Rare earth elements in fly ashes created during the coal burning process in certain coal-fired power plants operating in Poland – Upper Silesian Industrial Region

Environmental contextTrace elements in coastal environments represent an environmental concern and their monitoring in sediment cores provides insight into their historical sources. A well-dated core from Kiel Bay, western Baltic Sea, provided trace element data, including lead, cadmium, rare earth elements, mercury and methyl mercury. Lead and mercury isotope ratios were useful for the apportionment of pollution sources, indicating that coal burning was a major contributor. AbstractWe present a comprehensive study on the variation of trace elements (TEs) and rare earth elements (REEs) in a well-dated sediment core from Kiel Bay, western Baltic Sea. Mass fractions of 34 elements (major and trace) together with other relevant parameters, such as organic carbon and grain size, were determined in a 20-cm core that covers the last century. Enrichment factors and geoaccumulation indices were determined to assess the possible influence of anthropogenic inputs on element distribution. The obtained results show that the highest enrichment of TEs occurred in the period 1917–1970 especially for the priority elements as Hg, Cd and Pb. Determination of methylmercury (MeHg) was also performed, as it showed the highest content in surface samples. The MeHg percentages ranged from 0.02 to 1.2% of the total Hg. REEs, which are nowadays considered as new emerging contaminants, did not reveal high enrichment attributable to anthropogenic influences, but provided useful baseline information for future monitoring of the area. The study of the Pb isotopic composition proved to be a valuable tool in determining the Pb pollution source, and revealed Pb in the layers that showed the highest enrichment came mainly from coal burning. Mercury isotopic signatures in the sediment core were used as a tool to identify the sources of Hg pollution. An isotope mixing model based on mass-dependent (MDF) and mass-independent fractionations (MIF) identified coal burning as the most probable dominant source for Hg anthropogenic contamination in the area.

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Assessment of the potential of polish fly ashes as a source of rare earth elements

Ore Geology Reviews ◽

10.1016/j.oregeorev.2020.103638 ◽

2020 ◽

Vol 124 ◽

pp. 103638

Author(s):

Zdzisław Adamczyk ◽

Joanna Komorek ◽

Barbara Białecka ◽

Jacek Nowak ◽

Agnieszka Klupa

Keyword(s):

Rare Earth ◽

Rare Earth Elements ◽

Fly Ashes

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Distribution of Lanthanides, Yttrium, and Scandium in the Pilot-Scale Beneficiation of Fly Ashes Derived from Eastern Kentucky Coals

Minerals ◽

10.3390/min10020105 ◽

2020 ◽

Vol 10 (2) ◽

pp. 105 ◽

Cited By ~ 6

Author(s):

James C. Hower ◽

John G. Groppo ◽

Prakash Joshi ◽

Dorin V. Preda ◽

David P. Gamliel ◽

...

Keyword(s):

Rare Earth ◽

Fly Ash ◽

Power Plants ◽

Pilot Scale ◽

Fly Ashes ◽

Eastern Kentucky ◽

Minor Elements ◽

High Concentrations ◽

The Individual ◽

Plant Basis

In this study, Central Appalachian coal-derived fly ashes from two power plants were beneficiated in a pilot-scale facility in order to produce a product with a relatively consistent concentration of rare earth elements (REE). The <200-mesh final fly ash product was produced by removing the carbon- and Fe-rich particles prior to screening at 200 mesh (75 µm). The Plant D fly ash had high concentrations of CaO and SO3, which were diminished through the two months when the ash was being beneficiated, representing a consequence of the heat, humidity, and excessive rainfall in the Kentucky summer. The high CaO and SO3 concentrations through the early runs likely contributed to the lower REE in the <200-mesh products of those runs. Of the non-REE minor elements, Ba, V, Mn, Zn, and As showed the greatest between-run variations within the runs for each plant. The overall REE concentrations proved to be similar, both on a between-run basis for the individual fly ash sources and on a between-plant basis. Variations in fly ash quality will occur in larger-scale operations, so on-going attention to the fly ash quality and the response of the fly ash to beneficiation is necessary. Changes in the Plant D fly ash with time imply that both the freshness of the original ash and the length and conditions of its storage at the site of beneficiation could be factors in the quality and consistency of the processed fly ash.

