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1

Rare earth elements, uranium, and thorium in ashes from biomass and hard coal combustion/co-combustion

Adamczyk Joanna, Smołka-Danielowska Danuta, Krzątała Arkadiusz, Krzykawski Tomasz

Gospodarka Surowcami Mineralnymi

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2023

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T. 39, z. 2

87--108

EN

This study presents the results of concentrations of rare earth elements and yttrium (REY), uranium (U), and thorium (Th) in ashes from combustion/co-combustion of biomass (20%, 40%, and 60% share) from the agri-food industry (pomace from apples, walnut shells, and sunflower husks) and hard coal. The study primarily focuses on ashes from the co-combustion of biomass and hard coal, in terms of their potential use for the recovery of rare earth elements (REE), and the identification of the sources of these elements in the ashes. Research methods such as ICP-MS (inductively coupled plasma mass spectrometry), XRD (X-ray diffraction), and SEM-EDS (scanning electron microscopy with quantitative X-ray microanalysis) were used. The total average content of REY in ash from biomass combustion is 3.55-120.5 mg/kg, and in ash from co-combustion, it is from 187.3 to 73.5 mg/kg. The concentration of critical REE in biomass combustion ash is in the range 1.0-38.7 mg/kg, and in co-combustion ash it is 23.3-60.7 mg/kg. In hard-coal ash, the average concentration of REY and critical REY was determined at the level of 175 and 45.3 mg/kg, respectively. In all samples of the tested ashes, a higher concentration of Th (0.2-14.8 mg/kg) was found in comparison to U (0.1-6 mg/kg). In ashes from biomass and hard-coal combustion/co-combustion, the range of the prospective coefficient (Coutl) is 0.66-0.82 and 0.8-0.85, respectively, which may suggest a potential source for REE recovery. On the basis of SEM-EDS studies, yttrium was found in particles of ashes from biomass combustion, which is mainly bound to carbonates. The carriers of REY, U, and Th in ashes from biomass and hard-coal co-combustion are phosphates (monazite and xenotime), and probably the vitreous aluminosilicate substance.

PL

W pracy przedstawiono wyniki stężeń pierwiastków ziem rzadkich i itru (REY), uranu (U), oraz toru (Th) w popiołach ze spalania/współspalania biomasy (udział 20, 40 i 60%) z przemysłu rolno-spożywczego (wytłoki z jabłek, łupiny orzecha włoskiego i łuski słonecznik), i węgla kamiennego. W pracy zwrócono uwagę przede wszystkim na popioły ze współspalania biomasy i węgla kamiennego, pod kątem ich potencjalnego wykorzystania do odzysku pierwiastków ziem rzadkich (REE), oraz identyfikacji źródeł tych pierwiastków w popiołach. Zastosowano metody badawcze takie jak ICP-MS (spektrometria mas ze wzbudzeniem w plazmie indukcyjnie sprzężonej), XRD (dyfrakcja rentgenowska) i SEM-EDS (skaningowa mikroskopia elektronowa z ilościową mikroanalizą rentgenowską). Całkowita średnia zawartość REY w popiołach ze spalania biomasy wynosi 3,55-120,5 mg/kg, a w popiołach ze współspalania od 73,5 do 187,3 mg/kg. Średnie stężenie krytycznych REE w popiołach ze spalania biomasy mieści się w zakresie 1,0-38,7 mg/kg, a w popiołach ze współspalania 23,3-60,7 mg/kg. W popiele z węgla kamiennego średnie stężenie REY i krytycznych REY oznaczono odpowiednio na poziomie 175 i 45.3 mg/kg. W próbkach badanych popiołów oznaczono wyższe stężenie Th (0,2-14,8 mg/kg), w porównaniu do U (0,1-6 mg/kg). W popiołach ze spalania/współspalania biomasy i węgla kamiennego zakres wartości współczynnika perspektywicznego (Coutl) wynosi odpowiednio 0,66-0,82 i 0,8-0,85, co może sugerować potecjalne źródło do odzysku REE. Analiza cząstek popiołów ze spalania biomasy wykazała itr, który związany jest głównie z węglanami. Nośnikami REY, U i Th w popiołach ze współspalania biomasy i węgla kamiennego są fosforany: monacyt i ksenotym, oraz prawdopodobnie szklista substancja glinokrzemianowa.

