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Tytuł:
Chemical and morphological characterization of polymetallic (Mn-Fe) nodules from the Clarion-Clipperton Zone in the Pacific Ocean
Autorzy:
Kozłowska-Roman, Agata
Mikulski, Stanisław
Powiązania:
https://bibliotekanauki.pl/articles/2058694.pdf
Data publikacji:
2021
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
polymetallic nodules
critical elements
rare earth elements
deep-sea mining
Clarion-Clipperton Fracture Zone
Pacific
Opis:
Geochemical studies (WD-XRF, ICP-MS, and GF-AAS) have shown that polymetallic nodules from the eastern Clarion-Clipperton Zone (CCZ) in the Pacific Ocean are enriched in several metals such as Cu (mean 1.16%), Ni (1.15%), Co (0.15%), and Zn (0.14%), as well as remarkable contents of Mo (0.059%), V (0.04%), Ce (0.019%), Nd (0.011%), Li (0.015), and Pt (43 ppb). The average content of REE, together with Y and Sc, is 620 ppm. In nodules from the CCZ metal concentrations are often much higher than those reported in nodules from other ocean basins in the world. The bulk-nodule mean value of the Mn/Fe ratio is 5.3, which is characteristic for a mixed (hydrogenetic and diagenetic) origin of the nodules. Microprobe investigation revealed two different chemical compositions of the layers, and ascertained their general metal content. The nodules analyzed are composed mainly of concentric-collomorphic laminae of Mn and Fe (oxy)hydroxides which crystallized around mineral nuclei (e.g., quartz, clay minerals), bioclasts or rock fragments. They are from 3.3 to 7.6 cm in diameter. The chemical and physical properties of the laminae allowed distinction of two genetic types: hydrogenetic and diagenetic. Those formed as a result of hydrogenesis had increased values of Co, Si, Cl and S, while formed diagenetically showed increased levels of Cu, Ni, Mg, Zn and K. These lamina types are characterized by different growth structures, reflectivity, density and Mn/Fe ratios. The ratio of the diagenetic layers to hydrogenetic layers (192/53) in representative polymetallic nodules shows that the nodules of this study are of mixed hydrogenetic-diagenetic type. A mixed genesis was also shown by discriminant diagrams, with these CCZ samples being located at the transition between typical hydrogenetic and diagenetic fields.
Źródło:
Geological Quarterly; 2021, 65, 4; 177--194
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characteristics of the Ahmadabad hematite/barite deposit, Iran – studies of mineralogy, geochemistry and fluid inclusions
Autorzy:
Babaei, A. H.
Ganji, A.
Powiązania:
https://bibliotekanauki.pl/articles/94546.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
geochemistry
trace elements
rare earth elements
Semnan
geochemia
pierwiastki śladowe
pierwiastki ziem rzadkich
REE
Opis:
The Ahmadabad hematite/barite deposit is located to the northeast of the city of Semnan, Iran. Geostructurally, this deposit lies between the Alborz and the Central Iran zones in the Semnan Subzone. Hematite-barite mineralisation occurs in the form of a vein along a local fault within Eocene volcanic host rocks. The Ahmadabad deposit has a simple mineralogy, of which hematite and barite are the main constituents, followed by pyrite and Fe-oxyhydroxides such as limonite and goethite. Based on textural relationships between the above-mentioned principal minerals, it could be deduced that there are three hydrothermal mineralisation stages in which pyrite, hematite and barite with primary open space filling textures formed under different hydrothermal conditions. Subsequently, in the supergene stage, goethite and limonite minerals with secondary replacement textures formed under oxidation surficial conditions. Microthermometric studies on barite samples show that homogenisation temperatures (TH) for primary fluid inclusions range from 142 to 256°C with a temperature peak between 200 and 220°C. Salinities vary from 3.62 to 16.70 NaCl wt% with two different peaks, including one of 6 to 8 NaCl wt% and another of 12 to 14 NaCl wt%. This indicates that two different hydrothermal waters, including basinal and sea waters, could have been involved in barite mineralisation. The geochemistry of the major and trace elements in the samples studied indicate a hydrothermal origin for hematite and barite mineralisation. Moreover, the Fe/Mn ratio (>10) and plots of hematite samples of Ahmadabad ores on Al-Fe-Mn, Fe-Mn-(Ni+Co+ Cu)×10, Fe-Mn-SiX2 and MnO/TiO2 – Fe2O3/TiO2 diagrams indicate that hematite mineralisation in the Ahmadabad deposit occurred under hydrothermal conditions. Furthermore, Ba and Sr enrichment, along with Pb, Zn, Hg, Cu and Sb depletion, in the barite samples of Ahmadabad ores are indicative of a low temperature hydrothermal origin for the deposit. A comparison of the ratios of LaN/YbN, CeN/YbN, TbN/LaN, SmN/NdN and parameters of Ce/Ce* and La/La* anomalies of the hematite, barite, host volcanic rocks and quartz latite samples to each other elucidate two important points: 1) the barite could have originated from volcanic host rocks, 2) the hematite could have originated from a quartz latite lithological unit. The chondrite normalised REE patterns of samples of hematite barite, volcanic host rocks and quartz latite imply that two different hydrothermal fluids could be proposed for hematite and barite mineralisation. The comparison between chondrite normalised REE patterns of Ahmadabad barite with oceanic origin barite and low temperature hydrothermal barite shows close similarities to the low temperature hydrothermal barite deposits.
