Porous silica synthesis out of coal fly ash with no residue generation and complete silicon separation

Ju, Tongyao; Han, Shuangfeng; Meng, Fanzhi; Li, Lin; Li, Jinglin; Chen, Kailun; Jiang, Jianguo

doi:10.1007/s11783-023-1712-2

Cited by 10 publications

(15 citation statements)

References 57 publications

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“…[35] At temperatures beyond the melting point of the additive, even the unreacted quartz will start to dissolve in the melt resulting in an increased reaction rate. [36] Ju [33] carried a similar study of crystal transformation or activation of the coal fly ash using sodium carbonate, the main crystalline phases obtained were sodium silicate (Na 2 SiO 3 ), nepheline (Na 2.8 K 0.6 Ca 0.2 Al 3.8 Si 4.2 O 16 ), and sodium aluminium oxide silicate (NaAlSiO 4 ) which are relatively like phases in figure 4. Zhou et al [37] investigated the phase change process during calcination and confirmed that different sodium silicates and nephelines are the most stable primary products following the calcination.…”

Section: Characterization Of Cfa-cal-na 2 Co 3 -900 °C-3 Hrs-15mentioning

confidence: 99%

“…After filtration with water and drying, the sample turned brown. [33] The initial temperature of 900 °C was used as a reference point for investigating two additional factors: the duration of the process and the proportion of Na 2 CO 3 to CFA. Following that, the optimal parameters (for higher Si/Al ratio) were determined to be a temperature of 900 °C, a length of 3 hours, and a ratio of CFA to Na 2 CO 3 of 1 : 1.5.…”

Section: Mineral Phase Transitions At Various Calcination Temperaturesmentioning

confidence: 99%

“…[52] At this point, or beyond the relative pressure threshold where no evaporation occurs from the porous system already saturated with the condensed phase. [53] Ju et al [33] carried out the same study with and without the structure directing agent, CTAB. Without the structure-directing agent, the synthesized silica was found to be non-porous as the BJH plot had no peak and was porous with the structure-directing agent, CTAB.…”

Section: Bet Analysismentioning

confidence: 99%

See 2 more Smart Citations

High‐Purity Template‐Free Mesoporous Silica Synthesized FROM Coal Fly Ash

Manyepedza,

Gaolefufa,

Beas

et al. 2024

ChemistrySelect

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The study demonstrates a new method to create high‐purity mesoporous silica from coal fly ash without using structure‐directing agents. Divided into two stages, the process involves pre‐treating the ash with Na2CO3, calcination, cooling, washing, and drying to yield a dehydrated sample. Subsequently, silica synthesis occurs through an acid refluxing technique using thermally activated coal fly ash with Na2CO3. Key factors impacting synthesis include acid content and liquid‐to‐solid ratio. The study extensively employs various characterization methods like XRF, XRD, FTIR, and BET analysis, revealing a 99.1 % purity in silica content, a surface area of 793.51 m2/g, and a pore size of 3.9 nm. Optimal conditions for this synthesis involve 80 °C temperature, 2‐hour reaction time, 25 % hydrochloric acid concentration, and a 10 : 1 liquid‐to‐solid ratio. FTIR spectra demonstrate similarities between the obtained silica and commercial Sigma Aldrich silica. This innovative approach presents a promising avenue for generating top‐quality silica from coal fly ash, potentially diversifying applications across industries reliant on high‐performance silica materials.

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Section: Characterization Of Cfa-cal-na 2 Co 3 -900 °C-3 Hrs-15mentioning

confidence: 99%

Section: Mineral Phase Transitions At Various Calcination Temperaturesmentioning

confidence: 99%

Section: Bet Analysismentioning

confidence: 99%

See 1 more Smart Citation

High‐Purity Template‐Free Mesoporous Silica Synthesized FROM Coal Fly Ash

Manyepedza,

Gaolefufa,

Beas

et al. 2024

ChemistrySelect

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“…The utilization of FA for the synthesis of SA can effectively mitigate its adverse environmental impact, minimize resource wastage, and lower production costs. 29 In this study, we applied a facile synthetic method to prepare silica−chitosan composite aerogels (SCA) using FA as a silica source. Chitosan with anisotropic morphology was used as a frame to modulate the backbone and microstructure of SA to enhance its mechanical properties.…”

Section: Introductionmentioning

confidence: 99%

“…Furthermore, FA has abundant reserves, stable sources, and a high silicon content, making it a cost-effective silicon source with significant potential. The utilization of FA for the synthesis of SA can effectively mitigate its adverse environmental impact, minimize resource wastage, and lower production costs . In this study, we applied a facile synthetic method to prepare silica–chitosan composite aerogels (SCA) using FA as a silica source.…”

Section: Introductionmentioning

confidence: 99%

Nanoporous Silica–Chitosan Aerogels for Thermal Insulation and Flame Retardancy

Zhuo,

Chen,

Xie

et al. 2024

ACS Appl. Nano Mater.