2

Electrochemical behavior and morphology of selected sintered samples of Mg65Zn30Ca4Pr1 alloy

Hrapkowicz Bartłomiej, Lesz Sabina, Drygała Aleksandra, Karolus Małgorzata, Gołombek Klaudiusz, Babilas Rafał, Popis Julia, Gabryś Adrian, Młynarek-Żak Katarzyna, Garbiec Dariusz

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2023

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Vol. 71, nr 3

art. no. e145564

EN

In order to investigate the effect of the milling time on the corrosion resistance of the Mg65Zn30Ca4Pr1 alloy, powders of the alloy were prepared and milled for 13, 20, and 70 hours, respectively. The samples were sintered using spark plasma sintering (SPS) technology at 350◦C and pressure of 50 MPa. The samples were subjected to potentiodynamic immersion tests in Ringer’s solution at 37◦C. The obtained values of Ecorr were –1.36, –1.35, and –1.39 V, with polarization resistance Rp = 144, 189, and 101 Ω for samples milled for 13, 20 and 70 h, respectively. The samples morphology showed cracks and pits, thus signaling pitting corrosion.

3

Stratigraphy of the Albian-Cenomanian (Cretaceous) phosphorite interval in central Poland: a reappraisal

Machalski Marcin, Olszewska-Nejbert Danuta, Wilmsen Markus

Acta Geologica Polonica

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2023

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Vol. 73, no. 1

1--31

EN

Several closely-spaced phosphorite beds stand out at the Albian–Cenomanian transition in the mid-Cretaceous transgressive succession at the northeastern margin of the Holy Cross Mountains, central Poland. They form a distinctive condensed interval of considerable stratigraphical, palaeontological, and economic value. Here, we correlate the classical section at Annopol with a recently investigated section at Chałupki. We propose a new stratigraphic interpretation of the phosphorite interval, based on lithological correlations, Rare Earth Elements and Yttrium (REE+Y) signatures of phosphorites, age-diagnostic macrofossils, and sequence stratigraphic patterns. This interval has long been considered as exclusively Albian in age. However, new macrofossil data allow us to assign the higher phosphorite levels at Annopol and Chałupki, which were the primary target for the phosphate mining, to the lower Cenomanian. In terms of sequence stratigraphy, the phosphorite interval encompasses the depositional sequence DS Al 8 and the Lowstand System Tract of the successive DS Al/Ce 1 sequence. The proposed correlation suggests that lowstand reworking during the Albian–Cenomanian boundary interval played an important role in concentrating the phosphatic clasts and nodules to exploitable stratiform accumulations. Our conclusions are pertinent to regional studies, assessments of natural resources (in view of the recent interest in REE content of the phosphorites), and dating of the fossil assemblages preserved in the phosphorite interval. On a broader scale, they add to our understanding of the formation of stratiform phosphorite deposits.

4

Distribution of Trace Elements, Rare Earth Elements and Ecotoxicity in Sediments of the Kosva Bay, Perm Region (Russia)

Ushakova Evgeniya, Menshikova Elena, Blinov Sergey, Vaganov Sergey, Perevoshchikov Roman

Journal of Ecological Engineering

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2022

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Vol. 23, nr 4

1--16

EN

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.

5

Comparison of Sensitivity of Autotrophic and Heterotrophic Microorganisms to the Pollution of Natural Water with Rare Earth Elements (Lanthanum and Cerium)

Lozhkina Roza A., Olkova Anna S., Koval Ekaterina V., Tomilina Irina I., Sysolyatina Maria A.

Journal of Ecological Engineering

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2022

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Vol. 23, nr 4

58--63

EN

The purpose of the work was to compare the sensitivity of autotrophic and heterotrophic organisms used in bioassay to lanthanum and cerium under the conditions of a model experiment with aqueous media. Using bioassay methods, the pre-lethal effects of La and Ce in heterotrophic Paramecium caudatum and Escherichia coli, as well as autotrophic Chlorella vulgaris and Nostoc linckia were determined. Model solutions of La2 (SO4)3∙8H2O and Ce2 (SO4)3∙8H2O were tested in the concentration range of 0.1–200 mg/l. As a result, it was shown that heterotrophic organisms are more sensitive to water pollution with La and Ce than autotrophic ones. According to the totality of experiments, cerium turned out to be more toxic than lanthanum. When planning the environmental studies of wastewater or reservoirs polluted with REE, it is recommended to focus on comparative sensitivity of bioassay methods, taking into account the test-functions used: bioassay for chemotaxis of P. caudatum > bioassay for changes in bioluminescence of E. coli (strain M-17) > bioassay for the content of chlorophyll а and intensity of lipid peroxidation in N. linckia > bioassay on the increase in the number of Cl. vulgaris.

