Sustainable synthesis of ZSM-5 zeolite from iron ore tailings
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摘要: 针对河北承德某地区铁尾矿硅铝含量高的特点，以该尾矿为原料制备ZSM-5分子筛。目前，以固体废弃物为原料合成分子筛通常采用水热法，合成工艺复杂、单釜利用率低且产生废水，严重限制了以固体废弃物为原料合成分子筛的大规模应用。该研究提出以无溶剂法合成ZSM-5分子筛，在分子筛合成过程中无液体溶剂参与，因此更加绿色环保。研究表明，ZSM-5分子筛最佳合成参数为：HDA/SiO2=0.1、Na2CO3·10H2O/SiO2=0.4，150 °C晶化6 d，此时得到的ZSM-5分子筛同时具有介、微复合孔结构，其中微孔表面积为213.2 m2/g，外表面积为95.53 m2/g。此外，无溶剂法合成分子筛的元素利用率高于传统水热法，无溶剂法Si和Al的元素利用率分别为94.83%、95.89%，而水热法仅为80%左右。Abstract: In view of the high silicon and aluminum content of iron ore tailings (IOT) in Chengde, Hebei province, ZSM-5 zeolite was prepared with IOT as the raw materials. At present, the synthesis of zeolite from solid waste usually uses hydrothermal method, which is a complex synthesis process with low utilization rate of single reactor and produces wastewater. Our approach focused on reutilization of IOT by converting it to ZSM-5 via solvent-free method. It shows that the optimal synthesis parameters of ZSM-5 zeolite are HDA/SiO2=0.1, Na2CO3·10H2O/SiO2=0.4, and crystallization at 150 ℃ for 6 days. The obtained ZSM-5 zeolite has bimodal meso- and micro-porous structure, with a surface area of micropores of 213.25 m2∙g−1 and an external surface area of 95.53 m2∙g−1. In addition, the elemental utilization rate of the solvent-free method is higher than that of the conventional hydrothermal method, and the elemental utilization rates of Si and Al for the solvent-free method are 94.83% and 95.89%, respectively, while those for the hydrothermal method were only 80%.
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Key words:
- iron ore tailings /
- ZSM-5 zeolite /
- solvent-free method /
- crystallization time /
- surface area
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图 1 铁尾矿无溶剂制备ZSM-5分子筛示意
Figure 1. Schematic diagram of solvent-free preparation of ZSM-5 molecular sieve from IOT
图 2 不同晶化时间产物的XRD谱
Figure 2. XRD patterns of products with different crystallization time
图 3 不同晶化时间样品的SEM-EDS图像
Figure 3. SEM-EDS images of samples at different crystallization time
图 4 不同Na2CO3·10H2O/SiO2摩尔比样品XRD谱
Figure 4. XRD patterns of samples with different Na2CO3·10H2O/SiO2 molar ratios
图 5 不同HDA/SiO2摩尔比产物的XRD谱
Figure 5. XRD patterns of products with different HDA/SiO2 molar ratios
图 6 铁尾矿、ZSM-5分子筛的氮气吸附脱附曲线（a）和BJH吸附孔径分布（b）
Figure 6. N2 adsorption–desorption isotherms (a) and BJH adsorption pore distributions (b) of IOT and ZSM-5 zeolite
表 1 预处理前后铁尾矿成分
Table 1. The compositions of IOT before and after treatment
% SiO2 Al2O3 杂质 Fe2O3 CaO K2O MgO Na2O 预处理前 68.64 13.14 9.47 3.41 2.24 2.26 0.74 预处理后 91.91 1.51 2.49 1.10 0.49 0.60 1.79 
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表 2 铁尾矿和ZSM-5分子筛的吸脱附数据
Table 2. Physicochemical properties of IOT and ZSM-5 zeolite
比表面积/
( m2∙g−1)微孔表面积/
( m2∙g−1)外表面积/
( m2∙g−1)孔体积/
(cm3∙g−1)微孔体积/
( cm3∙g−1)介孔体积/
(cm3∙g−1)BJH吸附平均
直径/nm铁尾矿 26.51 1.08 25.43 0.042 0.042 2.142 ZSM-5 分子筛 308.78 213.25 95.53 0.196 0.1104 0.092 4.587
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[1] Yan Qinping. Study on the development and utilization of iron ore tailings in China[J]. Scrap Iron and Steel in China, 2014,(3):33−38. (闫启平. 我国铁矿尾矿渣粉开发利用之研究[J]. 中国废钢铁, 2014,(3):33−38. [2] Zhang Peng, Chen Xingyue, Ren Zhifeng, et al. Investigating kinetics in preparation of precipitated silica from iron ore tailings[J]. Iron Steel Vanadium Titanium, 2014,43(3):33−38. (张鹏, 陈星月, 任志峰, 等. 铁尾矿煅烧酸浸法制备白炭黑及动力学研究[J]. 钢铁钒钛, 2014,43(3):33−38. [3] Deng Wen, Jiang Dengbang, Yang Bo, et al. Comprehensive utilization status and existing problems of iron tailings in China[J]. Modern Mining, 2012,(9):1−3. (邓文, 江登榜, 杨波, 等. 