Źródło:
Geologos; 2018, 24, 1; 55-68
1426-8981
2080-6574
Pojawia się w:
Geologos
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Possibilities of recovery and separation of rare earth elements
Autorzy:
Fila, Dominika
Powiązania:
https://bibliotekanauki.pl/articles/2079965.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Tematy:
rare earth elements
resources
recovery
separation
Opis:
Rare earth metals are a group of elements widely used in high technology products. They are included in the group of critical mineral resources for the EU economy. Rare earth elements are found in computers and mobile phones, as well as in low-emission energy technologies. They are also applied in chemical processes as catalysts in the oil refining. Some of them occur even in considerable quantities in the earth's crust but not very often in the concentrations justifying the profitability of their extraction. Additionally, the constantly growing demand and the current market situation cause that alternative resources of rare earth elements recovery are sought after. Therefore, the recovery and separation methods as well as recovery from the secondary sources are becoming more and more important. The following paper presents the possibilities of recovery and separation of rare earth elements from primary and secondary sources.
Źródło:
Annales Universitatis Mariae Curie-Skłodowska, sectio AA – Chemia; 2018, 73, 1; 99-110
2083-358X
Pojawia się w:
Annales Universitatis Mariae Curie-Skłodowska, sectio AA – Chemia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Lithologically-related rare earth element variations the Mio-Pliocene Poznań Formation (Poland)
Autorzy:
Retka, J.
Powiązania:
https://bibliotekanauki.pl/articles/2059369.pdf
Data publikacji:
2018
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Poznań Formation
rare earth elements
clay lithotypes
Opis:
Concentrations of rare earth elements (REEs) were determined in 129 clay samples collected from the Mio-Pliocene Poznań Formation in Poland. The REEs occur in a relatively wide range from 58.2 to 1,709 mg/kg. Low North American Shale Composite (NASC)-normalized total REE contents with heavy rare earth element (HREE) depletion were noted in most of the samples analysed. Small variations were detected in the REE contents in the lithologies distinguished. Red clays are characterised by slightly lower REE concentrations relative to green and grey clays. All the Poznań Formation clays exhibit a negative Eu anomaly when normalized to the average of chondrites. Values increase according to the following sequence: grey clays < red clays < green clays. The NASC-normalized REE concentration curves show a positive Eu anomaly. The LaNASC/YbNASC ratio indicates HREE depletion. A small variation in this ratio was observed in the sequence green clays > grey clays > red clays. The variability of the REE contents of the Poznań Formation decreased from west to east.
Źródło:
Geological Quarterly; 2018, 62, 1; 146--154
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Leaching kinetic study of Y and Eu from waste phosphors using hydrochloric acid solution containing hydrogen peroxide
Autorzy:
Yu, M.
Jiang, Z.
Mei, G.
Chen, X.
