Heavy metals and coal
Coal Ash. Burning coal produces airborne compounds, known as fly ash and bottom ash (collectively referred to as coal ash), which can contain large quantities of heavy metals that settle or wash out of the atmosphere into oceans, streams, and land. The amount of fly ash is going up: in 2006, coal plants in the United States produced almost 72 million tons, up …
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Energies | Free Full-Text | Migration and Transformation of Vanadium …
The volatilization characteristics and occurrence forms of V and Ni in petroleum coke (petcoke) were investigated during steam (H2O) and carbon dioxide (CO2) gasification on a fixed bed reactor at 800–1100 °C. The Tessier sequential chemical extraction procedure was employed to determine the different forms of V and Ni. The …
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Materials | Free Full-Text | Current State of Coal Fly Ash …
The degree of extraction of vanadium into the solution during sulfuric acid leaching of ash was 18.9%. In slag, this figure increased to 72.3–96.2%. In the ash sample, vanadium was found in the form of V 5+, V 4+ compounds, vanadium oxides VO 2 (V 4+), V 2 O 5 (V 5+), and V 6 O 13, and nickel orthovanadate Ni 3 (VO 4) 2 (V 5+) was found in it.
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Recovery of metals and other beneficial products from coal fly ash…
Increasing production and disposal of coal fly ash (CFA) is a matter of serious environment concern. However, CFA contains various beneficial metals and mineral matters whose demand is increasing in the industrialized world, while natural supplies are diminishing. Therefore, recovery of these potential resources from CFA can be an …
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(PDF) Vanadium – Valuable and toxic element in coal combustion ash…
PDF | On Feb 1, 2023, Lucie Bartoňová and others published Vanadium – Valuable and toxic element in coal combustion ash: An overview | Find, read and cite all the research you need on ResearchGate
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Effect of Vanadium on the Petroleum Coke Ash Fusibility
The ash fusion temperature (AFT) profile of a coal is one of the parameters currently widely used in coal marketing and utilization to assess coal ash fusibility and melting characteristics, and ...
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Effect of vanadium and nickel on iron-rich ash fusion …
Ash chemistries were chosen such that they correspond to coal−petcoke feedstock mixtures with coal ash amounts of 0, 10, 30, 50, 70, and (by weight), with the balance being petcoke ash.
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Vanadium – valuable and toxic element in coal combustion …
Vanadium – valuable and toxic element in coal combustion ash: an overview. L. Bartoňová, H. Raclavská, J. Najser. Published in Chemical engineering …
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Recovery of vanadium and nickel from heavy oil fly ash …
The main organic acid produced by this fungus is malic acid. The optimum parameters for bioleaching of V and Ni from HOFA are; the fly ash concentration is 1% (w/v), pH is 6 for V and pH is 8 for Ni, and the bioleaching time is 10 days. The maximum recovery obtained for V and Ni is 65.4% and 74.6%, respectively.
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Recovery of gallium from coal fly ash
Abstract. A study has been made on the extraction of gallium from coal fly ash. A process which includes acid leaching, impurity removal, extraction of gallium and its purification has been suggested. The relatively moderate conditions of temperature, acid strength and time should be chosen in acid leaching to obtain the most efficient ...
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Spent-medium leaching of germanium, vanadium and lithium from coal …
@article{Rezaei2023SpentmediumLO, title={Spent-medium leaching of germanium, vanadium and lithium from coal fly ash with biogenic carboxylic acids and comparison with chemical leaching}, author={Homa Rezaei and Sied Ziaedin Shafaei and Hadi Abdollahi and Sina Ghassa and Zohreh Boroumand and Ali Reza Fallah Nosratabad}, …
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COAL ASH IN ALASKA
The 40‐acre the Emory and gallons coal after coal is burned.1 About 141 million tons of coal ash are produced annually thick, toxic river sludge. ofvalley, plants were pproximately generated in the United 79,651 in‐state States.2 After the spill, water samples showed by coal‐fired metric in 2009.
