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Rouchalová K, Rouchalová D, Čablík V, Matýsek D. Microwave-Assisted Hydrothermal Synthesis of Pure-Phase Sodalite (>99 wt.%) in Suspension: Methodology Design and Verification. MATERIALS (BASEL, SWITZERLAND) 2024; 17:269. [PMID: 38204121 PMCID: PMC10780149 DOI: 10.3390/ma17010269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 12/30/2023] [Accepted: 01/02/2024] [Indexed: 01/12/2024]
Abstract
Despite numerous studies focused on the hydrothermal (HT) synthesis of fly ash zeolites (FAZs), this method still has many limitations, the main of which is the low yield of zeolites. Hydrothermally synthesized zeolites are typically multiphase and exhibit low purity, which limits their applicability. Pure-phase zeolites have been primarily prepared from filtrates after alkaline mineralization of fly ashes, not directly in suspension. In addition, the published methodologies have not been tested in a wider set of samples, and thus their reproducibility is not confirmed. The aim of the study is to propose a reproducible methodology that overcomes the mentioned limitations. The influence of the Si/Al ratio (1.3:1-1:2), the type and concentration of the activator (2/4 M NaOH/KOH/LiOH), the reagent (30% LiCl), the duration (24-168 h), and the temperature (50-180 °C) of the synthesis phases were studied. The sequence of the synthesis phases was also optimized, depending on the type of heat transfer. The fly ashes were analyzed by wavelength-dispersive X-ray fluorescence (WD XRF), flame atomic absorption spectrometry (F-AAS), and X-ray diffraction (XRD). The energy intensity of the synthesis was reduced through the application of unique microwave digestion technology. Both microwave and combined (microwave and convection) syntheses were conducted. FAZs were identified and quantified by XRD analysis. This study presents a three-stage (TS) hydrothermal synthesis of pure-phase sodalite in suspension. Sodalite (>99 wt.%) was prepared from nine fly ashes under the following conditions: I. microwave phase: 120 °C, 150 min, solid-to-liquid ratio (S/L) 1:5, Si/Al ratio 1:1.5, and 4 M NaOH; II. convection phase: 120 °C, 24 h, S/L 1:40, and the addition of 30 mL of 30% LiCl; and III. crystallization: 70 °C for 24 h. The formation of rhombododecahedral sodalite crystals was confirmed by scanning electron microscope (SEM) images.
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Affiliation(s)
- Kamila Rouchalová
- Department of Environmental Engineering, Faculty of Mining and Geology, VŠB—Technical University of Ostrava, 17 Listopadu 2172/15, 708 00 Ostrava-Poruba, Czech Republic; (D.R.); (V.Č.)
| | - Dana Rouchalová
- Department of Environmental Engineering, Faculty of Mining and Geology, VŠB—Technical University of Ostrava, 17 Listopadu 2172/15, 708 00 Ostrava-Poruba, Czech Republic; (D.R.); (V.Č.)
| | - Vladimír Čablík
- Department of Environmental Engineering, Faculty of Mining and Geology, VŠB—Technical University of Ostrava, 17 Listopadu 2172/15, 708 00 Ostrava-Poruba, Czech Republic; (D.R.); (V.Č.)
| | - Dalibor Matýsek
- Department of Geological Engineering, Faculty of Mining and Geology, VŠB—Technical University of Ostrava, 17 Listopadu 2172/15, 708 00 Ostrava-Poruba, Czech Republic;
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Ju T, Jiang J, Meng Y, Yan F, Xu Y, Gao Y, Aihemaiti A. An investigation of the effect of ultrasonic waves on the efficiency of silicon extraction from coal fly ash. ULTRASONICS SONOCHEMISTRY 2020; 60:104765. [PMID: 31539728 DOI: 10.1016/j.ultsonch.2019.104765] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 07/22/2019] [Accepted: 09/02/2019] [Indexed: 06/10/2023]
Abstract
Burning of coal accounts for an enormous proportion of the current energy supply, especially in developing countries. Burning of coal produces large amounts of coal fly ash, which causes serious environmental problems unless it is managed properly. Using chemical analysis, we found that coal fly ash could be a promising source of Si, Al, Ca and some rare earth elements, especially with the assistance of some measures such as ultrasound. In this study, we extracted silicon from coal fly ash using an alkaline dissolution strategy and investigated the effects of temperature and ultrasonic power on the efficiency of silicon extraction. During a 70 min reaction, the efficiency of silicon extraction increased markedly, from 9.41% to 34.96%, as the reaction temperature increased from 70 °C to 110 °C. With ultrasound assistance, ultrasonic waves enhanced the extraction of silicon at both 80 °C and 110 °C at 720 W ultrasound, increasing the efficiency of silicon extraction from 6.01% to 15.36% and from 34.96% to 54.42%, respectively. However, at 900 W ultrasonic power, extraction was slightly inhibited at both temperatures, causing a little decrease in efficiency.