Powiązania:
https://bibliotekanauki.pl/articles/949690.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
waste phosphors
leaching
kinetics
rare earth elements
Opis:
The leaching kinetics of Y and Eu from waste phosphors using a hydrochloric acid (HCl) solution containing hydrogen peroxide (H2O2) were investigated. Characterization of the waste phosphors was performed using XRD to ascertain the phases as (Y0.95Eu0.05)2O3 (red phosphors), (Ce0.67Tb0.33)MgAl11O19 (green phosphors), (Ba0.9Eu0.1)Mg2Al16O27 (blue phosphors), and SiO2 (quartz). The influence of factors such as HCl concentration, addition amount of H2O2, temperature, and reaction time on the leaching performance of Y and Eu was investigated. The maximum leaching recoveries of Y (99.87%) and Eu (88.72%) were obtained at 4 M HCl, 0.2 cm3/g H2O2, 60 ℃ temperature, and 180 min of reaction time at a liquid-to-solid ratio of 7.5 cm3/g. Leaching kinetic results showed the best fit with the shrinking sphere model (1-(1-x)1/3)=kct), ensuring that the overall leaching process was governed by a chemical control mechanism. Activation energies of 42.35 and 33.28 kJ/mol were acquired for leaching of Y and Eu, respectively, at 40-70 ℃, which further supports the proposed chemical control leaching process.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 2; 238-248
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Solubility of Eskisehir thorium/rare earth ores in sulphuric and nitric acids
Autorzy:
Kursun, I.
Tombal, T. D.
Terzi, M.
Powiązania:
https://bibliotekanauki.pl/articles/109924.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
thorium
rare earth elements
bastnaesite
leaching
solubility
Opis:
Nuclear energy is considered as one of the most important energy resources in the world. Thorium (Th) has a significant potential to be used in electricity production by nuclear energy since its existence is not depended on the presence of another radioactive elements, and it has larger potential reserves than uranium. Bastnaesite ((Ce, La)CO3F) is one of the minerals from which Th can be economically extracted. In this study, solubility of bastnaesite containing ore obtained from Eskisehir, Turkey was investigated by leaching with H2SO4 and HNO3 in terms of leaching performance of thorium and some rare-earth elements (Ce, Nd, La). In this context, representative samples were taken from three different areas in Eskisehir-Kizilcaoren region, and a composite sample was prepared to be used for the leaching experiments. The effects of several parameters such as the solid ratio, leaching time, acid amount and pulp temperature, on dissolution efficiencies of Th, Nd, Ce and La was investigated. The best results were obtained using 3.42 mol/dm3 HNO3, solid–to–liquid ratio of 35%, 120 min leaching time and 60 oC temperature. Under these optimum conditions, the dissolution efficiencies of Th, Ce, Nd, and La were obtained as 94%, 82%, 77% and 70%, respectively.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 2; 476-483
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Phytoextraction of rare earth elements
Autorzy:
Gmur, Dominika
Siebielec, Grzegorz
Powiązania:
https://bibliotekanauki.pl/articles/2143646.pdf
Data publikacji:
2022-09
Wydawca:
Instytut Uprawy Nawożenia i Gleboznawstwa – Państwowy Instytut Badawczy
Tematy:
rare earth elements
phytoextraction
hyperaccumulation
environmental remediation
Opis:
Rare earth elements (REE) are a group of 17 elements with similar physicochemical properties. Most of the world’s REE extraction belongs to China. Due to the growing demand for REE and limited resources, the European Commission has identified REE as critical materials. On the other hand, little is known so far about the possible effects of long-term exposure of living organisms and the ecosystem to REE. Therefore, potential solutions for the recovery of distributed REE are being sought. Phytoextraction is a method that allows the recovery of elements from the environment. For this purpose, two strategies are gener- ally used: the use of plants with the natural ability to accumulate REE (hyperaccumulators) and the support of the process through the use of chelators. Twenty two species have been identified as REE hyperaccumulators, e.g. Phytolacca americana, Dicranop- teris linearis, Blechnum niponicum or Carya tomentosa. For the total REE, an accumulation limit of 100 mg kg-1 dry weight was established. Natural chelators are used as additives, e.g. humic acids or low molecular weight acids, as well as synthetic ones: EDTA or EGTA. In addition, the efficiency of the process is also influenced by other factors, such as the sorption capacity of the soil, the content of organic matter in the soil or soil pH. The aim of this article is to present the plant species useful in REE phy- toextraction and the potential for enhancing the method with the use of chelators.
Źródło:
Polish Journal of Agronomy; 2022, 50; 3-11
2081-2787
Pojawia się w:
Polish Journal of Agronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The recycling-oriented material characterization of hard disk drives with special emphasis on NdFeB magnets
Autorzy:
Dańczak, A.
Chojnacka, I.
Matuska, S.
Marcola, K.
Leśniewicz, A.
Wełna, M.
Żak, A.
Adamski, Z.
Rycerz, L.