我国铁尾矿综合利用现状和存在的问题[J]. 现代矿业, 2012,(9):1−3. doi: 10.3969/j.issn.1674-6082.2012.09.001 [4] Mc Donald J E D, Roache S S C, Kawatra K. Repurposing mine tailings: Cold bonding of siliceous iron ore tailings[J]. Minerals & Metallurgical Processing, 2016,31(1):47−52. [5] Osinubi K J, Yohanna P, Eberemu A O. Cement modification of tropical black clay using iron ore tailings as admixture[J]. Transportation Geotechnics, 2015,10(5):35−49. [6] Sirkeei A A, Gul A, Bulut G. Recovery of Co, Ni, and Cu from the tailings of divrigi iron ore concentrator[J]. Mineral Processing and Extractive Metallurgy Review, 2006,27(2):131−141. doi: 10.1080/08827500600563343 [7] Wang C L, Ni W, Zhang S Q, et al. Preparation and properties of autoclaved aerated concrete using coal gangue and iron ore tailings[J]. Construction and Building Materials, 2016,104(1):109−115. [8] Liu X F, Zhang S J, Wang R W, et al. Sustainable synthesis of hierarchically porous silicalite-1 zeolite by steam-assisted crystallization of solid raw materials without secondary templates[J]. Chemical Research in Chinese Universities, 2018,34(3):350−357. doi: 10.1007/s40242-018-7400-2 [9] Li K, Valla J, Garcia-Martinez J. Realizing the commercial potential of hierarchical zeolites: New opportunities in catalytic cracking[J]. Chem Cat Chem, 2014,6(1):67−81. [10] Li J, Wei Z, Chen Y, et al. A route to form initial hydrocarbon pool species in methanol conversion to olefins over zeolites[J]. Journal of Catalysis, 2014,317:277−283. doi: 10.1016/j.jcat.2014.05.015 [11] Sun X Y, Mueller S, Shi H, et al. On the impact of co-feeding aromatics and olefins for the methanol-to-olefins reaction on HZSM-5[J]. Journal of Catalysis, 2014,314:21−31. doi: 10.1016/j.jcat.2014.03.013 [12] Kim Y, Kim K, Ryoo R. Cooperative structure direction of diammonium surfactants and sodium ions to generate MFI zeolite nanocrystals of controlled thickness[J]. Chemistry of Materials, 2017,29(4):1752−1757. doi: 10.1021/acs.chemmater.6b05338 [13] Kyungsu N, Minkee C, Woojin P, et al. Pillared MFI zeolite nanosheets of a single-unit-cell thickness[J]. Journal of the American Chemical Society, 2010,132(12):4169−4177. doi: 10.1021/ja908382n [14] Akyalcin S, Akyalcin L, Bjørgen M. Optimization of desilication parameters of low-silica ZSM-12 by Taguchi method[J]. Microporous and Mesoporous Materials, 2019,273(1):256−264. [15] Abelló S, Bonilla A, Pérez-Ramírez J. Mesoporous ZSM-5 zeolite catalysts prepared by desilication with organic hydroxides and comparison with NaOH leaching[J]. Applied Catalysis a General, 2009,364(1-2):191−198. doi: 10.1016/j.apcata.2009.05.055 [16] Zhang P, Li S Q, Guo P H, et al. Synthesis of ZSM-5 microspheres made of nanocrystals from iron ore tailings by the solid phase conversion method[J]. Langmuir, 2020,36:6160−6168. doi: 10.1021/acs.langmuir.0c00570 [17] Ren L M, Wu Q M, Yang C G, et al. Solvent-free synthesis of zeolites from solid raw materials[J]. J. Am. Chem. Soc., 2012,134:15173−15176. doi: 10.1021/ja3044954 [18] Kamimura Y, Itabashi K J, Okubo T. Seed-assisted, OSDA-free synthesis of MTW-type zeolite and ‘‘Green MTW’’ from sodium aluminosilicate gel systems[J]. Microporous and Mesoporous Materials, 2012,147:149−156. doi: 10.1016/j.micromeso.2011.05.038 [19] Zhang C Q, Li S Q, Bao S C. Sustainable synthesis of ZSM-5 zeolite from rice husk ash without addition of solvents[J]. Waste and Biomass Valorization, 2019,10:2825−2835. doi: 10.1007/s12649-018-0356-0 -
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