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Affiliation(s)
- Tongyao Ju
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Jianguo Jiang
- School of Environment, Tsinghua University, Beijing 100084, China; Collaborative Innovation Center for Regional Environmental Quality, Tsinghua University, Beijing 100084, China.
| | - Yuan Meng
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Feng Yan
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Yiwen Xu
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Yuchen Gao
- School of Environment, Tsinghua University, Beijing 100084, China
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Shah BA, Oluyinka OA, Shah AV. Fly Ash Reuse as Mesoporous Ca- and Mg-Zeolitic Composites for the Seclusion of Aniline from Aqueous Solution. ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING 2018. [DOI: 10.1007/s13369-018-3596-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Zhang L, Xu Z. One-Pot Synthesis of GeAs Ultrafine Particles from Coal Fly Ash by Vacuum Dynamic Flash Reduction and Inert Gas Condensation. Sci Rep 2017. [PMID: 28623310 PMCID: PMC5473855 DOI: 10.1038/s41598-017-03398-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Ge-monopnictides (GeAs) plays critical role in high-tech industry, especially in the field of advanced optical devices and infrared. As a secondary material, coal fly ash could be further recycled to retrieve germanium and prepare GeAs material with high added values. Hence, the aim of this paper is to propose a one-pot synthesis that uses vacuum flash reduction and inert-gas consolidation method to prepare GeAs ultrafine particles. Germanium in coal fly ash can be successfully recycled; simultaneously, GeAs ultrafine particles were prepared. Separation principle and feasibility of this process was discussed. Temperature, carrier gas flow rate and system pressure were the major factors on formation, morphology and distribution of particle size of GeAs ultrafine particles. A three steps synthetic mechanism was clarified, namely, thermal rupture of coal fly ash and release of GeO2 and As2O3, the gas-solid phase reaction of GeO2, As2O3 and coke to generate metallic Ge and As in vacuum flash reduction. Meantime, GeAs were produced in the gas phase reaction. Finally, GeAs ultrafine particles were obtained by carrier gas condensation. In short, this research developed a practical and environment-friendly one-pot synthesis to recycle germanium in coal fly ash and prepare GeAs ultrafine particles with high added values.
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Affiliation(s)
- Lingen Zhang
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, People's Republic of China
| | - Zhenming Xu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, People's Republic of China.
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Mazumder NA, Rano R. An efficient solid base catalyst from coal combustion fly ash for green synthesis of dibenzylideneacetone. J IND ENG CHEM 2015. [DOI: 10.1016/j.jiec.2015.04.015] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Itskos G, Koutsianos A, Koukouzas N, Vasilatos C. Zeolite development from fly ash and utilization in lignite mine-water treatment. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.minpro.2015.04.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Kobayashi N, Fujimori A, Tanaka M, Piao G, Itaya Y. Study of Coal Gasification Using High Ash Fusion Temperature Coal in an Entrained Flow Gasifier. JOURNAL OF CHEMICAL ENGINEERING OF JAPAN 2015. [DOI: 10.1252/jcej.13we221] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | - Miku Tanaka
- Department of Chemical Engineering, Nagoya University
| | - Guilin Piao
- School of Energy and Mechanical Engineering, Nanjing Normal University
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Deng H, Ge Y. Formation of NaP zeolite from fused fly ash for the removal of Cu(ii) by an improved hydrothermal method. RSC Adv 2015. [DOI: 10.1039/c4ra15196h] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Fly ash with a Si : Al ratio of 3.63 has been converted to a zeolite of high Cu2+ sorption capacity using a fusion conversion process and an improved hydrothermal method.