Powiązania:
https://bibliotekanauki.pl/articles/109315.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
hard disk drives
rare earth elements
permanent magnets
recycling
Opis:
Hard disk drives (HDDs) consist of many components made from various materials: e.g. aluminum, steel, copper and rare earth elements (REEs). Recycling and reuse of these materials is desirable for economic and environmental reasons. Developing of potential HDDs recycling methods requires knowledge about HDDs material characteristic. The study aims to explore knowledge about structure and chemical composition of HDDs main components with special emphasis on NdFeB magnets. HDDs collected for the experiments came from Desktop PCs and Notebooks. The dependence between the average mass of HDDs components and such parameters as producer, year and country of production and disk capacity was analyzed. Chemical composition of NdFeB magnets and the heaviest components (i.e. top cover, mounting chassis, platters and metallic plates from magnet assembly of actuator) was analyzed by various analytical methods. The heaviest HDDs main components: top cover and mounting chassis, with the highest recycling potential, are made of aluminum and steel respectively. The majority of HDDs components showed also the existence of different alloy additions: C, Mg, Si, P, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Sn and Pb. NdFeB magnets constitute 2.2 ± 1.1% of the average HDD from Desktop PC (517.3 ± 64.2 g) and 3.2 ± 1.2% from Notebook (108.2 ± 24.3 g). The chemical composition of NdFeB magnets from collected HDDs changes in the wide range: Fe (53–62%), Nd (25–29%), Pr (2–13%), Dy (0.1– 1.4%), Ni (2–6%), Co (0.5–3.6%), B (0.8–1.0%). Recycling of permanent magnets based on NdFeB alloys is potential remedy to fill the gap in the supply of rare earth elements on the global REEs market.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 2; 363-376
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Complex Processing of Phosphogypsum - a Way of Recycling Dumps with Reception of Commodity Production of Wide Application
Autorzy:
Lutskiy, D.
Litvinova, T.
Ignatovich, A.
Fialkovskiy, I.
Powiązania:
https://bibliotekanauki.pl/articles/124643.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
phosphogypsum
utilization
building materials
agriculture
rare earth elements
conversion
Opis:
The article analyzes the information on modern developments in the utilization of phosphogypsum. Only a few directions give the prospect of large-scale use of both freshly formed phosphogypsum and phosphogypsum accumulated in dumps. Under the conditions of the Russian Federation, it is promising to use phosphogypsum for the production of building materials, as well as for agriculture, for reclamation of soil and the creation of mounds of a certain type. The possibility of using phosphogypsum as a raw material for obtaining rare-earth elements is shown.
Źródło:
Journal of Ecological Engineering; 2018, 19, 2; 221-225
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Magnet Scrap Size on the Extraction Behavior of Heavy Rare Earth Elements by Liquid Metal Extraction
Autorzy:
Nam, Sun-Woo
Rasheed, Mohammad Zarar
Park, Sang-Min
Lee, Sang-Hoon
Kim, Do-Hyang
Kim, Taek-Soo
Powiązania:
https://bibliotekanauki.pl/articles/355705.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
liquid metal extraction
rare earth elements
recycling
oxidation
magnet scrap
Opis:
Liquid metal extraction (LME) process results in 100% neodymium (Nd) extraction but the highest extraction efficiency reportedfor Dysprosium (Dy) so far is 74%. Oxidation of Dy is the major limiting factor for incomplete Dy extraction. In order to enhance the extraction efficiency and to further investigate the limiting factors for incomplete extraction, experiments were carried out on six different particle sizes of under 200 μm, 200-300 μm, 300-700 μm, 700-1000 μm, 1000-2000 μm and over 2000 μm at 900°C with magnesium-to-magnet scrap ratio of 15:1 for 6, 24 and 48 hours, respectively. This research identified Dy2 Fe17 in addition toDy2 O3 phase to be responsible for incomplete extraction. The relationship between Dy2 Fe17 and Dy2O3 phase was investigated, and the overall extraction efficiency of Dy was enhanced to 97%.
