scholarly journals Ash Characteristics and Selected Critical Elements (Ga, Sc, V) in Coal and Ash in Polish Deposits

Resources ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 115
Author(s):  
Barbara Bielowicz
Keyword(s):  
Chemical Composition ◽  
Bituminous Coal ◽  
Raw Materials ◽  
Coal Ash ◽  
Proximate Analysis ◽  
Petrographic Composition ◽  
Critical Elements ◽  
Icp Ms ◽  
Coal Ashes ◽  
The Relationship

The chemical composition of coal ash and the content of the critical elements Ga, Sc, and V in coal and ash are examined herein. In this study, lignite and bituminous coal from Polish deposits were used. The coals were subjected to ultimate and proximate analysis; the petrographic composition was determined based on maceral groups. The chemical composition of ash and the content of critical elements were determined using ICP-MS. The obtained results were correlated and Pearson’s linear correlation coefficient was determined. Based on the correlation analysis, the relationship between the chemical composition of ash and the proximate and ultimate analyses was demonstrated. The content of selected critical elements in the tested deposits was lower than the Clarke value in coal. However, in some deposits these contents are much higher in coal ashes. The higher levels of Ga, V, and Sc in the ash are associated with Al2O3. Therefore, it can be stated that ashes can be a potential source of some raw materials. The highest concentrations of critical elements in coal and ash were recorded in the Lublin Coal Basin. Supra-Clarke contents of Ga, V, and Sc were recorded in the Bogdanka coal mine.

scholarly journals Selected Critical Raw Materials in Waste from Coal Gasification in Poland

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8071
Author(s):  
Barbara Bielowicz
Keyword(s):  
Coal Gasification ◽  
Raw Materials ◽  
Coal Ash ◽  
Earth’S Crust ◽  
Critical Elements ◽  
Grade Levels ◽  
Upper Silesian Coal Basin ◽  
Icp Ms ◽  
Earth's Crust ◽  
Critical Raw Materials

In an effort to identify new sources of critical raw materials (CRMs) possibility of recovering selected CRMs from Polish coals, chars, and ashes resulting from the combustion of coals and chars was investigated. The samples were collected from pilot fluidized bed gasification systems. The search for CRMs in coal gasification wastes has not been widely reported before. The study used 2 bituminous coal and 1 lignite sample; the concentration of individual critical raw materials (CRMs) was analyzed using the ICP-MS method. The obtained results were compared with Clarke values in coal ash and in the Earth’s crust, and with the adopted cut-off grade. As shown by the analysis, the highest concentrations of CRMs can be found in fly ash, mainly in samples from the eastern part of the Upper Silesian Coal Basin. This applies mostly to Be, Cs, or Sb due to the fact that their concentrations were found to be higher than the Clarke value in the Earth’s crust; the mentioned fly ashes could be used as potential sources of critical elements if appropriate recovery technologies are developed. In addition, the tested materials have elevated Se, Pb, Ni concentrations, but their recovery is currently not economically viable. Compared to the currently adopted cut-off grade levels, there are no critical elements in the analyzed coal gasification waste that could be recovered.

scholarly journals Morphology and chemical composition of mineral matter present in fly ashes of bituminous coal and lignite

2020 ◽  
Author(s):  
E. Strzałkowska
Keyword(s):  
Chemical Composition ◽  
Bituminous Coal ◽  
Coal Ash ◽  
Heterogeneous Material ◽  
Raw Material ◽  
Spherical Particles ◽  
Hard Coal ◽  
Mineral Matter ◽  
Fly Ashes ◽  
Main Component

AbstractThe changing properties of energy waste force us to look for alternative directions of their use. The aim of the research presented in this paper was to indicate the possibilities of managing fly ashes from bituminous coal and lignite based on the observation of individual particles of these ashes. Innovative research techniques were used, among others: SEM with EDS detector and Image Analysis. Microscopic observations have shown that fly ashes are a heterogeneous material composed of particles occurring in three basic morphological forms: spherical, irregular and fine-detritic. A high proportion of spherical particles was found in bituminous coal ashes (rich in SiO2 and Al2O3), which gives them high pozzolanic activity. This kind of morphology and chemical composition make these ashes a potential material for zeolites synthesis. The amorphic phase of ash from lignite coal has aluminium–silicate-calcium chemical composition, which is what determines pozzolanic and hydraulic properties of these ashes. Magnetic separation of iron-rich particles may be a way to manage the researched ashes. One of the valuable components of hard coal ash are microspheres, which are characterized by high variability in chemical composition, so further utilization will require prior refining. The main component of irregular particles found in ashes is unburned coal and, to a lesser extent, a mineral substance. The separation of all useful components from the tested ashes before their further management will allow the full use of their raw material potential.