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Affiliation(s)
- Hui Deng
- Department of Chemistry
- Chemical Engineering and Environmental Engineering
- Liaoning Shihua University
- Fushun 113001
- China
| | - Yan Ge
- Department of Chemistry
- Chemical Engineering and Environmental Engineering
- Liaoning Shihua University
- Fushun 113001
- China
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Li J, Zhuang X, Font O, Moreno N, Vallejo VR, Querol X, Tobias A. Synthesis of merlinoite from Chinese coal fly ashes and its potential utilization as slow release K-fertilizer. JOURNAL OF HAZARDOUS MATERIALS 2014; 265:242-52. [PMID: 24365875 DOI: 10.1016/j.jhazmat.2013.11.063] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 11/25/2013] [Accepted: 11/29/2013] [Indexed: 05/08/2023]
Abstract
This study focuses on the synthesis of merlinoite from Chinese coal fly ashes by KOH direct conversion method, with special emphasis on the application of synthetic merlinoite as fertilizer. These fly ashes were collected from two pulverized-coal combustion (PCC) power plants in Xinjiang, Northwest China. The synthesis results are influenced by fly ash characteristics and different synthesis conditions (KOH solution concentrations, activation temperature, time, and KOH/fly ash ratios). A high quality merlinoite-rich product was synthesized under optimal activation conditions (KOH concentration of 5M, activation temperature of 150°C, activation time of 8h and KOH/fly ash ratio of 2l/kg), with a cation exchange capacity (CEC) of 160cmolkg(-1). The synthetic merlinoite is proved to be an efficient slow release K-fertilizer for plant growth, indicating that it can be widely used for high-nutrient demanding crops growing in nutrient-limited soils and for large-area poor soil amendment in opencast coal mine areas around the power plants that will substantially grow with the increasing coal combustion in Xinjiang in the near future.
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Affiliation(s)
- Jing Li
- Key Laboratory of Tectonics and Petroleum Resources, China University of Geosciences, Ministry of Education, Wuhan 430074, China.
| | - Xinguo Zhuang
- Key Laboratory of Tectonics and Petroleum Resources, China University of Geosciences, Ministry of Education, Wuhan 430074, China
| | - Oriol Font
- Institute of Environmental Assessment and Water Research, CSIC, C/Jordi Girona 18-26, Barcelona 08034, Spain
| | - Natalia Moreno
- Institute of Environmental Assessment and Water Research, CSIC, C/Jordi Girona 18-26, Barcelona 08034, Spain
| | - V Ramon Vallejo
- Department of Plant Biology, Faculty of Biology, University of Barcelona, Av. Diagonal, 643, Barcelona 08028, Spain
| | - Xavier Querol
- Institute of Environmental Assessment and Water Research, CSIC, C/Jordi Girona 18-26, Barcelona 08034, Spain
| | - Aurelio Tobias
- Institute of Environmental Assessment and Water Research, CSIC, C/Jordi Girona 18-26, Barcelona 08034, Spain
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Moreno T, Querol X, Alastuey A, de la Rosa J, Sánchez de la Campa AM, Minguillón M, Pandolfi M, González-Castanedo Y, Monfort E, Gibbons W. Variations in vanadium, nickel and lanthanoid element concentrations in urban air. THE SCIENCE OF THE TOTAL ENVIRONMENT 2010; 408:4569-79. [PMID: 20599248 DOI: 10.1016/j.scitotenv.2010.06.016] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2010] [Revised: 06/15/2010] [Accepted: 06/16/2010] [Indexed: 05/20/2023]
Abstract
The emission of trace metal pollutants by industry and transport takes place on a scale large enough to alter atmospheric chemistry and results in measurable differences between the urban background of inhalable particulate matter (PM) in different towns. This is particularly well demonstrated by the technogenic release into the atmosphere of V, Ni, and lanthanoid elements. We compare PM concentrations of these metals in large datasets from five industrial towns in Spain variously influenced by emissions from refinery, power station, shipping, stainless steel, ceramic tiles and brick-making. Increased La/Ce values in urban background inhalable PM, due to La-contamination from refineries and their residual products (fuel oils and petcoke), contrast with Ce-rich emissions from the ceramic related industry, and clearly demonstrate the value of this ratio as a sensitive and reliable tracer for many point source emissions. Similarly, anomalously high V/Ni values (>4) can detect the influence of nearby high-V petcoke and fuel oil combustion, although the use of this ratio in urban background PM is limited by overlapping values in natural and anthropogenic materials. Geochemical characterisation of urban background PM is a valuable compliment to the physical monitoring of aerosols widely employed in urban areas, especially given the relevance of trace metal inhalation to urban health issues.