Źródło:
Archives of Metallurgy and Materials; 2020, 65, 4; 1273-1276
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of alkali processing for the recycling of rare earth values from spent fluorescent lamps
Autorzy:
Shukla, Neha
Tanvar, Himanshu
Dhawan, Nikhil
Powiązania:
https://bibliotekanauki.pl/articles/1449193.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
fluorescent lamps
rare earth elements
activation energy
recovery
cerium
terbium
Opis:
Phosphor samples collected after crushing and sieving of discarded fluorescent lamps comprise approximately 31 % rare earth elements in the form of $Y_{1.90}Eu_{0.10}O_3$, $Al11Ce_{0.67}MgO_{19}Tb_{0.33}$, and $Al_{10.09}Ba_{0.96}Mg_{0.91}O_{17}$: $Eu^{2+}$ phase. Direct leaching and mechanical activation assisted leaching are incapable of recovering $Ce$, $Tb$ values from the $Al_{11}Ce_{0.67}MgO_{19}Tb_{0.33}$ phase. Heat treatment with $NaOH$ was found successful for dissociation of $Ce$, $Tb$ phase via substitution of rare-earth ion by $Na^+$ ion to form rare earth oxide and water-soluble $NaAlO_2$. $Y$, $Eu$, $Ce$, and $Tb$ values were recovered from heattreated mass in a two-step leaching process followed by recovery from the leach solution by oxalic acid precipitation. Over 95 % extraction rate was attained after heat treatment at 400 °C with 150 wt-% $NaOH$ for 1 h. It was found that $Y$, $Eu$ containing phase does not take part in the heat treatment process whereas the $Ce$, $Tb$ phase undergoes a solid-state chemical reaction with $NaOH$ via product layer diffusion model with 41.5 kJ/mol activation energy. Approximately 15 g mixed oxide (purity >95 %) of $Y$ (79 %), $Eu$ (7 %), $Ce$ (5 %), and $Tb$ (4 %) could be recovered from 100 units of discarded FLs. Microwave treatment of phosphor and $NaOH$ (50 wt-%) yielded approximately 42 % $Y$, 100 % $Eu$, 65 % $Ce$, and 70 % Tb recovery in just 5 min. Approximately 9 g of REO and 5 g of cerium enriched leach residue were recovered from the microwave route within 5 min and depicted high microwave potential application in the recovery of $Ce$ and $Tb$ values from waste phosphor sample.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 4; 710-722
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Separation of rare earth elements from the leaching solution of waste phosphors by solvent extraction with Cyanex 272 and its mixture with Alamine 336
Autorzy:
Xing, Weidong
Lee, Man Seung
Powiązania:
https://bibliotekanauki.pl/articles/1449503.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
phosphors
rare earth elements
HCl solution
solvent extraction
Cyanex 272
Opis:
Waste phosphors contain rare earth elements (REEs) such as yttrium (Y), europium (Eu), cerium (Ce), terbium (Tb) and lanthanum (La). Separation of these REEs from the leaching solution of waste phosphors was investigated by solvent extraction with single Cyanex 272, binary mixture (mixture of Cyanex 272 and Alamine 336), ionic liquid (prepared by Cyanex 272 and Aliquat 336) in kerosene. The effect of solution pH and extractants concentration was mainly investigated. The results indicated that Y(III) was selectively extracted by single Cyanex 272 over the other four REEs from the HCl solution with initial pH range from 3 to 5. Synergistic extraction with the binary mixture was enough for the extraction of Y(III), Tb(III) and Eu(III) with a small amount of Ce(III). Scrubbing with pure Y(III) solution with intermediate acidity was effective in scrubbing Ce(III) from the loaded binary mixture organic phase. Stripping behavior of the Y(III), Tb(III) and Eu(III) by HCl solution was similar to each other. Tb(III) and Eu(III) can be separated by extraction with the binary mixture followed by scrubbing with pure Tb(III) solution. McCabe-Thiele diagrams were constructed for the extraction of Y(III) by single Cyanex 272 and that of Tb(III) by the mixture. A process was proposed for the separation of REEs from the leaching solution of waste phosphors by solvent extraction.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 1; 184-194
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative analysis of soil magnetic susceptibility and concentration of rare earth elements in soil of problematic areas
Autorzy:
Zawadzki, Jarosław
Fabijańczyk, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/2064859.pdf
Data publikacji:
2019
Wydawca:
STE GROUP
Tematy:
soil pollution
rare earth elements
magnetometry
magnetic susceptibility
industrial areas
Opis:
Soil contamination with rare earth metals (REE) can have both direct and indirect connection with industrial activity and ore-exploration. In the studies conducted so far, the presence of rare earth elements in coal seams, coal combustion waste as well as fly ash was found. It is important that detailed studies of the REE content in soil were not carried out in Poland. Until now, in a few studies, a high content of cerium and lanthanum was found in relation to the average content of the torn ones in the world. This work focuses on the areas under the influence of the industry associated with the extraction and combustion of hard coal, but also with other types of industry. Analyzes of REE content in soil were conducted in selected areas of the Upper Silesian Industrial Region and Norway, located near the Bjornevatn mine. In study areas, soil samples were collected and used for chemical and magnetometric measurements. Firstly, concentrations of REE were determined, and after that soil samples were used to measure soil magnetic susceptibility. Finally, statistical analyses were performed in order to check the correlation between REE concentrations in soil and soil magnetic susceptibility.