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Distribution of rare earth elements in the pilot-scale processing of fly ashes derived from eastern Kentucky coals: Comparisons of the feed and processed ashes

Fuel ◽

10.1016/j.fuel.2021.120562 ◽

2021 ◽

Vol 295 ◽

pp. 120562

Author(s):

James C. Hower ◽

John G. Groppo ◽

Robert B. Jewell ◽

John D. Wiseman ◽

Tristana Y. Duvallet ◽

...

Keyword(s):

Rare Earth ◽

Rare Earth Elements ◽

Pilot Scale ◽

Fly Ashes ◽

Eastern Kentucky

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Characteristics of Some Selected Methods of Rare Earth Elements Recovery from Coal Fly Ashes

Metals ◽

10.3390/met11010142 ◽

2021 ◽

Vol 11 (1) ◽

pp. 142

Author(s):

Aleksandra Rybak ◽

Aurelia Rybak

Keyword(s):

Rare Earth ◽

Rare Earth Elements ◽

Membrane Separation ◽

Process Efficiency ◽

Fly Ashes ◽

Acid Base ◽

Price Forecast ◽

Advantages And Disadvantages ◽

Wide Range ◽

Coal Fly Ashes

The article covers the issues related to the characteristics, application, and some methods of rare earth elements (REEs) recovery from coal fly ashes. REEs are elements with growing demand and a very wide range of application, especially when it comes to modern technologies. The conducted analysis and price forecast proved the existing upward tendency, and this confirmed the need to search for new REE sources, among industrial waste (proecological effect). The development of the REE recovery technology would involve solving several problems related to REE speciation, optimization of factors controlling their extractivity and selection of the REE separation method from obtained extraction solutions with a very extreme pH and complicated composition. The paper presented advantages and disadvantages of usually used methods of REE separation from coal fly ashes, like physical and acid–base leaching. It was also presented alternative REE recovery techniques in the form of membrane and biological methods and based on ion liquids (ILs) or chelating agents. The directions of further modifications, which will allow the efficient REE recovery were presented. The aim of this article was to propose specific solutions based on the creation of appropriate multistage method of REE recovery. It will be a combination of magnetic and size separation, acid–base leaching (including roasting in justified cases), removal of matrix elements with ILs (Al, Si, and Fe), and finally REE membrane separation, allowing one to obtain the appropriate process efficiency.

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Rare earth elements in deposited hard coal fly ash in Poland

E3S Web of Conferences ◽

10.1051/e3sconf/202127801016 ◽

2021 ◽

Vol 278 ◽

pp. 01016

Author(s):

Justyna Woźniak ◽

Marcel Gurdziel

Keyword(s):

Rare Earth ◽

Fly Ash ◽

Rare Earth Elements ◽

Power Plants ◽

Coal Fly Ash ◽

Raw Material ◽

Hard Coal ◽

Central Statistical ◽

Central Statistical Office ◽

Modern Technologies

Rare Earth Elements (REEs), due to their unique properties, are nowadays a desirable raw material, especially in the development of modern technologies. This paper describes a 4-step research methodology for the task of identifying the potential for REE recovery in landfilled fly ash. A literature analysis was performed on their significance, occurrence in both primary and secondary deposits. Opportunities for REE recovery from coal fly ash in conventional power plants were identified and selected technologies were described. Poland, as a country whose energy sector is to a large extent based on coal, has a potential in this respect. Taking into account studies of the Polish Central Statistical Office (GUS) and forecasts of the Polish energy policy, the article determines the approximate value of REE in the waste stream from coal-fired power plants burning hard coal.

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