Synthesis and Characterization of Cordierite, Mullite and Cordierite-Mullite Ceramic Materials using Coal Fly Ash as Raw Material

MRS Advances ◽  
2017 ◽  
Vol 2 (62) ◽  
pp. 3865-3872
Author(s):  
J. López-Cuevas ◽  
E. Interial-Orejón ◽  
C.A. Gutiérrez-Chavarría ◽  
J.C. Rendón-Ángeles
Keyword(s):  
Fly Ash ◽  
Flexural Strength ◽  
Vickers Microhardness ◽  
Coal Fly Ash ◽  
Ceramic Materials ◽  
Raw Material ◽  
X Ray Diffraction ◽  
Mullite Ceramic ◽  
Two Temperatures

AbstractCordierite (Mg2Al4Si5O18), Mullite (Al4+2xSi2-2xO10-x) and Cordierite-Mullite ceramic materials were obtained from a stoichiometric mixture of coal fly ash (CFA) as a source of SiO2 and Al2O3, plus high-purity MgO and Al2O3. The starting stoichiometric mixtures were homogenized, and then uniaxially pressed, cold isostatically pressed, and sintered at 1200-1600 °C for 2-5 h. The sintered materials were characterized by X-ray diffraction, scanning electron microscopy, Vickers microhardness, density and four-point flexural strength. In general, the desired phases tended to form in the composites at temperatures of 1350 or 1400 °C, with a considerable amount of glassy phase developing from 3 h onwards at one of those two temperatures, depending on the composite composition. The microstructure of the composites consisted of a matrix of Cordierite and interwoven needles of Mullite. The bulk density decreased, while the flexural strength and the Vickers microhardness increased with increasing nominal content of Mullite in the composites. A synergistic effect taking place between Cordierite and Mullite enhances the mechanical properties of the composites.

scholarly journals Synergistic Sintering of Lignite Fly Ash and Steelmaking Residues towards Sustainable Compacted Ceramics

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
V. G. Karayannis ◽  
A. K. Moutsatsou ◽  
A. N. Baklavaridis ◽  
E. L. Katsika ◽  
A. E. Domopoulou
Keyword(s):  
Fly Ash ◽  
Sintering Temperature ◽  
Value Added ◽  
Mineralogical Composition ◽  
Ceramic Materials ◽  
Raw Material ◽  
Processing Temperature ◽  
Lignite Fly Ash ◽  
Experimental Findings

The development of value-added ceramic materials deriving only from industrial by-products is particularly interesting from technological, economic, and environmental point of views. In this work, the synergistic sintering of ternary and binary mixtures of fly ash, steelmaking electric arc furnace dust, and ladle furnace slag for the synthesis of compacted ceramics is reported. The sintered specimens’ microstructure and mineralogical composition were characterized by SEM-EDS and XRD, respectively. Moreover, the shrinkage, apparent density, water absorption, and Vickers microhardness (HV) were investigated at different sintering temperatures and raw material compositions. The characterization of the sintered compacts revealed the successful consolidation of the ceramic microstructures. According to the experimental findings, the ceramics obtained from fly ash/steel dust mixtures exhibited enhanced properties compared to the other mixtures tested. Moreover, the processing temperature affected the final properties of the produced ceramics. Specifically, a 407% HV increase for EAFD and a 2221% increase for the FA-EAFD mixture were recorded, by increasing the sintering temperature from 1050 to 1150°C. Likewise, a 972% shrinkage increase for EAFD and a 577% shrinkage increase for the FA-EAFD mixture were recorded, by increasing the sintering temperature from 1050 to 1150°C. The research results aim at shedding more light on the development of sustainable sintered ceramics from secondary industrial resources towards circular economy.

scholarly journals Effects of Kaolin Additives in Fly Ash on Sintering and Properties of Mullite Ceramics

Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 887
Author(s):  
Marta Valášková ◽  
Veronika Blahůšková ◽  
Jozef Vlček
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Bulk Density ◽  
Porous Ceramics ◽  
Raw Material ◽  
X Ray Diffraction ◽  
Effective Utilization ◽  
Sintering Properties ◽  
Mullite Ceramics