Źródło:
Multidisciplinary Aspects of Production Engineering; 2019, 2, 1; 81--90
2545-2827
Pojawia się w:
Multidisciplinary Aspects of Production Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High-temperature carbothermal dephosphorization of Malaysian monazite
Autorzy:
Udayakumar, Sanjith
Sheikh Abdul Hamid, Sheikh Abdul Rezan
Baharun, Norlia
Pownceby, Mark
Powiązania:
https://bibliotekanauki.pl/articles/2146886.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
malaysian monazite concentrate
dephosphorization
carbothermal reduction
rare earth elements
graphite
Opis:
High-temperature carbothermal reduction experiments with graphite powder were conducted to assess the dephosphorization behavior of Malaysian monazite concentrate. Thermodynamic analysis of the possible dephosphorization reactions was conducted to evaluate the feasibility of the carbothermal reduction of the monazite phases. The effects of temperature, particle size, and monazite to carbon ratio were then investigated under different conditions. The carbothermal reduction experiments were conducted based on the Taguchi design method, and up to 97% of phosphorous removal was achieved under optimized conditions. The optimal conditions for dephosphorization were determined as; a reduction temperature of 1350 °C, a particle size of -75 μm, and monazite to carbon molar ratio of 0.3. Microstructural and phase characterization of the dephosphorized products revealed that CeO2, Nd2O3, La2O3, and Pr2O3 oxide phases were prominent, and no residual peaks of monazite remained in the reduced products. The information gained from the study can aid in the design of a suitable post-dephosphorization hydrometallurgical treatment for exploiting Malaysian monazite as a local source of REEs.
Źródło:
Physicochemical Problems of Mineral Processing; 2021, 57, 6; 140--155
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Distribution of Trace Elements, Rare Earth Elements and Ecotoxicity in Sediments of the Kosva Bay, Perm Region (Russia)
Autorzy:
Ushakova, Evgeniya
Menshikova, Elena
Blinov, Sergey
Vaganov, Sergey
Perevoshchikov, Roman
Powiązania:
https://bibliotekanauki.pl/articles/2086373.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
trace element
rare earth elements
sedimentation
bottom sediment
ecotoxicity
acid mine drainage
Opis:
Over a long period of time, a huge amount of technogenic bottom sediments has been accumulating in the Kosva Bay with significant concentrations of amorphous iron and aluminium hydroxides, which, in turn, are active sorbents of pollutants. This study examines the distribution of trace elements and rare earth elements and their toxicity in the Kosva Bay of the Kama Reservoir (Perm Region, Russia). In the middle reach, the Kosva River crosses the Kizel coal basin, where acid mine water is discharged from closed mines. The average content of trace elements in the samples of bottom sediments of the bay varies from 0.10 mg/kg (Se) to 176.36 mg/kg (Ba). The amount of rare earth elements varies from 66.8 to 83.6 mg/kg. The ecological significance of trace elements and rare earth elements was studied using an element-by-element assessment (EF and Igeo), Potential Ecological Risk Index (RI), Mean Probable Effect Concentration Quotient (PECQ), and two bioassays (Daphnia magna Straus and Scenedesmus quadricauda (Turp.) Breb. The highest Hg enrichment was found at two sampling points. Taking into account the average value of Igeo, the pollution by Co, V, Nb, Hg, Sn, Zn, Sm, Ni, Cr, and Gd is the highest and corresponds to extremely contaminated category. The RI values indicate that pollution categories vary from moderate risk to considerable risk. According to mean PECQ values, bottom sediments of the bay have moderate potential toxicity towards biological communities. Results of chronic and acute toxicity on test objects D. magna and Scenedesmus quadricauda Breb show the water extract from bottom sediments having no effects on the test objects. The results of the study show that in order to assess the quality of bottom sediments, an integrated approach, combining chemical and ecotoxicological analyses, is needed.
Źródło:
Journal of Ecological Engineering; 2022, 23, 4; 1--16
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 44

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