SEM–EDS图像
Figure 10. SEM–EDS images of different solidified foam for 14 days
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图 11 不同固化泡沫14 d的X射线衍射图像
Figure 11. X-ray diffraction images of 14 days different solidified foam
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图 13 不同固化泡沫7 d的堵漏风效率
Figure 13. Air plugging efficiency of different curing foam 7 days
表 1 不同粉体材料的化学成分和物理性能
Table 1 Chemical composition and physical properties of different powder materials
材料 水泥 粉煤灰 CaO质量分数/% 53.08 1.75 MgO质量分数/% 12.55 0.641 Al2O3质量分数/% 6.00 32.59 Fe2O3质量分数/% 3.67 2.36 SO3质量分数/% 3.60 0.318 Na2O质量分数/% 0.33 0.431 SiO2质量分数/% 19.12 58.93 TiO2质量分数/% 0.38 1.06 体积密度/(kg·m−3) 875 715 比表面积/(m2·kg−1) 341 4569 中值粒径d50/nm 2901 1540 
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表 2 固化泡沫的混合设计
Table 2 Mixed design of cured foam
编号 水泥质量/g 粉煤灰质量/g 水灰质量比 水质量/g 泡沫添加量 质量分数/% SDS PVA–NS LSS GX MgO PCE TISF 67.33 32.67 0.5 50 2.2V — — — — — R1 67.33 32.67 0.5 50 — 2.2V 1 0.5 2 0.45 R3 67.33 32.67 0.5 50 — 2.2V 3 0.5 2 0.45 R5 67.33 32.67 0.5 50 — 2.2V 5 0.5 2 0.45 R7 67.33 32.67 0.5 50 — 2.2V 7 0.5 2 0.45 注：V为水泥基浆液的体积。
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表 3 固化泡沫的干、湿密度及抗压强度
Table 3 Dry and wet density and compressive strength of cured foam
编号 湿密度/（kg·m−3） 干密度/（kg·m−3） 抗压强度/MPa 7 d 14 d 28 d TISF 782 704 0.714 39 1.065 06 1.444 45 R1 803 735 1.215 38 1.596 65 1.795 12 R3 812 744 1.402 29 1.777 75 2.055 54 R5 825 745 1.598 22 2.010 20 2.497 55 R7 808 736 1.489 31 1.853 94 2.230 26
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表 4 不同固化泡沫的堵漏风效率
Table 4 Air plugging efficiency of different solidified foam
编号 预设气体流速/(L·min−1) 平均堵漏风效率/% 气体压力0.06 MPa 气体压力0.12 MPa 气体压力0.18 MPa 气体压力0.24 MPa TISF 2.00 87.17 84.90 74.77 60.37 4.00 85.37 81.67 71.63 54.83 6.00 80.80 78.33 67.10 48.43 8.00 76.73 73.03 62.03 44.20 R1 2.00 94.67 90.73 86.03 78.60 4.00 90.53 85.47 80.77 66.80 6.00 86.03 80.00 76.20 59.67 8.00 81.97 75.23 69.23 54.90 R3 2.00 100.00 98.53 92.23 83.97 4.00 98.70 95.60 87.10 75.97 6.00 95.77 93.47 80.20 69.30 8.00 92.97 89.87 75.17 61.73 R5 2.00 100.00 100.00 96.20 87.93 4.00 100.00 99.60 92.63 80.10 6.00 100.00 99.33 86.07 74.97 8.00 99.70 98.43 80.67 69.80 R7 2.00 100.00 98.27 92.70 85.23 4.00 100.00 96.10 88.67 78.60 6.00 97.30 93.23 83.20 71.87 8.00 94.50 89.43 77.50 65.97
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[1] 林 刚,付晶莹,江 东,等. 中国煤炭去产能的水资源协同效益分析[J]. 煤炭科学技术,2023,51(7):187−196. LIN Gang,FU Jingying,JIANG Dong,et al. Analysis of water synergy benefits of coal de-capacity in China[J]. Coal Science and Technology,2023,51(7):187−196.