6

Rare earth elements in the Sin Quyen IOCG deposit, North Vietnam

Nguyen Dinh Chau, Pieczonka Jadwiga, Piestrzyński Adam, Khanh Phon Le, Duong Van Hao

Gospodarka Surowcami Mineralnymi

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2022

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T. 38, z. 1

17--60

EN

The Sin Quyen deposit is characterized by a high accumulation of rare earth elements (REE). This deposit belongs to the IOCG type copper deposits (Iron Oxide Copper-Gold Deposits). In the deposit, the REE carrier minerals have been identified as follow: allanite, titanite, uraninite, monazite, apatite, chevkinite, aeschynite, bastnäsite, and epidote. In the skarn zone, contents of allanite range from single percentages to 10% in hand-size specimens. Locally, minerals of epidote subgroup which occur in large amounts in the host rocks are important. The studied allanites have concentrations of: REE (14–27 wt%), Ca (9–16 wt%), Al (8–19 wt%), Si (26–34 wt%) and Fe (12–21 wt%). Two populations of allanite are documented, the first is texturally older and probably related to the Ca-K alteration (second stage of crystallization). This population has higher REE concentration ranging from 20 to 27 wt%. The second population is texturally younger and has a lower total REE concentration ranging from 14 to 19.9 wt%, which occur mostly as a rim surrounding the older and likely arose during the K alteration with Cu-Au mineralization (third crystallization). The chemical composition indicates that the studied allanites belong to the Ce-La-ferriallanite family, with low ΣHREE and an average of 0.21 wt.%. A temperature of 355°C which was calculated using a value of δ34S isotopes is interpreted as a temperature of the second crystallization stage of allanite. In the studied deposit, excluding allanite and titanite, the other bearing REE minerals have an insignificant role in the REE balance, since they either have the total content of REE, which is often close to the WDS detection limit (rf. the epidote subgroup), or their only occur at the single points. The content of total REE in accessory uraninites is high and range from 1.311% up to 7.959% with an average value of 4.852%.

XX

Złoże Sin Quyen charakteryzuje się wysoką zawartością pierwiastków ziem rzadkich (REE). Złoże to należy do typu złóż miedzi IOCG (Iron Oxide Copper-Gold Deposits). Zidentyfikowane minerały zawierające REE to: allanit, tytanit, uraninit, monacyt, apatyt, czewkinit, aeschynit, bastnäsyt i epidotyt. W próbkach wielkości dłoni, pobranych ze strefy skarnowej, zawartości allanitu wahają się od pojedynczych do 10%. Lokalnie, minerały podrzędnej grupy epidotytu są ważne z powodu ich licznego występowania. Badane allanity zawierają: REE (14–27 wt%), Ca (9–16% wag.), Al (8–19% wag.), Si (26–34% wag.) i Fe (12–21% wag.). Udokumentowano dwie populacje allanitu, pierwsza jest teksturalnie starsza i prawdopodobnie związana z alteracją Ca-K (drugi etap krystalizacji). Ta populacja ma wyższe koncentracje REE, które są zawarte w przedziale od 20 do 27% wag. Druga populacja jest młodsza i zawiera mniejsze ilości ziem rzadkich (od 14 do 19,9% wag.). Populacja ta występuje głównie w postaci obwódek regeneracyjnych, tworząc zrosty ze starszą populacją i jest związana z alteracją potasową oraz mineralizacją Cu-Au (trzeci etap krystalizacji). Skład chemiczny wskazuje, że badane allanity należą do podgrupy Ce-La-ferriallanitu, o niskiej i średniej koncentracji ΣHREE 0,21% wag. Temperatura krystalizacji 355°C, została obliczona na podstawie wartości δ34S. Ta temperatura jest interpretowana jako temperatura drugiego etapu krystalizacji. W badanym złożu, poza allanitami i tytanitami, inne minerały REE i ich nośniki mają małe znaczenie w bilansie ich zawartości. Na przykład sumaryczna zawartość REE w podrzędnie występującym epidocie, jest na poziomie wykrywalności metody WDS, a inne minerały, takie jak uraninit, czewkinit, aeschynit, czy bastnäsyt występują zbyt rzadko, aby wpływać na bilans tych metali. W akcesorycznym uraninicie, pomierzone zawartości REE wahają się w granicach 1,31–7,96%, przy średniej zawartości 4,85%.

