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 Preparation of Synthetic Zeolites from Coal Fly Ash by Hydrothermal Synthesis

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1267
Author(s):  
David Längauer ◽  
Vladimír Čablík ◽  
Slavomír Hredzák ◽  
Anton Zubrik ◽  
Marek Matik ◽  
...  
Keyword(s):  
Fly Ash ◽  
Coal Combustion ◽  
Power Plants ◽  
Coal Fly Ash ◽  
Thermal Power ◽  
Product Analysis ◽  
Coal Combustion Products ◽  
X Ray ◽  
Wide Range ◽  
Silica Alumina

Large amounts of coal combustion products (as solid products of thermal power plants) with different chemical and physical properties cause serious environmental problems. Even though coal fly ash is a coal combustion product, it has a wide range of applications (e.g., in construction, metallurgy, chemical production, reclamation etc.). One of its potential uses is in zeolitization to obtain a higher added value of the product. The aim of this paper is to produce a material with sufficient textural properties used, for example, for environmental purposes (an adsorbent) and/or storage material. In practice, the coal fly ash (No. 1 and No. 2) from Czech power plants was firstly characterized in detail (X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDX), particle size measurement, and textural analysis), and then it was hydrothermally treated to synthetize zeolites. Different concentrations of NaOH, LiCl, Al2O3, and aqueous glass; different temperature effects (90–120 °C); and different process lengths (6–48 h) were studied. Furthermore, most of the experiments were supplemented with a crystallization phase that was run for 16 h at 50 °C. After qualitative product analysis (SEM-EDX, XRD, and textural analytics), quantitative XRD evaluation with an internal standard was used for zeolitization process evaluation. Sodalite (SOD), phillipsite (PHI), chabazite (CHA), faujasite-Na (FAU-Na), and faujasite-Ca (FAU-Ca) were obtained as the zeolite phases. The content of these zeolite phases ranged from 2.09 to 43.79%. The best conditions for the zeolite phase formation were as follows: 4 M NaOH, 4 mL 10% LiCl, liquid/solid ratio of 30:1, silica/alumina ratio change from 2:1 to 1:1, temperature of 120 °C, process time of 24 h, and a crystallization phase for 16 h at 50 °C.

The Latest Research in Mongolia on the Utilization of Coal Combustion By-Products

2021 ◽  
Vol 323 ◽  
pp. 8-13
Author(s):  
Jadambaa Temuujin ◽  
Damdinsuren Munkhtuvshin ◽  
Claus H. Ruescher
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Coal Combustion ◽  
Power Plants ◽  
Thermal Power ◽  
Thermal Power Plants ◽  
Power Stations ◽  
Thermal Power Stations ◽  
Coal Ashes ◽  
By Products

With a geological reserve of over 170 billion tons, coal is the most abundant energy source in Mongolia with six operating thermal power stations. Moreover, in Ulaanbaatar city over 210000 families live in the Ger district and use over 800000 tons of coal as a fuel. The three thermal power plants in Ulaanbaatar burn about 5 million tons of coal, resulting in more than 500000 tons of coal combustion by-products per year. Globally, the ashes produced by thermal power plants, boilers, and single ovens pose serious environmental problems. The utilization of various types of waste is one of the factors determining the sustainability of cities. Therefore, the processing of wastes for re-use or disposal is a critical topic in waste management and materials research. According to research, the Mongolian capital city's air and soil quality has reached a disastrous level. The main reasons for air pollution in Ulaanbaatar are reported as being coal-fired stoves of the Ger residential district, thermal power stations, small and medium-sized low-pressure furnaces, and motor vehicles. Previously, coal ashes have been used to prepare advanced materials such as glass-ceramics with the hardness of 6.35 GPa, geopolymer concrete with compressive strength of over 30 MPa and zeolite A with a Cr (III) removal capacity of 35.8 mg/g. Here we discuss our latest results on the utilization of fly ash for preparation of a cement stabilized base layer for paved roads, mechanically activated fly ash for use in concrete production, and coal ash from the Ger district for preparation of an adsorbent. An addition of 20% fly ash to 5-8% cement made from a mixture of road base gave a compressive strength of ~ 4MPa, which exceeds the standard. Using coal ashes from Ger district prepared a new type of adsorbent material capable of removing various organic pollutants from tannery water was developed. This ash also showed weak leaching characteristics in water and acidic environment, which opens up an excellent opportunity to utilize.