[2] 刘 峰,曹文君,张建明,等. 我国煤炭工业科技创新进展及“十四五”发展方向[J]. 煤炭学报,2021,46(1):1−15. LIU Feng,CAO Wenjun,ZHANG Jianming,et al. Current technological innovation and development direction of the 14th Five-Year Plan period in China coal industry[J]. Journal of China Coal Society,2021,46(1):1−15.
[3] XI Xian,SHI QuanLin. Study of the preparation and extinguishment characteristic of the novel high−water−retaining foam for controlling spontaneous combustion of coal[J]. Fuel,2021,288:119354. doi: 10.1016/j.fuel.2020.119354
[4] 胡相明. 矿用充填堵漏风新型复合泡沫的研制[D]. 徐州:中国矿业大学,2013:1–4. HU Xiangming. Study on a new composite foam for air-leakage blocking in mine[D]. Xuzhou:China University of Mining and Technology,2013:1–4.
[5] SHE Wei,ZHENG Zhihao,ZHANG Qunchao,et al. Predesigning matrix−directed super−hydrophobization and hierarchical strengthening of cement foam[J]. Cement and Concrete Research,2020,131:106029. doi: 10.1016/j.cemconres.2020.106029
[6] XUE Di,HU Xiangming,CHENG Weimin,et al. Development of a novel composite inhibitor modified with proanthocyanidins and mixed with ammonium polyphosphate[J]. Energy,2020,213:118901. doi: 10.1016/j.energy.2020.118901
[7] 王毅泽,董凯丽,张玉龙,等. CMC/ZrCit/GDL防灭火凝胶泡沫的制备及特性研究[J]. 煤炭科学技术,2023,51(6):122−129. WANG Yize,DONG Kaili,ZHANG Yulong,et al. Study on preparation and characteristics of CMC/ZrCit/GDL fire-fighting gel foam[J]. Coal Science and Technology,2023,51(6):122−129.
[8] 金永飞,李传省,程 明. 发泡水泥固化充填材料的研究及应用[J]. 煤矿安全,2020,51(6):37−42. JIN Yongfei,LI Chuansheng,CHENG Ming. Study and application of foamed cement solidified filling materials[J]. Safety in Coal Mines,2020,51(6):37−42.
[9] 鲁 义. 防治煤炭自燃的无机固化泡沫及特性研究[D]. 徐州:中国矿业大学,2015:43–47. LU Yi. Study on the inorganic solidified foam and its characteristics for preventing and controlling spontaneous combustion of coal[D]. Xuzhou:China University of Mining and Technology,2015:43–47.
[10] 马 砺,杜 素,张照允,等. 采空区大掺量粉煤灰无机固化泡沫制备及特性研究[J]. 煤田地质与勘探,2023,51(2):243−251. MA Li,DU Su,ZHANG Zhaoyun,et al. Preparation and characteristics of inorganic curing foam with large-volume fly ash ingoaf[J]. Coal Geology & Exploration,2023,51(2):243−251.
[11] 房秀政,鲁 义,王 刚,等. 矿井火灾防治材料研究现状及展望[J]. 能源与环保,2020,42(8):164−167. FANG Xiuzheng,LU Yi,WANG Gang,et al. Research status and prospect of mine fire prevention materials[J]. China Energy and Environmental Protection,2020,42(8):164−167.
[12] HEIKAL M. Effect of calcium formate as an accelerator on the physicochemical and mechanical properties of pozzolanic cement pastes[J]. Cement and Concrete Research,2004,34:1051−1056. doi: 10.1016/j.cemconres.2003.11.015
[13] 张 慢. 化学外加剂对水泥水化历程的调控及作用机理研究[D]. 武汉:武汉理工大学,2010. ZHANG Man. Regulation and mechanism of chemical admixtures on cement hydration process[D]. Wuhan:Wuhan University of Technology,2010.
[14] QI Yanhan,LI Shucai,LI Zhaofeng,et al. Hydration effect of sodium silicate on cement slurry doped with xanthan[J]. Construction and Building Materials,2019,233:967−85.
[15] 孙星亮,张岳峰. 富水隧洞注浆用水泥–水玻璃浆液室内配比试验研究[J]. 铁道建筑,2019,59(4):83−86. SUN Xingliang,ZHANG Yuefeng. Experimental Study on Cement-water Glass Composite Slurry Indoor Proportioning for Water-rich Tunnel Grouting[J]. Railway Engineering,2019,59(4):83−86.