Corrosion of MgAl2O4 Spinel with Different Al2O3 Contents in Iron-Containing Gasifier Slag

2018 ◽  
Vol 281 ◽  
pp. 118-124 ◽  
Author(s):  
Hong Gang Sun ◽  
Hong Xia Li ◽  
Wen Bin Jiao
Keyword(s):  
Solid Solution ◽  
Chemical Composition ◽  
Melting Point ◽  
Raw Materials ◽  
Absorption Capacity ◽  
Reducing Atmosphere ◽  
Before And After ◽  
The Relationship ◽  
Slag Corrosion ◽  
Spinel Ceramic

The MgAl2O4 spinel ceramic specimens with five different alumina contents ( w(Al2O3)=66%,72%,78%,85%,90%) were prepared using alumina micropowder and magnesia micropowder as raw materials, after mixing, shaping, drying, and heating at 1800 °C. The crucible specimens were tested for slag corrosion with commercial gasifier slag at 1500 °C for 2 h under oxidazing and reducing atmosphere. The specimens before and after slag test were studied by analyzing the microstructure and element distributions of corroded specimens with XRD, SEM and EDS. The results show that the slow dissolution of spinel into slag was observed because a low melting point material was formed by spinel reacting with CaO and SiO2 in slag on the surface of the spinel block. Meanwhile, FeOx in the slag was absorbed around the surface of spinel block to form the multiple solid solution, which was composed of MgO-Al2O3-FeOx and had a denser microstructure. The absorption of FeOx in slag had contributed to the resistance to slag penetration for the spinel. The relationship between the absorption capacity of spinel on FeOx and the chemical composition of spinel was discussed.

scholarly journals Copper slag as a potential source of critical elements - A case study from Tsumeb, Namibia

2021 ◽  
Vol 121 (3) ◽  
Author(s):  
S. Lohmeier ◽  
B.G. Lottermoser ◽  
T. Schirmer ◽  
D. Gallhofer
Keyword(s):  
Chemical Composition ◽  
Value Chain ◽  
Inductively Coupled Plasma ◽  
Copper Slag ◽  
Critical Element ◽  
Metals And Metalloids ◽  
X Ray ◽  
Critical Elements ◽  
Dissipative Loss ◽  
Icp Ms

SYNOPSIS At a time of resource consumption, it is important to study the chemical composition of mining and metallurgical wastes to prevent the dissipative loss of metals and metalloids from the mining value chain. In particular, the recovery of critical elements from wastes is an option to increase the resources of such materials that are economically significant and have an overall supply risk. In this paper we report on the chemical composition, in particular the critical element content, of granulated slag originating from historical smelting activities in the Tsumeb area, Namibia. Laboratory-based inductively coupled plasma-mass spectrometry (ICP-MS) and X-ray fluorescence (XRF) analyses as well as portable X-ray fluorescence (pXRF) demonstrate that the slags are on average enriched in base metals (Cu 0.7 wt%, Pb 2.7 wt%, Zn 4.7 wt%), trace metals and metalloids (Cd approx. 50 mg/kg, Mo approx. 910 mg/kg) as well as critical elements (As approx. 6300 mg/kg, Bi approx. 3 mg/kg, Co approx. 200 mg/kg, Ga approx. 100 mg/kg, In approx. 9 mg/kg, Sb approx. 470 mg/kg). While metals and metalloids such as As, Mo and Pb can be determined reliably using pXRF instruments, the technique has inherent limitations in evaluating the contents of certain critical elements (Ga, Sb). However, there are positive correlations between the As, Mo, and Pb contents determined by pXRF and the Ga and Sb contents obtained through ICP-MS and XRF. Thus, quantitative pXRF analysis for As, Mo, and Pb allows calculation of Ga and Sb abundances in the slags. This work demonstrates that pXRF analysers are a valuable tool to screen smelting slags for their chemical composition and to predict the likely contents of critical elements. Keywords: base metal slag, portable XRF, critical elements, secondary resource.

scholarly journals Critical Elements in Fly Ash from the Combustion of Bituminous Coal in Major Polish Power Plants