7

Effect of Rare Earth Cerium Addition on Oxidation Behavior of Co-Al-W Alloys at 800°C

Migas Damian, Liptáková Tatiana, Moskal Grzegorz

Archives of Metallurgy and Materials

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2022

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Vol. 67, iss. 1

203--208

EN

The γ/γ′ Co-based alloys are a new class of cobalt superalloys, which are characterized by remarkable high temperature strength owing to strengthening by γ′-Co3(Al, X) phases. In this investigation, the effect of cerium addition on oxidation behavior of model Co-Al-W alloys was studied. The introduction of Ce aimed at improvement of the oxidation resistance of γ′-forming Co-based superalloys. The minor additions of cerium (0.1, 0.5 at.%) were added to the base alloy Co-9Al-9W. The alloys were prepared via induction vacuum melting (VIM). Further, a primary microstructure of the alloys was analyzed with particular regard to a segregation of Ce. The thermogravimetric analysis (TG) under non-isothermal conditions was used to preliminary estimate the oxidation behavior of alloys at different temperatures. During experiment, differential thermal analysis (DTA) was performed simultaneously. After this test, cyclic oxidation expermients was carried out at 800°C for 500 h. In as-cast state, Ce segregates to interdendritic areas and forms intermetallic phases. The effect connected with melting of interdendritic precipitates was observed at 1160°C. Ce-containing alloys were less prone of oxide spallation. Moreover, oxidation rate of these alloys substantially decreased after 100h of oxidation, whereas mass of the sample corresponding to base alloy continued to increase.

8

Wzbogacenie w REE utworów osadowych w wybranych rejonach obrzeżenia mezozoicznego Gór Świętokrzyskich : obiecujące dane wstępne i potrzeba dalszych badań

Mikulski Stanisław Z., Brański Paweł, Pieńkowski Grzegorz, Małek Rafał, Zglinicki Karol, Chmielewski Andrzej

Przegląd Geologiczny

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2021

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Vol. 69, nr 6

379--385

EN

The main task of research was a quantitative and qualitative identification of rare earth elements within various Mesozoic sediments in the surroundings of the Holy Cross Mountains. Over 100 samples from archive boreholes, outcrops and mining waste were analysed using modern methods, like portable XRF, geochemical analysis (ICP-MS), electron microprobe and SEM. Results show enrichments of REE concentrations in sedimentary rock samples from the Niektań PIG-1 borehole (LREE up to 0.95%), Miedary outcrop (LREY up to 0.4%) and Lower Cretaceous phosphorites from mining waste in Chałupki and Annopol (LREE ~0.2%). Further investigation is strongly recommended in order to explain the distribution of REE in the study areas.

9

High-temperature carbothermal dephosphorization of Malaysian monazite

Udayakumar Sanjith, Sheikh Abdul Hamid Sheikh Abdul Rezan, Baharun Norlia, Pownceby Mark

Physicochemical Problems of Mineral Processing

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2021

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Vol. 57, iss. 6

140--155

EN

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.

10

Life Cycle Inventory (LCI) Stochastic Approach Used for Rare Earth Elements (REEs), Considering Uncertainty

Sala Dariusz, Bieda Bogusław

Inżynieria Mineralna

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2021

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no. 2

283--291

EN

The purpose of the paper is to present the results of the stochastic modelling with uncertainty performed with the use of Monte Carlo (MC) simulation with 10,000 cycles and a confidence interval of 95 %, as recommended. Analysed REEs were fitted by lognormal distributions by using the Crystal Ball® (CB) spreadsheet-based software after defining the geometric mean value (μg) and the standard deviation (σg), automatically calculated (matches) the lower, as well as, upper boundaries of lognormal distribution. The number of replications of a simulation affects the quality of the results. The principal output report provided by CB and presented in this study consists of the graphical representation in the form of the frequency chart, percentiles summary, and statistics summary. Additional CB options provide a sensitivity analysis with tornado diagrams. The data that was used for MC simulation of the LCI model includes available and published data concerning associated with the REEs. This paper discusses the results and show that the adopted approach is applicable for any REEs used in the LCI studies under uncertainty. The results obtained from this study can be used as the first step in performing a full LCA analysis and help practitioners as well as decision-makers in the environmental engineering and management.

11

Chemical and morphological characterization of polymetallic (Mn-Fe) nodules from the Clarion-Clipperton Zone in the Pacific Ocean

Kozłowska-Roman Agata, Mikulski Stanisław

Geological Quarterly

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2021

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Vol. 65, No. 4

art. no. 57

EN

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.

