粉煤灰基硅酸镁纳米片的制备及其亚甲基蓝吸附性能

doi:10.16085/j.issn.1000-6613.2024-1684

摘要/Abstract

摘要：

粉煤灰的资源化利用对社会和环境的可持续发展具有重要意义。本文以粉煤灰基硅渣为原料，采用NaOH碱熔法提取SiO₂，在碱熔温度为300℃、碱与灰质量比为2∶1、反应时间为2h的条件下，SiO₂的提取率达到72.26%；进而以提硅得到的Na₂SiO₃溶液和MgO为原料，通过水热反应制备硅酸镁纳米片，考察了Na₂SiO₃溶液浓度、Si与Mg摩尔比、反应温度及反应时间对硅酸镁纳米片的组成、晶相结构和孔道结构的影响规律。结果表明，在Na₂SiO₃浓度为0.50mol/L、Si与Mg摩尔比为1.25∶1、反应温度为220℃和反应时间为10h的条件下制备了结晶度较好、比表面积达240.6m²/g的介孔硅酸镁纳米片；其对亚甲基蓝（MB）具有较快的吸附速率，吸附量达285.0mg/g，对MB的吸附行为符合准二级动力学模型和Langmuir等温吸附模型。

关键词: 吸附剂, 粉煤灰, 二氧化硅, 硅酸镁, 水热合成

Abstract:

The utilization of fly ash is of great significance to the sustainable development of society and environment. NaOH alkali fusion method was adopted to extract SiO₂ from the silicon slag derived from fly ash after extraction of alumina. It was found that the SiO₂ extraction rate reached 72.26% after reaction at 300℃ for 2h with the NaOH and ash mass ratio of 2∶1. Subsequently, MgSiO₃ nanosheets were prepared by hydrothermal reaction using the obtained Na₂SiO₃ solution and MgO as raw materials. The effects of Na₂SiO₃ concentration, Si and Mg molar ratio, reaction temperature and time on the MgSiO₃ product were investigated. XRD, SEM and low temperature N₂ adsorption desorption instrument were used to analyze the composition and structure of the prepared MgSiO₃, and its adsorption performance towards methylene blue (MB) was investigated. MgSiO₃ with high purity, preferable crystallinity and a specific surface area of 240.6m²/g was prepared by reacting at 220℃ for 10h with Na₂SiO₃ concentration of 0.50mol/L and Si and Mg molar ratio of 1.25∶1. The as-prepared MgSiO₃ nanosheets showed fast adsorption rate towards MB with an adsorption capacity of 285.0mg/g. Its adsorption behavior towards MB conformed to the quasi-second-order kinetic model and Langmuir isothermal adsorption model.

Key words: adsorbents, fly ash, silicon dioxide, magnesium silicate, hydrothermal synthesis

中图分类号:

O611.4

刘倩, 李梦茹, 白守礼, 冯拥军, 唐平贵, 李殿卿. 粉煤灰基硅酸镁纳米片的制备及其亚甲基蓝吸附性能[J]. 化工进展, 2025, 44(11): 6716-6729.

LIU Qian, LI Mengru, BAI Shouli, FENG Yongjun, TANG Pinggui, LI Dianqing. Preparation and adsorption performance to methylene blue of fly ash based magnesium silicate nanosheets[J]. Chemical Industry and Engineering Progress, 2025, 44(11): 6716-6729.

图/表 17

图1 MgSiO3制备流程

图2 碱熔温度对提取率的影响及硅渣和提硅渣的XRD图和化学组成

图3 硅渣和提硅渣的SEM图

图4 不同物料浓度合成MgSiO3的XRD谱图和SEM图

图5 不同Na2SiO3浓度合成的MgSiO3的N2吸脱附曲线及孔结构参数

图6 不同硅镁比合成的MgSiO3的XRD谱图和SEM图

图7 不同硅镁比合成的MgSiO3的N2吸脱附曲线及孔结构参数

图8 不同温度合成MgSiO3的XRD谱图和SEM图

图9 不同温度合成MgSiO3的N2吸脱附曲线及孔结构参数

图10 不同反应时间合成MgSiO3的XRD图和SEM图

图11 不同反应时间合成MgSiO3的N2吸脱附曲线及孔结构参数

图12 吸附时间对硅酸镁吸附性能的影响及吸附动力学模型

表1 MgSiO3吸附MB的拟一级动力学和拟二级动力学参数

样品	准一级吸附动力学模型			准二级吸附动力学模型
样品	q₁/mg·g^-1	k₁/min^-1	R²	q₂/mg·g^-1	k₂/ g·mg^-1·min^-1	R²
MgSiO₃（1∶1）	46.64	3.75×10^-2	0.3659	275.5	1.72×10^-3	0.9992
MgSiO₃（1.25∶1）	62.53	4.63×10^-2	0.7430	289.9	1.80×10^-3	0.9998
MgSiO₃（1.5∶1）	44.45	2.75×10^-2	0.6320	255.8	2.03×10^-3	0.9997

