Pore structure evaluation of cementing composites blended with coal by-products: Calcined coal gangue and coal fly ash

2018 ◽  
Vol 181 ◽  
pp. 75-90 ◽  
Author(s):  
Jin Yang ◽  
Ying Su ◽  
Xingyang He ◽  
Hongbo Tan ◽  
Youzhi Jiang ◽  
...  
Keyword(s):  
Fly Ash ◽  
Pore Structure ◽  
Coal Fly Ash ◽  
Coal Gangue ◽  
Structure Evaluation ◽  
By Products

Adsorption and stabilization of nickel ions on fly ash/lime mixing

2000 ◽  
Vol 42 (5-6) ◽  
pp. 79-85 ◽  
Author(s):  
P. Ricou-Hoeffer ◽  
V. Héquet ◽  
I. Lécuyer ◽  
P. Le Cloirec
Keyword(s):  
Fly Ash ◽  
Coal Fly Ash ◽  
Influential Factors ◽  
Metallic Ions ◽  
Mass Ratio ◽  
Solution Ph ◽  
Nickel Ions ◽  
Experimental Design Methodology ◽  
By Products ◽  
Lime Addition

Experimental design methodology was used to define conditions for the adsorption and the stabilization of nickel ions (initial concentration of 500 mg.L-1) on coal fly ash/lime sorbent. This type of sorbent allows the reuse of by-products and increases the stabilization of metallic ions by lime addition. It was shown that the solution pH, the metal/adsorbent mass ratio, the type of fly ash used as sorbent, and the fly ash/lime mass ratio are the most influential factors. A set of parameters was finally obtained (pH 5, metal/adsorbent ratio of 0.01 g.g-1, fly ash/lime ratio of 4 g.g-1, fly ash with the lowest content of iron oxide) for which the removal of Ni2+ is 96% and the leaching 0.03% by permuted water and 0.2% by acid solution of pH 2.

scholarly journals Study of Extraction of Rare Earth Elements from Hard Coal Fly Ash

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Ingrid ZNAMENÁČKOVÁ ◽  
Silvia DOLINSKÁ ◽  
Slavomír HREDZÁK ◽  
Vladimír ČABLÍK ◽  
Michal LOVÁS ◽  
...  
Keyword(s):  
Grain Size ◽  
Rare Earth ◽  
Fly Ash ◽  
Rare Earth Elements ◽  
Coal Fly Ash ◽  
Size Reduction ◽  
Hard Coal ◽  
Alternative Possibility ◽  
Laboratory Results ◽  
By Products

Rare earth elements (REEs) extraction from wastes and/or by-products is alternative possibility of their winning. The occurrence ofREEs, namely 50.1 ppm of La, 100.1 ppm of Ce and 44.3 ppm of Nd was confirmed in solid fly ash samples from the coal fired heatingplant (TEKO, Inc. Košice, eastern Slovakia). The submitted contribution presents laboratory results of REEs leaching from coal fly ashusing 3M HCl, HNO3, H2SO4 and H3PO4 at 80°C during 120 min.It was found, that recoveries 65.5% of La, 64.4% Ce and 64.3% of Nd into liquor may be attained after grain size reduction to below5 μm.

Toxicity of coal fly ash and coal gangue leachate to Daphnia magna: Focusing on typical heavy metals

2021 ◽  
pp. 129946
Author(s):  
Weihua Peng ◽  
Yingying Liu ◽  
Manli Lin ◽  
Yan Liu ◽  
Cheng Zhu ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Fly Ash ◽  
Daphnia Magna ◽  
Coal Fly Ash ◽  
Coal Gangue

scholarly journals Processing of high-grade zeolite nanocomposites from solid fuel combustion by-products as critical raw materials substitutes

2020 ◽  
Vol 7 ◽  
pp. 22
Author(s):  
Silviya Boycheva ◽  
Denitza Zgureva ◽  
Hristina Lazarova ◽  
Katerina Lazarova ◽  
Cyril Popov ◽  
...  
Keyword(s):  
Fly Ash ◽  
Power Plants ◽  
Raw Materials ◽  
Coal Fly Ash ◽  
Thermal Power ◽  
Coal Ash ◽  
High Grade ◽  
Fly Ash Zeolite ◽  
By Products ◽  
Critical Raw Materials

High-grade zeolite nanocomposites are synthesized utilizing solid by-products from combustion of coal for energy production in Thermal Power Plants applying alkaline aging, hydrothermal and fusion-hydrothermal activation procedures. The obtained coal ash zeolites were studied with respect to their chemical and phase composition, morphology, surface parameters and thermal properties. It was found that they are distinguished in nanocrystalline morphology and significant content of iron oxide nanoparticles (γ-Fe2O3, α-Fe2O3, γ-Fe3O4) and doping elements (Cu, Co, Mn, V, W, etc.) transferred from the raw coal ash, and therefore they are assumed as nanocomposites. Coal fly ash zeolite nanocomposites are characterized by a mixed micro-mesoporous texture, significant concentration of acidic Brønsted centers due to their high surface insaturation, high chemical and thermal stabilty. This unique combination of compositional and textural properties predetermines the application of these materials as catalysts for thermal oxidation processes, anticorrosion barrier coatings, carbon capture adsorbents, matrices for hosting functional groups, detergents etc. Examples for coal fly ash zeolite applications for substitution of critical raw materials in practice are provided.

Potential Resources from Coal Fly Ash

1984 ◽  
Vol 43 ◽  
Author(s):  
J. S. Watson
Keyword(s):  
Fly Ash ◽  
Iron Oxides ◽  
Coal Combustion ◽  
Coal Fly Ash ◽  
National Laboratory ◽  
Chemical Processes ◽  
Oak Ridge ◽  
Beneficial Uses ◽  
By Products ◽  
Or Applications

AbstractRecent studies at Oak Ridge National Laboratory (ORNL) and elsewhere have identified various chemical processes for recovering useful materials, such as alumina and iron oxides, from coal combustion fly ash. Based on certain assumptions, each of these processes can yield useful products at economical prices. Most processes leave a residual solid waste with a volume only slightly less than that of the original waste. This residue may not present a serious hazard, but its volume alone makes disposal difficult for utilities with limited land available for disposal sites. Characteristics of some of the residues are being studied to determine possible beneficial uses or applications of these by-products.

scholarly journals Hybrid Geopolymers from Fly Ash and Polysiloxanes

Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3510 ◽  
Author(s):  
Giuseppina Roviello ◽  
Laura Ricciotti ◽  
Antonio Jacopo Molino ◽  
Costantino Menna ◽  
Claudio Ferone ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Hybrid Materials ◽  
Power Plants ◽  
Coal Fly Ash ◽  
Synthetic Strategy ◽  
Thermoelectric Power Plants ◽  
First Time ◽  
By Products

The preparation and characterization of innovative organic-inorganic hybrid geopolymers, obtained by valorizing coal fly ash generated from thermoelectric power plants, is reported for the first time. These hybrid materials are prepared by simultaneously reacting fly ash and dimethylsiloxane oligomers at 25 °C in a strongly alkaline environment. Despite their lower density, the obtained materials are characterized by highly improved mechanical properties when compared to the unmodified geopolymer obtained without the use of polysiloxanes, hence confirming the effectiveness of the applied synthetic strategy which specifically aims at obtaining hybrid materials with better mechanical properties in respect to conventional ones. This study is an example of the production of new materials by reusing and valorizing waste raw resources and by-products, thus representing a possible contribution towards the circular economy.

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