The effective utilization of fly ash (FA) as a raw material for ceramics production is performed on the FA-kaolin mixtures containing kaolins 10% by mass. The mixtures in comparison with FA and three raw kaolins were annealed to mullite ceramics at temperatures of 1000, 1100, 1200 and 1300 °C. The main aims were to contribute to the discussion on the effect of impurity of Na,K-feldspars in kaolins and Fe2O3 in FA on sintering procedure, porous ceramics properties and mullite structural properties. The phases were characterized using X-ray diffraction and thermogravimetry DTA/TGA methods. Mercury intrusion porosimetry was used for characterization of porosity of ceramic samples. Results evidenced the influence of feldspars in kaolins and Fe2O3 in FA on the sintering temperatures and properties of mullite ceramics. The fully FA-based ceramic sintered at 1100 °C exhibited post-sintering properties of bulk density 2.1 g/cm3; compressive strength 77.5 MPa; and porosity, 2% in comparison with the FA/kaolin-based ceramics properties of bulk density 2.2 g/cm3; compressive strength, 60–65 MPa; and porosity from 9.3 to 16.4% influenced by Na,K-feldspars. The best structural and mechanical characteristics were found for the FAK3 sample, supported by the high content of kaolinite and orthoclase in the kaolin K3 additive. The FAK3 annealed at 1100 °C exhibited good compressive strength of 87.6 MPa at a porosity of 10.6% and density of 2.24 g/cm3 and annealed at 1300 °C the compressive strength of 41.3 MPa at a porosity of 19.2% and density of 1.93 g/cm3.

scholarly journals Extraction of Al-Si master alloy and alumina from coal fly ash

2017 ◽  
Vol 53 (2) ◽  
pp. 155-162 ◽  
Author(s):  
A. Liu ◽  
Z. Shi ◽  
K. Xie ◽  
X. Hu ◽  
B. Gao ◽  
...  
Keyword(s):  
Fly Ash ◽  
Master Alloy ◽  
Power Plants ◽  
Coal Fly Ash ◽  
Raw Material ◽  
Aluminothermic Reduction ◽  
Chemical Compositions ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray

Coal fly ash from coal power plants is a potential raw material for the production of alumina. An objective aluminothermic reduction method for the preparation of Al-Si master alloy and alumina from coal fly ash was investigated. The kinetic analysis using non-isothermal differential scanning calorimetry indicated that the reduction of Al6Si2O13, Fe2O3, and TiO2 by aluminum in coal fly ash occurs at 1618 K, 1681 K, and 1754 K, respectively. Moreover, the influence of reaction temperature on product composition was studied. The phases and morphologies of the products obtained by the aluminothermic reduction of coal fly ash at 1373-1773 K were analyzed by X-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy, respectively. The results from X-ray diffraction show that no oxide reduction has taken place at 1373 K and 1473K, the compositions of the product obtained by aluminothermic reduction of fly ash at 1573K- 1673 K are Al2O3, mullite, Al and Si, while the compositions of the product at 1773 K are Al2O3, Al, and Si. In addition, the chemical compositions of Al-Si alloy obtained at 1773 K are 86.81 wt% Al and 13.19 wt% Si.

Quality Characterization of Iron Dust Exhaust Thermal as Alternative Ceramic Coating Raw Materials in a Brazilian Company

2014 ◽  
Vol 1077 ◽  
pp. 135-138
Author(s):  
Luiz Oliveira Veriano dalla Valentina ◽  
Marilena Valadares Folgueras ◽  
Wanessa Rejane Knop ◽  
Maria Cristina Pacheco do Nascimento ◽  
Glaucia Aparecida Prates
Keyword(s):  
Ceramic Coating ◽  
Raw Materials ◽  
Ceramic Materials ◽  
Raw Material ◽  
Silica Sand ◽  
Commercial Application ◽  
X Ray Diffraction ◽  
X Ray ◽  
Materials Used

As the raw materials used in the ceramic materials manufacturing are natural, it is important to use them as a alternative materials, thus decreasing the elements demand taken from nature. This paper aims the characterization of foundry solid powder exhaust from a brazilian company located in Joinville - SC as an alternative raw material for ceramic coating by X-ray diffraction (XRD), thermal analysis (DSC) and thermogravimetric (TG). The dust depletion is caused in the manufacturing mold sand process, when the bentonita (clay), silica sand and coal during the metal parts production are mixed in green sand production. The raw materials were characterized through X-ray diffraction (XRD), thermal (DSC) and thermogravimetric analisys (TG). The atomized powder thermogravimetric analysis curve shows three intervals associated with the mass loss and it is typical of clay commercial application.

scholarly journals Dynamic hydrothermal synthesis of xonotlite fibers by alkali silica extraction of fly ash

