Phase Evolution and Sintering Characteristics of Mullite-Based Ceramics Prepared from Coal Fly Ash, Calcined Bauxite and Ball Clay

2009 ◽  
Vol 79-82 ◽  
pp. 2019-2022 ◽  
Author(s):  
Xue Ma ◽  
Xiao Yao ◽  
Su Dong Hua

The study provides a novel way for the utilization of coal fly ash, and enriches the sintering mechanism in preparation of low-cost, high performance mullite based ceramic. The phase evolution, microstructure, densification behavior and flexural strength as a function of the sintering temperatures, were investigated by XRD, SEM and evaluated by density, open porosity and shrinkage and three point bending method, respectively. Secondary mullite nucleates from the dissolution of alumina in transient liquid phase at 1300°C. Above 1400°C, mullite content increases and the densification is promoted with increasing temperature. Fast densification takes place and high flexural strength of 149MPa is achieved at 1600°C.

Author(s):  
Virendra Kumar Yadav ◽  
R Suriyaprabha ◽  
Gajendra Kumar Inwati ◽  
Nitin Gupta ◽  
Bijendra Singh ◽  
...  

Membranes ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 711
Author(s):  
Wan Fan ◽  
Dong Zou ◽  
Jingrui Xu ◽  
Xianfu Chen ◽  
Minghui Qiu ◽  
...  

Support is a necessary foundation for ceramic membranes to achieve high performance. Finding the optimum balance between high performance and low cost is still a significant challenge in the fabrication of ceramic supports. In this study, low-cost fly ash-based ceramic supports with enhanced performance were prepared by the addition of bauxite. The pore structure, mechanical strength, and shrinkage of fly ash/bauxite supports could be tuned by optimizing the bauxite content and sintering temperature. When the sintering temperature and bauxite content were controlled at 1300 °C and 40 wt%, respectively, the obtained membrane supports exhibited a high pure water permeance of approximately 5.36 m3·m−2·h−1·bar−1 and a high bending strength of approximately 69.6 MPa. At the same time, the optimized ceramic supports presented a typical mullite phase and excellent resistance to acid and alkali. This work provides a potential route for the preparation of ceramic membrane supports with characteristics of low cost and high performance.


2018 ◽  
Vol 154 ◽  
pp. 01037 ◽  
Author(s):  
Agus Taufiq ◽  
Pratikno Hidayat ◽  
Arif Hidayat

The removal of reactive dyes on modified coal fly ash has been investigated during a series of batch adsorption experiments. Physical characteristics of modified coal fly ash was characterized by Brunauer Emmett Teller (BET) surface area analysis, X-ray powder diffraction (XRD), Fourier transform infrared spectrophotometer (FT-IR), and scanning electron microscope (SEM). The effects of operational parameters such as initial dye concentration (50–200 mg/L), solution pH (4–10) and adsorbent dosage (50–200 mg/L) were studied. The adsorption experiments indicated that modified coal fly ash was effective in removing of Remazol Blue. The percentage removal of dyes increased while the modified fly ash dosage increased. The percentage removal of dyes increased with decreased initial concentration of the dye and also increased with amount of adsorbent used. The optimum of removal of dyes was found to be 94% at initial dye concentration 50 g/mL, modified fly ash dosage 250 g/mL, and pH of 2.0.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Marinela Barbuta ◽  
Emanuela Marin ◽  
Sorin Mihai Cimpeanu ◽  
Gigel Paraschiv ◽  
Daniel Lepadatu ◽  
...  

The influence of coal fly ash and glass fiber waste on the tensile strength of cement concrete was studied using central composite design. Coal fly ash was used to replace 10% of the cement in the concrete mix. Glass fiber was added to improve the tensile properties of the concrete in different dosages and lengths. In total, 14 mixes were investigated, one only with 10% coal fly ash replacement of cement and the other thirteen were determined by the experimental design. Using analysis of variance, the order of importance of the variables was established for each property (flexural strength and split tensile strength). From the nonlinear response surfaces, it was found that higher values of flexural strength were obtained for fibers longer than 12 mm and at a dosage of 1-2%. For split tensile strength, higher values were obtained for fibers with a length of 19–28 mm and at a dosage of 1–1.5%.


2015 ◽  
Vol 121 ◽  
pp. 961-966 ◽  
Author(s):  
Xiaotong Jin ◽  
Na Ji ◽  
Chunfeng Song ◽  
Degang Ma ◽  
Guoping Yan ◽  
...  
Keyword(s):  
Fly Ash ◽  
Low Cost ◽  

2017 ◽  
Vol 5 (1) ◽  
pp. 391-399 ◽  
Author(s):  
Mahshid Attari ◽  
Syed Salman Bukhari ◽  
Hossein Kazemian ◽  
Sohrab Rohani

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8279
Author(s):  
Silviya Boycheva ◽  
Ivan Marinov ◽  
Denitza Zgureva-Filipova

At present, mitigating carbon emissions from energy production and industrial processes is more relevant than ever to limit climate change. The widespread implementation of carbon capture technologies requires the development of cost-effective and selective adsorbents with high CO2 capture capacity and low thermal recovery. Coal fly ash has been extensively studied as a raw material for the synthesis of low-cost zeolite-like adsorbents for CO2 capture. Laboratory tests for CO2 adsorption onto coal fly ash zeolites (CFAZ) reveal promising results, but detailed computational studies are required to clarify the applicability of these materials as CO2 adsorbents on a pilot and industrial scale. The present study provides results for the validation of a simulation model for the design of adsorption columns for CO2 capture on CFAZ based on the experimental equilibrium and dynamic adsorption on a laboratory scale. The simulations were performed using ProSim DAC dynamic adsorption software to study mass transfer and energy balance in the thermal swing adsorption mode and in the most widely operated adsorption unit configuration.


Catalysts ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1113
Author(s):  
Marco Cocchi ◽  
Doina De Angelis ◽  
Leone Mazzeo ◽  
Piergianni Nardozi ◽  
Vincenzo Piemonte ◽  
...  

The plastic film residue (PFR) of a plastic waste recycling process was selected as pyrolysis feed. Both thermal and catalytic pyrolysis experiments were performed and coal fly ash (CFA) and X zeolites synthesized from CFA (X/CFA) were used as pyrolysis catalysts. The main goal is to study the effect of low-cost catalysts on yields and quality of pyrolysis oils. NaX/CFA, obtained using the fusion/hydrothermal method, underwent ion exchange followed by calcination in order to produce HX/CFA. Firstly, thermogravimetry and differential scanning calorimetry (TG and DSC, respectively) analyses evaluated the effect of catalysts on the PFR degradation temperature and the process energy demand. Subsequently, pyrolysis was carried out in a bench scale reactor adopting the liquid-phase contact mode. HX/CFA and NaX/CFA reduced the degradation temperature of PFR from 753 to 680 and 744 K, respectively, while the degradation energy from 2.27 to 1.47 and 2.07 MJkg−1, respectively. Pyrolysis runs showed that the highest oil yield (44 wt %) was obtained by HX/CFA, while the main products obtained by thermal pyrolysis were wax and tar. Furthermore, up to 70% of HX/CFA oil was composed by gasoline range hydrocarbons. Finally, the produced gases showed a combustion energy up to 8 times higher than the pyrolysis energy needs.


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