图13 25℃下硅酸镁的吸附等温线及吸附热力学拟合

图14 MgSiO3吸附MB前后的FTIR和EDS谱图

图15 MgSiO3吸附MB前后的XPS谱图

表2 不同MgSiO3吸附剂对MB的吸附量对比

吸附剂	比表面积/m²·g^-1	吸附量/mg·g^-1	参考文献
碱活化MgSiO₃	8.6	74.6	[24]
SiO₂@MgSiO₃	588	299	[27]
MgSiO₃	582.3	234.19	[28]
MgSiO₃	521	207	[29]
MgSiO₃纳米管	539.4	175.13	[30]
MgSiO₃纳米管	293	188	[31]
棉/MgSiO₃复合膜	523.1	194.4	[32]
MgSiO₃	240.6	285.0	本文

参考文献 32

[1]	陈岚, 权宇珩, 李志勇, 等. 超声波辅助粉煤灰去除水中亚甲基蓝染料的动力学分析[J]. 化工学报, 2019, 70(7): 2708-2716.
	CHEN Lan, QUAN Yuheng, LI Zhiyong, et al. Kinetic analysis of removal of methylene blue using fly ash assisted by ultrasound from aqueous solution[J]. CIESC Journal, 2019, 70(7): 2708-2716.
[2]	王倩, 李神勇, 康帅, 等. 粉煤灰分质高效利用预处理技术的研究进展[J]. 化工学报, 2023, 74(3): 1010-1032.
	WANG Qian, LI Shenyong, KANG Shuai, et al. Research progress of pretreatment technology for efficient utilization of coal ash[J]. CIESC Journal, 2023, 74(3): 1010-1032.
[3]	张世蕊, 范朕连, 宋慧平, 等. 粉煤灰负载光催化材料的研究进展[J]. 化工进展, 2024, 43(7): 4043-4058.
	ZHANG Shirui, FAN Zhenlian, SONG Huiping, et al. Research progress of fly ash supported photocatalytic materials[J]. Chemical Industry and Engineering Progress, 2024, 43(7): 4043-4058.
[4]	张国卿, 宋舒波, 王兴瑞, 等. 煤固废基分子筛的制备及其应用进展[J]. 化工进展, 2024, 43(5): 2311-2323.
	ZHANG Guoqing, SONG Shubo, WANG Xingrui, et al. Recent advances in the synthesis and application of zeolites from coal-based solid wastes[J]. Chemical Industry and Engineering Progress, 2024, 43(5): 2311-2323.
[5]	马子然, 王宝冬, 路光杰, 等. 粉煤灰基SAPO-34分子筛脱硝催化剂的合成及其脱硝性能[J]. 化工进展, 2020, 39(10): 4051-4060.
	MA Ziran, WANG Baodong, LU Guangjie, et al. Preparation and performance of SAPO-34 based SCR catalyst derived from fly ash[J]. Chemical Industry and Engineering Progress, 2020, 39(10): 4051-4060.
[6]	YADAV Virendra Kumar, FULEKAR Madhusudan Hiraman. Advances in methods for recovery of ferrous, alumina, and silica nanoparticles from fly ash waste[J]. Ceramics, 2020, 3(3): 384-420.
[7]	LIU Huidong. Conversion of harmful fly ash residue to zeolites: Innovative processes focusing on maximum activation, extraction, and utilization of aluminosilicate[J]. ACS Omega, 2022, 7(23): 20347-20356.
[8]	JU Tongyao, JIANG Jianguo, MENG Yuan, et al. An investigation of the effect of ultrasonic waves on the efficiency of silicon extraction from coal fly ash[J]. Ultrasonics Sonochemistry, 2020, 60: 104765.
[9]	TAN Miaomiao, LI Xiangyu, FENG Yu, et al. Fly ash-derived mesoporous silica with large pore volume for augmented CO₂ capture[J]. Fuel, 2023, 351: 128874.
[10]	YAN Kezhou, ZHANG Ting, LIU Dandan, et al. Strengthening desilication of coal fly ash by alkaline leaching with the addition of ethylene diamine tetraacetic acid[J]. Minerals Engineering, 2023, 201: 108219.
[11]	YADAV Virendra Kumar, AMARI Abdelfattah, WANALE Shivraj Gangadhar, et al. Synthesis of floral-shaped nanosilica from coal fly ash and its application for the remediation of heavy metals from fly ash aqueous solutions[J]. Sustainability, 2023, 15(3): 2612.
[12]	JU Tongyao, MENG Yuan, HAN Siyu, et al. A green and multi-win strategy for coal fly ash disposal by CO₂ fixation and mesoporous silica synthesis[J]. Science of the Total Environment, 2023, 883: 163822.
[13]	BAO Jing, FENG Yongjun, PAN Yong, et al. Modified approaches to prepare nano-magnesium silicates with hierarchical pore structure and their performance towards adsorption of Cd²⁺ [J]. Environmental Science and Pollution Research International, 2023, 30(38): 89784-89793.
[14]	GHODS Bahare, REZAEI Mehran, MESHKANI Fereshteh. Synthesis of nanostructured magnesium silicate with high surface area and mesoporous structure[J]. Ceramics International, 2016, 42(6): 6883-6890.
[15]	ZHAO Rui, LI Yanzi, SUN Bolun, et al. Highly flexible magnesium silicate nanofibrous membranes for effective removal of methylene blue from aqueous solution[J]. Chemical Engineering Journal, 2019, 359: 1603-1616.