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The significant accumulation of fly ash has resulted in serious environmental issues. It is imperative to find a safe and high-value method for reusing fly ash to effectively address this problem. Additionally, silica aerogels have gained attention as a promising material for energy conservation and thermal management. However, producing a silica aerogel with low production costs and superior overall properties is still a major challenge. In this study, silica−chitosan composite aerogels (SCA) were prepared from fly ash and chitosan. Amorphous silica is polymerized in situ on chitosan by hydrogen bonding and silyloxygen condensation. The resulting aerogels exhibited a fully formed block structure, extremely low density, exceptional flame retardancy, and notable mechanical properties (able to withstand 24,000 times the stress of its own mass). It is noteworthy that the nanopores and three-dimensional network structure endow SCA with excellent thermal insulation performance (with a thermal conductivity of 0.0474−0.0521 W m −1 K −1 ). The strategy presented here provides a cost-effective and straightforward approach to prepare SCA. The results demonstrate its considerable potential for practical use in energy-efficient and thermally insulated structures. Moreover, this approach offers a direct and high value-added solution to the problem of fly ash.

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Solid‐phase synthesis of silicalite‐1 molecular sieve based on fly ash and its CO₂ adsorption performance

Wu,

Nulahong,

Miao

et al. 2024

Greenhouse Gases

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In this work, an alkali melting‐pickling assisted solid phase synthesis method of S‐1 zeolite molecular sieve with excellent adsorption properties for CO2 was successfully developed by using solid waste fly ash. SiO2 with a purity of up to 97.84% was successfully extracted by using alkaline fusion activation, high temperature calcination and pickling. The CO2 adsorption capacity of the prepared SiO2 was 0.51 mmol/g at 298 K and 1 bar. Silicalite‐1 molecular sieve was prepared by solid phase synthesis method using SiO2 extracted from fly ash as silicon source. The results showed that the prepared Silicalite‐1 had good morphology and relatively high crystallinity. The specific surface area is 623.30 m2/g, and the total pore volume is 0.31 cm3/g. In addition, the adsorption capacity of CO2 was 2.05 mmol/g at 298 K and 1 bar. Compared with the prepared SiO2, the adsorption capacity of CO2 by Silicalite‐1 molecular sieve increased by four times. Moreover, under the test condition of 298 K, it has a high selectivity coefficient for CO2/N2 mixed gas, and after 10 times of adsorption‐desorption cycle tests, the adsorption capacity of Silicalite‐1 molecular sieve for CO2 does not change significantly, and its adsorption rate can still be as high as 89.31%. The results indicate that Silicalite‐1 molecular sieve prepared by solid phase synthesis method has good adsorption selectivity and adsorption–desorption cycle regeneration stability, and can be used in the field of CO2 adsorption, separation and purification. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.

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Porous silica synthesis out of coal fly ash with no residue generation and complete silicon separation

Cited by 10 publications

References 57 publications

High‐Purity Template‐Free Mesoporous Silica Synthesized FROM Coal Fly Ash

High‐Purity Template‐Free Mesoporous Silica Synthesized FROM Coal Fly Ash

Nanoporous Silica–Chitosan Aerogels for Thermal Insulation and Flame Retardancy

Solid‐phase synthesis of silicalite‐1 molecular sieve based on fly ash and its CO₂ adsorption performance

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Porous silica synthesis out of coal fly ash with no residue generation and complete silicon separation

Cited by 10 publications

References 57 publications

High‐Purity Template‐Free Mesoporous Silica Synthesized FROM Coal Fly Ash

High‐Purity Template‐Free Mesoporous Silica Synthesized FROM Coal Fly Ash

Nanoporous Silica–Chitosan Aerogels for Thermal Insulation and Flame Retardancy

Solid‐phase synthesis of silicalite‐1 molecular sieve based on fly ash and its CO2 adsorption performance

Contact Info

Product

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Solid‐phase synthesis of silicalite‐1 molecular sieve based on fly ash and its CO₂ adsorption performance