[16] HUANG G,PUDASAINEE D,GUPTA R,et al,Utilization and performance evaluation of molasses as a retarder and plasticizer for calcium sulfoaluminate cement-based mortar[J]. Construction and Building Materials,2020,243:118201.
[17] SHE Wei,DU Yi,MIAO Changwen,et al. Application of organic- and nanoparticle-modified foams in foamed concrete:reinforcement and stabilization mechanisms[J]. Cement and Concrete Research,2018,106:12−22. doi: 10.1016/j.cemconres.2018.01.020
[18] XIONG Yuanliang,LI Baoliang,CHEN Chun,et al. Properties of foamed concrete with Ca(OH)2 as foam stabilizer[J]. Cement and Concrete Composites,2021,118:103985. doi: 10.1016/j.cemconcomp.2021.103985
[19] XUE Di,HU Xiangming,DONG Hao,et al. Examination of characteristics of anti-oxidation compound inhibitor for preventing the spontaneous combustion of coal[J]. Fuel,2022,310:122160. doi: 10.1016/j.fuel.2021.122160
[20] YANG Renhe,HE Tingshu,GUAN Mengqin,et al. Preparation and accelerating mechanism of aluminum sulfate-based alkali-free accelerating additive for sprayed concrete[J]. Construction and Building Materials,2020,234:117334. doi: 10.1016/j.conbuildmat.2019.117334
[21] TOBIAS Dorn,OLIVER Blask,DIETMAR Stephan. Acceleration of cement hydration – a review of the working mechanisms,effects on setting time,and compressive strength development of accelerating admixtures[J]. Construction and Building Materials,2022,323:126554. doi: 10.1016/j.conbuildmat.2022.126554
[22] BARBARA Lothenbach,ANDRE Nonat. Calcium silicate hydrates:solid and liquidphase composition[J]. Cement and Concrete Research,2015,78:57−70. doi: 10.1016/j.cemconres.2015.03.019
[23] ZHANG Shaofeng,NIU Ditao. Hydration and mechanical properties of cement-steel slag system incorporating different activators[J]. Construction and Building Materials,2023,363:129981. doi: 10.1016/j.conbuildmat.2022.129981
[24] 奚 弦. 工业固废基复合浆泡材料的研制及堵漏防灭火特性研究 [D]. 徐州:中国矿业大学,2022. XI Xian. Study on the preparation and fire prevention characteristics of industrial solid waste based composite slurry foam materials[D]. Xuzhou:China University of Mining and Technology,2022.
[25] HUANG Guodong,JI Yongsheng,LI Jun,et al. Improving strength of calcinated coal gangue geopolymer mortars via increasing calcium content[J]. Construction and Building Materials,2018,166:760−768. doi: 10.1016/j.conbuildmat.2018.02.005
[26] HAMED Maraghechi,FARSHAD Rajabipour,CARLO G. Pantano,et al. Effect of calcium dissolution and precipitation reactions of amorphous silica athigh alkalinity[J]. Cement and Concrete Research,2016,87:1−13. doi: 10.1016/j.cemconres.2016.05.004
[27] HUANG Guodong,JI Yongsheng,LI Jun,et al. Effect of activated silica on polymerization mechanism and strengthdevelopment of MSWI bottom ash alkali-activated mortars[J]. Construction and Building Materials,2019,201:90−99. doi: 10.1016/j.conbuildmat.2018.12.125
[28] KAPELUSZNA E.,KOTWICA Ł.,RÓ_ZYCKA A.,et al. Incorporation of Al in C–A-S–H gels with various Ca/Si and Al/Si ratio:microstructural and structural characteristics with DTA/TG,XRD,FTIR and TEM analysis[J]. Construction and Building Materials,2017,155:643–653.
[29] 王 海,许刚刚,王晓东,等. 低温环境下添速凝剂的水泥浆凝结特性试验研究[J]. 煤炭科学技术,2019,47(8):78−83. WANG Hai,XU Ganggang,WANG Xiaodong,et al. Experimental study on coagulation characteristics of cement slurrywith quick-setting agent at low temperature[J]. Coal Science and Technology,2019,47(8):78−83.
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