2018 ◽  
Vol 35 ◽  
pp. 02003 ◽  
Author(s):  
Barbara Bielowicz ◽  
Dariusz Botor ◽  
Jacek Misiak ◽  
Marian Wagner
Keyword(s):  
Fly Ash ◽  
Enrichment Factor ◽  
Power Plants ◽  
Bituminous Coal ◽  
Thermal Power ◽  
Sedimentary Rocks ◽  
Coal Ash ◽  
Average Concentration ◽  
Global Average ◽  
Critical Elements

The concentration of critical elements, including such REE as Fe, Co, W, Zn, Cr, Ni, V, Mn, Ti, Ag, Ga, Ta, Sr, Li, and Cu, in the so-called fly ash obtained from the 9 Polish power plants and 1 thermal power station has been determined. The obtained values, compared with the global average concentration in bituminous coal ash and sedimentary rocks (Clarke values), have shown that the enrichment of fly ash in the specified elements takes place in only a few bituminous coal processing sites in Poland. The enrichment factor (EF) is only slightly higher (the same order of magnitude) than the Clarke values. The enrichment factor in relation to the Clarke value in the Earth’s crust reached values above 10 in all of the examined ashes for the following elements: Cr, Ni, V, W, and, in some ash samples, also Cu and Zn. The obtained values are low, only slightly higher than the global average concentrations in sedimentary rocks and bituminous coal ashes. The ferromagnetic grains (microspheres) found in bituminous coal fly ashes seem to be the most economically prospective in recovery of selected critical elements. The microanalysis has shown that iron cenospheres and plerospheres in fly ash contain, in addition to enamel and iron oxides (magnetite and hematite), iron spinels enriched in Co, Cr, Cu, Mn, Ni, W, and Zn.

Spectral Thermal Radiation Characteristics of Coal Ashes and Slags: Influence of Chemical Composition and Temperature

2003 ◽  
Author(s):  
S. Linka ◽  
S. Wirtz ◽  
V. Scherer
Keyword(s):  
Heat Transfer ◽  
Chemical Composition ◽  
Thermal Radiation ◽  
Coal Ash ◽  
Spectral Emissivity ◽  
Department Of Energy ◽  
Radiation Characteristics ◽  
Transfer Rates ◽  
Inorganic Species ◽  
Coal Ashes

During the combustion of pulverized coal, ash particles (formed from inorganic species) can deposit on heat-transfer surfaces, resulting in a decrease in heat transfer rates and system efficiency. In addition to the knowledge of the thermal conductivity of the deposits it is necessary to obtain information on the thermal radiation characteristics of the furnace walls to predict the influence of ash sedimentation on heat transfer. At the Department of Energy Plant Technology investigations on the spectral emissivity of different coal ashes and slags were performed applying a spectral radiometer. The samples were electrically heated. Temperatures were varied between 600 and 1400 °C. Emissivities in the range of wavelengths from 1 to 15 μm have been determined. An essential result is that coal ashes show selective thermal radiation characteristics. The main factor of influence on the emissivity is the chemical composition. Therefore, measurements on the single phases SiO2, Al2O3 and MgO were carried out and compared with the emissivity of typical coal ashes and slags. Furthermore, the emissivity depends on temperature, mainly in the wavelength range from 1 to 6 μm.

scholarly journals Assessment of Graphitized Coal Ash Char Concentrates as a Potential Synthetic Graphite Source

Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 986
Author(s):  
Charlotte Badenhorst ◽  
Cláudia Santos ◽  
Juan Lázaro-Martínez ◽  
Barbara Białecka ◽  
Mihai Cruceru ◽  
...  
Keyword(s):  
Raw Materials ◽  
Coal Ash ◽  
Proximate Analysis ◽  
Raw Material ◽  
X Ray Diffraction ◽  
Natural Graphite ◽  
X Ray ◽  
Petrographic Analyses ◽  
Synthetic Graphite ◽  
Magnetic Resonance Scanning

Coal ash char concentrates from four countries (Portugal, Poland, Romania, and South Africa) were prepared, characterised, and graphitized under the scope of the Charphite project (Third ERA-MIN Joint Call (2015) on the Sustainable Supply of Raw Materials in Europe). Coal ash chars may be a secondary raw material to produce synthetic graphite and could be an alternative to natural graphite, which is a commodity with a high supply risk. The char concentrates and the graphitized material derived from the char concentrates were characterised using proximate analysis, X-ray fluorescence, X-ray diffraction (structural), Raman microspectroscopy, solid-state nuclear magnetic resonance, scanning electron microscopy, and petrographic analyses to determine if the graphitization of the char was successful, and which char properties enhanced or hindered graphitization. Char concentrates with a lower proportion of anisotropic particles and a higher proportion of mixed porous particles showed greater degrees of graphitization. It is curious to see that embedded Al2O3 minerals, such as glass and clay, influenced graphitization, as they most likely acted as catalysts for crystal growth in the basal direction. However, the graphitized samples, as a whole, do not compare well against a reference natural graphite sample despite some particles in select char concentrates appearing to be graphitized following graphitization.