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

scholarly journals Analysis of Content of Selected Critical Elements in Fly Ash

2016 ◽  
Vol 62 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Dorota Makowska ◽  
Faustyna Wierońska
Keyword(s):  
Fly Ash ◽  
Coal Combustion ◽  
Power Plants ◽  
Raw Materials ◽  
Coal Fly Ash ◽  
New Mineral ◽  
The European Union ◽  
Cobalt Chromium ◽  
Critical Elements ◽  
Potential Source

AbstractPursuant to the new mineral policy of the European Union, searching for new sources of raw materials is required. Coal fly ash has long been considered as a potential source of a number of critical elements. Therefore, it is important to monitor the contents of the critical elements in fly ash from coal combustion. The paper presents the results of examinations of the contents of selected elements, i.e. beryllium, cobalt, chromium and germanium in fly ash from Polish power plants. The results of the conducted investigations indicate that the examined ash samples from bituminous coal combustion cannot be treated as a potential source of the analysed critical elements. The content of these elements in ash, though slightly higher than their average content in the sedimentary rocks, is, however, not high enough to make their recovery technologically and economically justified at this moment.

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.

scholarly journals Mineralogy and chemical composition of technogenic soils (Technosols) developed from fly ash and bottom ash from selected thermal power stations in Poland

2015 ◽  
Vol 66 (2) ◽  
pp. 82-91 ◽  
Author(s):  
Łukasz Uzarowicz ◽  
Zbigniew Zagórski
Keyword(s):  
Fly Ash ◽  
Chemical Composition ◽  
Iron Oxides ◽  
Mineral Composition ◽  
Coal Combustion ◽  
Bituminous Coal ◽  
Bottom Ash ◽  
Major Elements ◽  
Soil Horizons ◽  
Technogenic Soils

Abstract The aim of the study was to determine the mineral and chemical composition of technogenic soils (Technosols) developed from fly ash and bottom ash from power plants in which bituminous coal and lignite was combusted. The mineral composition of the “fresh” wastes (i.e. fly ash and bottom ash) and soil samples derived from them was examined by X-ray diffraction (XRD) and using a scanning electron microscope (SEM). The chemical composition (content of major elements) was determined using ICP-AES method. Quartz, mullite, and amorphous substances (glass) predominated in the mineral composition of wastes after bituminous coal combustion. Magnetite was also found there. Soils developed from wastes after bituminous coal combustion contained all above mentioned minerals inherited from fly ash and bottom ash. Moreover, small amounts of secondary calcite were identified. In some soil horizons containing large amounts of inherited magnetite, secondary iron oxides and oxyhydroxides (goethite and lepidocrocite) also occurred. Quartz predominated in the mineral composition of the “fresh” wastes after lignite combustion. Relatively small amounts of iron oxides (magnetite and hematite) were also found there. In “fresh” fly ash, apart from minerals mentioned above, anhydrite and calcium oxide (lime) was identified. Soils developed from wastes after lignite combustion contained inherited quartz, magnetite, and hematite. Furthermore, calcite which sometimes was a predominating mineral in certain soil horizons occurred. Moreover, sulphates (gypsum, bassanite, and ettringite), and vaterite (a polymorph of Ca carbonate) were also found in soils. Silicon predominated among major elements in “fresh” ashes after bituminous coal combustion and soil derived from them followed by Al, Fe, K, Ca, Mg, Ti, Na, P, and Mn. On the other hand, the contents of major elements in the samples (ashes and soils) after lignite combustion can be arranged as follows: Si, Ca, Fe, Al, Mg, Ti, K, Mn, Na, and P. However, in some horizons (i.e. in calcareous materials deposited in the topsoil of some profiles) in soil developed on landfills near TPSs combusting lignite, Ca was a predominating element.

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