2019 ◽  
Vol 14 ◽  
pp. 155892501989034 ◽  
Author(s):  
Xu Peng
Keyword(s):  
Fly Ash ◽  
Hydrothermal Synthesis ◽  
Coal Fly Ash ◽  
Synthesis Method ◽  
Morphological Characteristics ◽  
Mineralogical Composition ◽  
Raw Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
Silica Material

The silica leached from coal fly ash using alkali, via the hydrothermal method, can be used as the raw material for the synthesis of xonotlite fibers through the hydrothermal synthesis method. This investigation was made to examine how the fly ash desilicated liquid influences the crystal growth and microstructure of xonotlite fibers. The obtained samples were characterized by X-ray diffraction and scanning electron microscope techniques to investigate their mineralogical composition and morphological characteristics. The results indicated that the pure desilication liquid leached from coal fly ash could be used to prepare xonotlite fibers. Xonotlite fibers with single crystal characteristics and large aspect ratio of 100–400 were successfully fabricated from fly ash desilication liquid, which is used as the silica material, at 240°C for 6 h.

scholarly journals Synthesis of ZSM-5 Zeolite Using Coal Fly Ash as an Additive for the Methanol to Propylene (MTP) Reaction

Catalysts ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 788 ◽  
Author(s):  
Rui Feng ◽  
Kening Chen ◽  
Xinlong Yan ◽  
Xiaoyan Hu ◽  
Yixin Zhang ◽  
...  
Keyword(s):  
Fly Ash ◽  
Coal Gasification ◽  
Coal Fly Ash ◽  
Strong Acid ◽  
Acid Sites ◽  
Raw Material ◽  
X Ray Diffraction ◽  
Strong Acid Sites ◽  
Optimized Conditions ◽  
N2 Sorption

Using ZSM-5 zeolites as catalysts for the methanol to propylene (MTP) reaction is being widely investigated and has been industrially applied. In this study, pure ZSM-5 zeolite was successfully synthesized by a direct hydrothermal method using the fly ash of coal gasification as an additional raw material. Various analysis methods such as X-ray diffraction, N2 sorption, scanning electron microscopy, and infrared spectroscopy, were employed to characterize the physicochemical properties of parent and modified zeolites. Then, the prepared ZSM-5 catalysts were tested in the MTP reaction. The results showed that pure ZSM-5 could be directly synthesized in the optimized conditions using fly ash as additional silicon and aluminum sources, and those ZSM-5 catalysts turned out to be candidate catalysts for the MTP reaction. Whereas their catalytic lifetimes were not good enough due to the strong acid sites and needed improving.

Effect of Potassium Carbonate Addition on the Sintered Properties of Coal Fly Ash

2014 ◽  
Vol 602-603 ◽  
pp. 230-233 ◽  
Author(s):  
Wen Li ◽  
Bing Bing Fan ◽  
Bing Bing Wang ◽  
Bing Sun ◽  
Liang Zhang ◽  
...  
Keyword(s):  
Fly Ash ◽  
Potassium Carbonate ◽  
Sintering Temperature ◽  
Coal Fly Ash ◽  
Ceramic Materials ◽  
Aluminum Silicate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dense Ceramic ◽  
Electronic Microscope

In this project, coal fly ash was transformed into ceramic materials by adding a certain amount of fusing agent. Ash samples were compacted and sintered with the addition of potassium carbonate (K2CO3·1/2H2O) under a suitable sintering temperature range. Mineralogy and microstructure of the obtained products were characterized by means of X-ray diffraction and field emission scanning electronic microscope techniques respectively. The results indicate that K2CO3·1/2H2O facilitates the transformation of mullite and quartz phases above 800°C, and the mineralogy phases of the product is leucite (KAlSi2O6) and potassium aluminum silicate (KAlSiO4). In the process, K+interacts with oxygen atom and destroys the original lattice. The regular morphology of the sintered samples was confirmed by the observation under SEM, which reveals a uniform dense ceramic is formed at 900°C with the 40wt% addition of K2CO3·1/2H2O.

Synthesis and characterization of coal fly ash supported zinc oxide catalyst for biodiesel production using used cooking oil as feed

2021 ◽  
Vol 170 ◽  
pp. 302-314
Author(s):  
Adeyinka S. Yusuff ◽  
Aman K. Bhonsle ◽  
Jayati Trivedi ◽  
Dinesh P. Bangwal ◽  
Lok P. Singh ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Fly Ash ◽  
Oxide Catalyst ◽  
Coal Fly Ash ◽  
Biodiesel Production ◽  
Synthesis And Characterization ◽  
Cooking Oil ◽  
Used Cooking Oil
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