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Transformation and Distribution of Vanadium Phases in Stone Coal …
Stone coal is a kind of carbonaceous shale that contains vanadium. In China, the reserves of vanadium in stone coal are 1.18×l0 5 t in terms of V 2 O 5, accounting for more than 87% of the Chinese reserve of vanadium [1,2,3,4,5].The mineral compositions of stone coal are very complex, and the occurrence state and valency of …
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Effect of vanadium and nickel on iron-rich ash fusion characteristics
The ash fusibility of coal blended with petroleum coke is significantly influenced by vanadium and nickel from petroleum coke. The effects of vanadium (V) and nickel (Ni) on iron-rich ash, such as coal ash with ferrum-based flux addition, are lack of study. This study investigates the effect of vanadium pentoxide (V 2 O 5 ), nickel …
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Chemical Speciation of Vanadium in Coal Bottom Ash
The most abundant form of vanadium in coal bottom ash is residual fraction of vanadium (196 mg kg −1 d.w.). Relative abundances of the remaining vanadium fractions in coal bottom ash are as follows: Reducible (176 mg kg −1 d.w.) > …
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Extracting vanadium from stone-coal by oxygen pressure …
Vanadium recovery from oil fly ash by leaching, precipitation and solvent extraction processes [J] ... D2EHPA molecules also dimerized to form a cyclic chelate complex with vanadium, which contributed to the solvent extraction of vanadium. Lastly, the solution chemical behavior of the vanadium in the organic phase after extraction with …
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Transformation and Distribution of Vanadium Phases in Stone Coal …
Stone coal pellets were roasted in a bench scale fluidized bed combustor, and V2O5 was extracted by acid leaching from ash and slug. Main factors influencing pellet-remaining ratio and vanadium ...
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Preparation of SiC from carbonaceous vanadium-bearing stone coal …
In this study, carbonaceous vanadium-bearing stone coal obtained from Henan province, China was utilized as the primary raw material. Analytically pure V 2 O 3 was added as an additive to examine the catalytic effect of vanadium during the preparation of SiC. The chemical composition analysis of the raw material was carried out using X-ray …
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A sustainable method for germanium, vanadium and lithium …
Abstract. The paper proposes an environmentally friendly process for recovering germanium, lithium, and vanadium from coal fly ash (CFA) using thermal …
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Transformation and Distribution of Vanadium Phases in …
vanadium in fly ash was easier than that in stone coal. Keywords Stone coal ·Combustion fly ash ·Vanadium phases ·Sequential chemical extraction Introduction Stone coal is a kind of carbonaceous shale that contains vanadium. In China, the reserves of vanadium in stone coal are 1.18×l05 t in terms of V 2O 5, accounting for
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Chemical Speciation of Vanadium in Coal Bottom Ash
Total vanadium concentration in the coal bottom ash is 701 mg kg −1 d.w. The most abundant form of vanadium in coal bottom ash is residual fraction of …
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(PDF) COAL ASHES AS A VANADIUM RESOURCE …
Vanadium content is quite high in coal as high as % 0,5 V, and over 1% V in ashes. ... uranium-vanadium minerals form t he matrix of the mineralized sandstones and locally replace .
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Vanadium – Valuable and toxic element in coal combustion …
Vanadium. Coal combustion. Ash. Physical separation. Leaching. Wastes. 1. Introduction. Annual production of V is estimated to be around 100.000 t ( Bielowicz, 2020, Chinach, 2020 ); the largest producers are China, South Africa and Russia ( Bielowicz, …
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Vanadium recovery as FeV from petroleum fly ash
According to the XRD analysi s, vanadium in the petroleum-fly ash occurs mainly in the form of VOSO 4 ·3H 2 O, and the existing fo rm of nickel is identified as NiS 2 O 6 .6H 2 O. There are ...
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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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Bioleaching performance of vanadium-bearing smelting ash …
The XRD results showed that vanadium mainly existed in the form of vanadium oxides (i.e., VO 2, V 2 O 3) (Fig. 1). The smelting ash also contained other metals (e.g., iron, manganese, aluminum), which were transferred into the leaching liquor during the leaching/bioleaching process. After the acid leaching with acetate buffer, the …
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Vanadium recovery from oil fly ash by leaching, …
Precipitation was performed in a two-step procedure: (a) aluminum was first precipitated at pH 8; (b) then ammonium chloride was added at pH 5 to bring about vanadium precipitation. In order to reduce the environmental impact due to land disposal of oil fly ash from power plants and to valorize this waste material, the removal of vanadium was ...
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Ash Characteristics and Selected Critical Elements (Ga, …
The analysis of the chemical composition of ash and the share of elements in coal and ash was conducted in an accredited laboratory (the Bureau Veritas Minerals Laboratory). ICP-MS analysis used a sample after modified aqua regia digestion (1:1:1 HNO3/HCl/H2O) for low to ultra-low determination of both coal and ash.
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A literature review on leaching and recovery of vanadium
Zhang [28] leached out vanadium from stone coal with 6 wt.% NaCl and 10 wt.% Na 2 SO 4 as roasting additive. During the roasting process, the vanadium-bearing muscovite with quartz was converted to feldspar group minerals (albite, orthoclase and anorthite). The findings could produce some potential methods for recovery of vanadium …
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Viscosity of coal ash slag containing vanadium and nickel
Wang et al. 12 found that V in coal ash slag forms a V−O−Al bond with Al 2 O 3 . In addition, the X-ray diffraction analyses of Li et al. 33 identified the existence of V 2 O 3 and FeV 2 O 4 ...
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