scholarly journals Relationship between Chemical Composition and Nematicidal Activity of Different Essential Oils

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1546
Author(s):  
Trifone D’Addabbo ◽  
Maria Pia Argentieri ◽  
Sebastiano Laquale ◽  
Vincenzo Candido ◽  
Pinarosa Avato
Keyword(s):  
Chemical Composition ◽  
Essential Oils ◽  
Raw Materials ◽  
Nematicidal Activity ◽  
In Vitro Assays ◽  
Root Knot Nematode ◽  
Tomato Roots ◽  
Nematode Eggs ◽  
The Relationship

In this study, the relationship between nematicidal activity and chemical composition of ten essential oils (EOs) from different plant species was investigated both in in vitro assays on juveniles (J2) and eggs of the root-knot nematode Meloidogyne incognita and in experiments on tomato in soil infested by M. incognita. Nematode J2 were exposed for 4, 8 or 24 h to 0.78–100 μg mL−1 concentrations of each EO, whereas 24, 48 or 96 h exposures to 250, 500 and 1000 μg mL−1 solutions were tested on M. incognita egg masses. Treatments with 50, 100 or 200 μg kg soil rates of each EO were applied in the experiment on potted tomato. The highest nematicidal potential resulted for the C. verum EO, as highly toxic to both M. incognitaJ2 and eggs and strongly suppressive on nematode multiplication on tomato roots. The infestation of M. incognita on tomato roots was also strongly reduced by the EOs from E. citriodora and S. aromaticum, both highly toxic to M. incognitaJ2 but less active on nematode eggs. Adversely, R. graveolens EO strongly inhibited the egg hatch but was limitedly toxic to the infective J2. Chemical composition of the EOs was determined by GC-FID and GC-MS. The ten EOs showed a very different chemical composition in terms of major phytochemicals, with one or two dominant components totally amounting up to 85%. The structure–activity relationship based on the main phytochemicals identified in the assayed EOs and their nematicidal effects on M. incognita was also discussed. Results from this study confirmed that the selection of suitable EO raw materials can lead to the formulation on new effective nematicidal products.

scholarly journals Use of sewage sludge in concrete industry

2021 ◽  
Vol 18 (5) ◽  
pp. 566-575
Author(s):  
I. L. Chulkova ◽  
O. E. Smirnova ◽  
A. V. Krasova
Keyword(s):  
Chemical Composition ◽  
Sewage Sludge ◽  
Experimental Work ◽  
Building Material ◽  
Building Materials ◽  
Raw Materials ◽  
Physical And Mechanical Properties ◽  
National Standards ◽  
Actual Problem ◽  
The Relationship

Introduction. The article deals with the actual problem of disposal of industrial waste (sewage sludge). According to the literature data, possible directions of the use of sewage sludge in the production of building materials are identified and considered. Special attention is paid to the proposed variant of systematization of materials, which is based on the dependence of the aggregate state of the sediment on the type of building material. It is proposed to use sewage sludge as a complex additive to improve rheological properties at all stages of heavy concrete hardening.Methods and materials. Studies of the basic properties of raw materials and concrete based on them were determined using standard methods and the requirements of national standards. The material and chemical composition of the sediments, their physical and mechanical characteristics were determined on the basis of the laboratory of the plant of chemical concentrates (Novosibirsk).Results. As a result of the experimental work, the optimal percentage of sewage sludge in the composition of heavy concrete was determined, as well as the ratio of the chemical modifying additive, the optimal composition of concrete was investigated.Conclusion. As a result of the experimental work, the influence of the introduction of sewage sludge modified with plasticizing additives into the concrete composition was established. It has been established that sewage sludge is advisable to use in heavy concrete as a corrective additive without reducing the strength characteristics. In further studies, it is planned to solve the problems of structure formation and study of the interface between the phases of sewage sludge in the composition of concrete; to investigate the relationship between the chemical composition of precipitation and the physical and mechanical properties of a building material.

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