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Affiliation(s)
- Teresa Moreno
- Institute of Environmental Assessment and Water Research, IDAEA, CSIC, C/ Jordi Girona 18, 08034 Barcelona, Spain.
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Medina A, Gamero P, Querol X, Moreno N, De León B, Almanza M, Vargas G, Izquierdo M, Font O. Fly ash from a Mexican mineral coal I: Mineralogical and chemical characterization. JOURNAL OF HAZARDOUS MATERIALS 2010; 181:82-90. [PMID: 20546994 DOI: 10.1016/j.jhazmat.2010.04.096] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2009] [Revised: 04/16/2010] [Accepted: 04/22/2010] [Indexed: 05/28/2023]
Abstract
The properties of coal fly ash are strongly dependent on the geological origin and the combustion process of the coal. It is important to characterize regional fly ash in detail to ascertain its potential uses as raw material in the production of high value products. The physicochemical properties of fly ash coming from the "Jose Lopez Portillo" coal-fired power plant, Coahuila, Mexico (MFA), are presented in this work. A detailed study of trace elements, the chemical composition of the amorphous phase, thermal stability and the leaching of contaminant elements under different conditions are included. MFA is composed of mullite, quartz, calcite, magnetite and an amorphous phase. This material contains mainly silica (59.6%), alumina (22.8%) and magnetite (5.6%). Its amorphous phase (78.3%) has a high silica (49.4%) and alumina (14.4%) content. According to its mineralogical and chemical composition, MFA is potentially useful as a raw material for making cement, silica, and alumina, as well as low silica/alumina ratio zeolites. Deleterious elements could be removed during the zeolitization process or with an additional acid treatment. Because of its morphological properties and structural and thermal stability, MFA can be used in thermal isolation and refractory materials and as a support for heterogeneous catalysts.
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Affiliation(s)
- Adriana Medina
- CINVESTAV IPN-Unidad Saltillo, Ramos Arizpe, Coahuila, Mexico
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Medina A, Gamero P, Almanza JM, Vargas A, Montoya A, Vargas G, Izquierdo M. Fly ash from a Mexican mineral coal. II. Source of W zeolite and its effectiveness in arsenic (V) adsorption. JOURNAL OF HAZARDOUS MATERIALS 2010; 181:91-104. [PMID: 20537461 DOI: 10.1016/j.jhazmat.2010.04.102] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2009] [Revised: 04/24/2010] [Accepted: 04/26/2010] [Indexed: 05/29/2023]
Abstract
Coal-fired plants in Coahuila (Mexico) produce highly reactive fly ash (MFA), which is used in a one-step process as a raw material in producing zeolite. We explored two routes in the synthesis of zeolite: (a) direct MFA zeolitization, which resulted in the formation of W zeolite with KOH and analcime with NaOH and (b) a MFA fusion route, which resulted in the formation of zeolite W or chabazite with KOH and zeolite X or P with NaOH. No residual crystalline phases were present. When LiOH was employed, ABW zeolite with quartz and mullite were obtained. For both zeolitization routes, the nature of the alkali (KOH, NaOH, LiOH), the alkali/MFA ratio (0.23-1.46), and the crystallization temperature and time (90-175 degrees C; 8-24 h) were evaluated. Additionally, the effect of temperature and time on MFA fusion was studied. W zeolite was obtained by both zeolitization methods. The direct route is preferred because it is a straightforward method using soft reaction conditions that results in a high yield of low cost zeolites with large crystal agglomerates. It was demonstrated that aluminum modified W zeolite has the ability to remove 99% of the arsenic (V) from an aqueous solution of Na(2)HAsO(4).7H(2)O originally containing 740 ppb.
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Affiliation(s)
- Adriana Medina
- CINVESTAV IPN-Unidad Saltillo, Ramos Arizpe, Coahuila, Mexico
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