Current State of Coal Fly Ash Utilization: Characterization …
1. Introduction and Scope. This Special Issue of Materials is devoted to various aspects of coal fly ash (CFA) utilization. The Guest Editors of the issue were Dr. Alex Kondratiev and Dr. Dmitry Valeev. The Special Issue was designed to include submissions for characterization, mineralogy, hydrometallurgy, recovery of rare earth …
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Coal fly ash application as an eco-friendly approach for
The solid waste known as fly ash, which is produced when coal is burned in thermal power plants, is sustainably used in agriculture. It is an excellent soil supplement for plant growth and development since it contains some desired nutrients (macro and micro), as well as being porous. The present study was done to evaluate the effect of different …
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Science breaks new ground in converting coal ash from pollutant …
Fly ash can be used to neutralise and treat acid mine drainage from coal or gold mines, reducing major inorganic contaminants in the water to within water quality specifications.
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Flash Joule heating extracts rare earth elements from fly ash, …
00:00. Rice University scientists applied their flash Joule heating process to coal fly ash and other toxic waste to safely extract rare earth elements essential to modern electronics and green ...
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A clay-coal fly ash based dual hydraulic-reactive liner for …
Hydraulic liners are used to restrict hazardous leachates such as acid mine drainage (AMD) from entering the hydrogeological system. In this study, we hypothesized that: (1) a compacted mix ratio of natural clay and coal fly ash with a hydraulic conductivity of at most 1 × 10− 8 ms− 1 can be achieved, and (2) mixing clay and coal fly ash in the …
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FS 2019-3048: Rare Earth Elements in Coal and Coal Fly …
Country totals may not add exactly to the world total because of rounding. U.S. Department of the Interior U.S. Geological Survey Fact Sheet 2019–3048 September 2019. Table 1. Rare-earth-element (REE) contents of fly ash samples investigated, basins where coals yielding the ash originated, and percentages of critical REEs of the total REE ...
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Mining precious rare-earth elements from coal fly ash …
The researchers pretreated coal fly with an alkaline solution and dried it. Then, they heated ash suspended in water with [Hbet] [Tf 2 N], creating a single phase. When cooled, the solutions ...
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Flash Joule heating extracts rare earth elements from …
Microscopic glass spheres found in coal fly ash contain rare earth elements that could be recycled rather than buried in landfills, according to Rice University scientists. Their flash Joule...
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Thermo-mechanical properties and microfabric of fly ash-stabilized gold
Fig. 1 shows the particle size distributions of the gold tailings and coal fly ash. Both materials are well graded and primarily silt-sized particles, non-plastic, classified as ML according to the Unified Soil Classification System (USCS). The specific gravity of the tailings is 3.28, which is greater than that of most soils due to predominant ...
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Synthesis and characterization of pure phase zeolite 4A from coal fly ash
The obtained results revealed that the fly ash was comprised of 67% aluminosilicate content that would supply a readily available source of zeolite synthesis as Si and Al precursors (Ameh et al., 2017).The SiO 2 /Al 2 O 3 ratio was found to be 2.03 and that was a good indication for zeolitization of fly ash since this ratio is suitable for the …
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Preparation of porous glass-ceramics from coal fly ash …
Considering that coal fly ash and asbestos tailings contain a large amount of SiO 2, Al 2 O 3, MgO and CaO, ... The microstructure and elemental analysis of the porous glass-ceramics sprayed with gold were analyzed by a scanning electron microscope (SEM/EDS, Ultra55). The pore size distribution of ed glass-ceramics were obtained …
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FS 2019-3048: Rare Earth Elements in Coal and Coal Fly …
Fly ash, produced during the burn ing of coal, is a fine grained solid derived from noncombustible constituents of coal, such as clay minerals and quartz. When coal is burned, REEs are retained and enriched in the fly ash and, as a result, fly ash has long been considered a potential resource for REEs (Goldschmidt, 1935; Seredin and Dai, …
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Coal fly ash: an emerging material for water remediation
Coal fly ash (CFA) is a byproduct of thermal power plant and collected from flue gases by separator. Composition of CFA depends on the type of coal used and it has both crystalline and amorphous character. It is considered to be an environmental pollutant and used in number of areas. CFA is a useful material and widely used in cement production and as …
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Extraction of heavy metals from MSWI fly ash using
With this work, a detailed laboratory study on different filter cakes from fly ash leaching using HCl 5% (represents the FLUWA process) and concentrated sodium chloride solution (300 g/L) is described. This two-step leaching of fly ash is an efficient combination for the mobilization of a high percentage of heavy metals from fly ash (Pb, Cd ≥ ...
