Synthesis of CFB-Coal Fly Ash Clay Bricks and Their Characterisation

This study analyzed the last 20 years` data available on power plant coal ashes used in clay brick production. The statistical analysis has been carried out for a total of 302 cases based on the relevant parameters reported in the literature. The chemical composition of the clays and coal ashes, percentage incorporation and maximum particle size of ash, size of fired samples, peak firing temperature, and the corresponding soaking time were selected as inputs for modeling. The product characteristics i.e. open porosity, water absorption, and compressive strength was taken as output parameters. An artificial neural network model has been developed and showed a satisfactory fit to experimental data and predicted the observed output variables with the overall coefficient of determination (r2) of 0.972 during the training period. Besides, the reduced chi-square, mean bias error, root mean square error, and mean percentage error were utilized to check the correctness of the obtained model, which proved the network generalization capability. The sensitivity analysis of the model suggested that the quantity of Na2O coming from brick clays, the percentages of SiO2 and K2O coming from ashes, and MgO coming from clays were the most influential parameters in descending order for the ash-clay composite bricks` quality, mostly owing to the influence of fluxes during firing.

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“…1). This indicated that class F ashes are more favorable to be used in the brick industry, which is already observed earlier [21].…”

Section: Global Sensitivity Analysissupporting

confidence: 75%

“…The study considered the 302 cases available in the literature on the usage of fly [1,[3][4][5][7][8][9][10][11][12][13][14][15][18][19][20][21][22][23][24][25][26][27][28][29][30], bottom ashes [2,6,24,30], and pond ashes [5,13,14,31] in clay bricks.…”

Section: Materials and Experimental Proceduresmentioning

confidence: 99%

An artificial neural network-based prediction model for utilization of coal ash in production of fired clay bricks: A review

et al. 2021

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“…Water absorption of diff erently shaped samples was evaluated in fired clay pieces by soaking in distilled water for 24 hours, according to standard procedure [12].…”

Section: Chemical and Technological Featuresmentioning

confidence: 99%

Prediction and Optimization of Heavy Clay Products Quality

Arsenović

Pezo

Mančić

et al. 2014

Advanced Materials for Agriculture, Food, and Environmental Safety

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Th e eff ects of chemical composition, fi ring temperature (800-1100 °C), and several shape formats of laboratory brick samples on the fi nal product quality were investigated. Prediction of the fi nal laboratory products parameters was evaluated by second order polynomial regression models (SOPs) and artifi cial neural networks (ANNs), and aft erwards compared to experimental results. SOPs showed high r 2 values (0.897-0.913 for compressive strength models, 0.942-0.962 for water absorption, 0.928 for fi ring shrinkage, 0.988-0.991 for water loss during fi ring, and 0.941 for volume mass of cubes models). An ANN model, coupled with sensitivity analysis, was obtained with high prediction accuracy: 0.866-0.939 for compressive strength models, 0.954-0.974 for water absorption, 0.882 for fi ring shrinkage, 0.982-0.988 for water loss during fi ring, and 0.920 for volume mass of cubes models. Th e optimal samples' chemical composition and fi ring temperature were chosen depending on a fi nal usage of the raw material in heavy clay brick industry.

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“…Fly ash can be considered as the world's fifth largest raw material resource [7]. Currently, one possible utilization of fly ash is in the synthesis of alkali-activated materials named geopolymers [8,9]. PC fly ash can successfully be used for the manufacturing of cement, building materials concrete, and concrete-admixed products [10], as it is categorized as a pozzolan, while CFB fly ash with a higher carbon content is broadly used as an insulator and adsorbent [6,11].…”

Section: Introductionmentioning

confidence: 99%

Structural Characterizations of Aluminosilicates in Two Types of Fly Ash Samples from Shanxi Province, North China

et al. 2019

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In order to determine the structural characterization of aluminosilicates in two types of fly ashes, two samples from Shanxi Province, China were selected for study. One was from a pulverized coal boiler (FA-1), and the other from a circulating fluidized bed boiler (FA-2). FA-1 had a much higher content of silicon dioxide (SiO2) (70.30%) than FA-2(42.19%), but aluminum oxide (Al2O3) was higher in FA-2 (25.41%) than in FA-1 (17.04%). The characterizations were investigated using various methods including X-ray diffraction (XRD), Fourier transform infrared spectrometry (FTIR), magic angle spinning nuclear magnetic resonance (MAS–NMR) spectrometry, and X-ray photoelectron spectroscopy (XPS). The XRD analysis showed that FA-1 contained aluminosilicate glass, quartz and mullite, while FA-2 contained significant amounts of amorphous aluminosilicate, quartz and gypsum. The FTIR results showed an increased substitution of Al3+ for Si4+ as the band of asymmetric stretching vibrations Si–O(Si) (1100 cm−1) moved to 1090 cm−1 for FA-2, much lower than for FA-1(1097 cm−1). Moreover, the sharpness of the bands in the 1250–1000 cm−1 region for FA-2 indicates that the silicate structure of FA-2 was more ordered than for FA-1. It can be understood from the 29Si MAS–NMR results that Q4(mAl) (Q4 are connected via 4 bridging O atoms to mAl) is the main structural type in FA-1 and FA-2, and that FA-2 contains more Al, which substitutes for Si in the Q4 structure. 27Al MAS–NMR demonstrated that a combination of tetrahedral, pentahedral, and octahedral Al existed in FA-1 and FA-2. The Si 2p XPS spectra suggested that there were three forms of Si, including bridging Si (Si–O2), non–bridging Si (Si–O), and SiO2 gel. The content of Si–O2 for FA-1 was 37.48% higher than Si–O (28.57%), while the content of Si–O2 was 30.21% lower than Si–O (40.15%) for FA-2. The Al 2p XPS spectra showed that octahedral Al was the dominant form for FA-1 with a content of 40.25%, while the main phase was tetrahedral Al for FA-2 with a proportion of 37.36%, which corresponds well with the 27Al MAS–NMR results.

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Synthesis of CFB-Coal Fly Ash Clay Bricks and Their Characterisation

Cited by 31 publications

References 23 publications

An artificial neural network-based prediction model for utilization of coal ash in production of fired clay bricks: A review

An artificial neural network-based prediction model for utilization of coal ash in production of fired clay bricks: A review

Prediction and Optimization of Heavy Clay Products Quality

Structural Characterizations of Aluminosilicates in Two Types of Fly Ash Samples from Shanxi Province, North China

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