[16]	WANG Bin, GAO Kai, WANG Yujie, et al. Synergistic dispersion, adsorption, and anti-wear effects of magnesium silicate hydroxide nanomaterials and carboxylic acid[J]. Applied Surface Science, 2024, 665: 160373.
[17]	XING Lang, LI Xinran, CAO Pengxu, et al. Stepwise extraction and utilization of silica and alumina from coal fly ash by mild hydrothermal process[J]. Process Safety and Environmental Protection, 2024, 182: 918-929.
[18]	WANG Xuekai, WANG Jinshu, TENG Weili, et al. Fabrication of highly efficient magnesium silicate and its adsorption behavior towards Cr(Ⅵ)[J]. Microporous and Mesoporous Materials, 2021, 323: 111196.
[19]	HE Zhendong, REN Bozhi, HURSTHOUSE Andrew, et al. Efficient removal of Cd(Ⅱ) using SiO₂-Mg(OH)₂ nanocomposites derived from sepiolite[J]. International Journal of Environmental Research and Public Health, 2020, 17(7): 2223.
[20]	SUN Zhiwei, LIU Yanhua, SRINIVASAKANNAN Chandrasekar. One-pot fabrication of rod-like magnesium silicate and its adsorption for Cd²⁺ [J]. Journal of Environmental Chemical Engineering, 2020, 8(5): 104380.
[21]	PAYAN François, ISSA Albert, KRAFFT Jean-Marc, et al. Controlling magnesium silicates coprecipitation conditions: A tool to tune their surface acid-base reactivity[J]. Catalysts, 2023, 13(11): 1393.
[22]	SUN Zhiwei, LIU Yanhua, HONG Wei. Facile synthesis of porous hydrated magnesium silicate adsorbent from ordinary silica gel[J]. Materials Letters, 2020, 272: 127886.
[23]	WANG Weixue, CHEN Zhe, ZHOU Haijiang, et al. Two-dimensional lamellar magnesium silicate with large spacing as an excellent adsorbent for uranium immobilization[J]. Environmental Science: Nano, 2018, 5(10): 2406-2414.
[24]	Kardelen KAYA-ÖZKIPER, UZUN Alper, Sezen SOYER-UZUN. A novel alkali activated magnesium silicate as an effective and mechanically strong adsorbent for methylene blue removal[J]. Journal of Hazardous Materials, 2022, 424: 127256.
[25]	SUN Zhiwei, HUANG Di, DUAN Xinhui, et al. Functionalized nanoflower-like hydroxyl magnesium silicate for effective adsorption of aflatoxin B1[J]. Journal of Hazardous Materials, 2020, 387: 121792.
[26]	LI Qiang, ZHANG Jingjing, LU Qingshan, et al. Hydrothermal synthesis and characterization of ordered mesoporous magnesium silicate-silica for dyes adsorption[J]. Materials Letters, 2016, 170: 167-170.
[27]	TIAN Yaxi, CUI Guijia, LIU Yan, et al. Self-assembly synthesis of hollow double silica@mesoporous magnesium silicate magnetic hierarchical nanotubes with excellent performance for fast removal of cationic dyes[J]. Applied Surface Science, 2016, 387: 631-641.
[28]	ZHAO Wenting, FENG Ke, ZHANG Huan, et al. Sustainable green conversion of coal gangue waste into cost-effective porous multimetallic silicate adsorbent enables superefficient removal of Cd(Ⅱ) and dye[J]. Chemosphere, 2023, 324: 138287.
[29]	WANG Yongqiang, WANG Guozhong, WANG Hongqiang, et al. Chemical-template synthesis of micro/nanoscale magnesium silicate hollow spheres for waste-water treatment[J]. Chemistry—A European Journal, 2010, 16(11): 3497-3503.
[30]	YANG Jinbo, ZHANG Min, ZHANG Yanwei, et al. Facile synthesis of magnetic magnesium silicate hollow nanotubes with high capacity for removal of methylene blue[J]. Journal of Alloys and Compounds, 2017, 721: 772-778.
[31]	ZHENG Jun, CHENG Chao, YAN Ruiwen, et al. Synthesis of yolk-shell magnetic magnesium silicate with tunable yolk morphology for removal of methylene blue in water[J]. Journal of Alloys and Compounds, 2014, 596: 5-9.
[32]	BIAN Shaowei, HUANG Yali, YUE Yuan, et al. Porous cotton/magnesium silicate composite films as high-performance adsorbents for organic dye removal[J]. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2021, 625: 126751.