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Advancements of coal fly ash and its prospective …
The concern with using coal lies in producing by-products from burning coal. Various studies have shown that the disposal of by-products has become a burden to the environment because it disrupts environmental and economic cycles [13].CFA is generally a mixture of minerals consisting of various oxides, including SiO 2 (35–60 %), CaO (1–35 …
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Determination of total mercury in coal fly ash by gold …
A method for the determination of total mercury in coal fly ash by gold amalgamation cold vapour atomic absorption spectrometry (CV-AAS) was optimized. Most of the experiments were performed on NBS SRM 1633a Coal Fly Ash with a certified value of 160 ± 10 ng Hg g −1. The main attention was focused on the decomposition of …
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The occurrence of gold in fly ash derived from high …
We present the first data on the mode of occurrence of Au in fly ashes from the Wulantuga and Lincang power plants in China, which burn high-Ge coal. Gold …
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The occurrence of gold in fly ash derived from high-Ge coal
Abstract. We present the first data on the mode of occurrence of Au in fly ashes from the Wulantuga and Lincang power plants in China, which burn high-Ge coal. Gold occurs as fine-grained drop-like particles with a size of n *0.01–0.2 μm on the surface of the glass globules. These features of the Au particles are proof for Au condensation ...
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Synthesis and characterization of coal fly ash and palm oil fuel ash …
The average unconfined compressive strengths (UCS) of tailings-based geopolymers at 14 days curing were 7.58 MPa and 7.7 MPa with fly ash and palm oil fuel ash, respectively.
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Analysis of Coal Fly Ash
The most common fly ash is coal fly ash produced at coal-fired power, yet incineration of other materials such as biomass and refused-derived fuels (RDF) also produces fly ash. Fly ash has valuable use in many building products such as Portland cement and concrete, as well as being used for soil stabilization, fertilization, and other ...
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Distribution of Rare Earth Elements in Coal and Coal Fly Ash
Coal fly ash (CFA) is one such resource having 300–500 mg/kg of REEs globally. It is very essential to figure out the distribution of REEs, in coal fly ash in order to develop effective methods to recover REEs. ... Except promethium, all REEs are more plentiful than precious metals like platinum, gold, and silver. On the basis of abundance …
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Heavy metal removal from coal fly ash for low carbon …
Coal fly ash (CFA) is an attractive cement diluent additive but contains heavy metals which could slowly leach out. Deng, Meng and colleagues report a rapid and water-free process to remove the ...
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Coal Fly Ash
Abstract. By-products (fly ash) obtained from the combustion process of boiler fuels (coal) is a valuable asset to the construction industry. In order to control the pollution, industries are adopting cofiring of coal with bio-fuels. These cofired ashes alter in physical and chemical properties with reference to (a by-product of burnt coal) fly ...
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A comprehensive review on the applications of coal fly ash
Coal fly ash is one of the most complex of the materials that can be characterized. Approximately 316 individual minerals and 188 mineral groups have been identified in various ash samples (Vassilev and Vassileva, 1997, Vassilev et al., 2003, Vassilev and Vassileva, 2005).The major components are metallic oxides with varying …
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The effect of sintering temperature on cavitation erosion in …
The incombustible portion of coal that remains after burning is known as bottom or fly ash, and it has a detrimental influence on the environment. One of the possible alternatives for reducing the amount of ash deposited in landfills might be the production of useful glass–ceramic from vitrified fly ash. Glass–ceramic was synthesized …
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Fate of the naturally occurring radioactive materials
Treatment of mine water with coal fly ash. Gold mine water (80 L) and coal FA (13 kg) were mixed together using a jet loop reactor with jet nozzle sizes set at 8 mm. After 30 min, 86.58 g of Al(OH) 3 was added to the mixture. The pH, EC and temperature were measured after 15 min and aliquot samples were collected after every 30 min for …
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Coal Ash
Coal ash is the waste produced when coal is burned for electricity. It consists of both fly ash, which is captured by "scrubbers" in the smokestacks to prevent air pollution, and bottom ash, which settles to the bottom of the furnaces. Coal ash contains 25 heavy metals, including arsenic, mercury, lead, selenium and chromium, as well as ...
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The occurrence of gold in fly ash derived from high …
Shifeng Dai. China University of Mining and Technology-Beijing. Abstract and Figures. We present the first data on the mode of occurrence of Au in fly ashes from the Wulantuga and Lincang power...
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Mechanism of bioleaching of coal fly ash by
Bioleaching of aluminum and iron from coal fly ash (CFA) by Thiobacillus thiooxidans ( T. thiooxidans) bacteria is considered. The interactions between bacteria, metabolic products, CFA particles, and leaching products were studied. It is demonstrated that bacterial growth and the amount of metals leached from the CFA are coupled …
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Valorization of coal fly ash (CFA): a multi-industry review
Coal fly ash (CFA) management has become a global environmental concern due to their impact on the environment and the quantities of the waste generated. However, the utilization of CFA as feedstock in industrial processes is considered a promising option for managing the waste sustainably. The physical, chemical and …
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