12

Mechanical alloying of Mg-Zn-Ca-Er alloy

Hrapkowicz Bartłomiej, Lesz Sabina, Kremzer Marek, Karolus Małgorzata, Pakieła Wojciech

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2021

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Vol. 69, nr 5

art. no. e137587

EN

Magnesium-based materials constitute promising alternatives for medical applications, due to their characteristics, such as good mechanical and biological properties. This opens many possibilities for biodegradable materials to be used as less-invasive options for treatment. Degradation is prompted by their chemical composition and microstructure. Both those aspects can be finely adjusted by means of proper manufacturing processes, such as mechanical alloying (MA). Furthermore, MA allows for alloying elements that would normally be really hard to mix due to their very different properties. Magnesium usually needs various alloying elements, which can further increase its characteristics. Alloying magnesium with rare earth elements is considered to greatly improve the aforementioned properties. Due to that fact, erbium was used as one of the alloying elements, alongside zinc and calcium, to obtain an Mg₆₄Zn₃₀Ca₄Er₁ alloy via mechanical alloying. The alloy was milled in the SPEX 8000 Dual Mixer/Mill high energy mill under an argon atmosphere for 8, 13, and 20 hours. It was assessed using X-ray diffraction, energy dispersive spectroscopy and granulometric analysis as well as by studying its hardness. The hardness values reached 232, 250, and 302 HV, respectively, which is closely related to their particle size. Average particle sizes were 15, 16, and 17 μm, respectively.

13

Lantanowce - metale krytyczne technologicznie. Dlaczego są tak istotne?

Arciszewska Żaneta, Godlewska-Żyłkiewicz Beata

Analityka : nauka i praktyka

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2021

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nr 2

41--46

PL

Szybki rozwój nowych technologii wykorzystujących lantanowce powoduje ogromny popyt na te metale. Istnieje więc konieczność zintensyfikowania poszukiwań zasobów pierwiastków ziem rzadkich oraz opracowania procedur opłacalnego ich odzyskiwania ze źródeł wtórnych.

14

Dolnokredowe fosforyty z NE obrzeżenia Gór Świętokrzyskichjako potencjalne źródło REE : badania wstępne

Zglinicki Karol, Szamałek Krzysztof, Salwa Sylwester, Górska Irena

Przegląd Geologiczny

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2020

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Vol. 68, nr 7

566--576

EN

The PGI-NRI conducts geological research on the documentation of occurrence of REE deposits in Poland. The deposit potential may be related to the formation of Lower Cretaceous phosphorites from the NE margin of the Holy Cross Mountains. Two phosphorite deposits were exploited in this region in the past: Chałupki (1936-1959) and Annopol (1952-1970). From the Chałupki old mine dump, 34 samples of fine-grained sand were collected. The pseudonodules were extracted from this sand. The sand from the dump is composed of quartz, francolite (carbonate-rich fluorapatite) Ca5(PO4,CO3)3F, illite and a small amount of feldspar, calcite and heavy minerals. The heavy fraction is composed of zircon, monazite and rutile. Sand has a low content of REE ranging from 47.56 to 185.26ppm. The phosphorite pseudonodules underwent a detailed mineralogical and chemical analysis. They are composed of francolite, quartz, illite, glauconite, feldspar and minor heavy minerals: zircon and monazite. For the first time, the whole spectrum of REE was analysed in pseudonodules. The I.REE content in the nodules ranges from 177.37 to 354.18ppm. This level of REE indicates a serious need for further exploration and research of phosphorite pseudonodules within the whole Lower Cretaceous phosphorite series and moreover, also in the Eocene phosphorite formation in the Lublin region.

15

Separation of rare earth elements from the leaching solution of waste phosphors by solvent extraction with Cyanex 272 and its mixture with Alamine 336

Xing Weidong, Lee Man Seung

Physicochemical Problems of Mineral Processing

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2020

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Vol. 56, iss. 1

184--194

EN

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.

16

Evaluation of alkali processing for the recycling of rare earth values from spent fluorescent lamps

Shukla Neha, Tanvar Himanshu, Dhawan Nikhil

Physicochemical Problems of Mineral Processing

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2020

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Vol. 56, iss. 4

710--722

EN

Phosphor samples collected after crushing and sieving of discarded fluorescent lamps comprise approximately 31 % rare earth elements in the form of Y1.90Eu0.10O3, Al11Ce0.67MgO19Tb0.33, and Al10.09Ba0.96Mg0.91O17: Eu2+ phase. Direct leaching and mechanical activation assisted leaching are incapable of recovering Ce, Tb values from the Al11Ce0.67MgO19Tb0.33 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 NaAlO2. 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.

17

Tests of neodymium content in selected materials

Friebe Paweł

Mining Machines

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2020

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no. 2

38--47

EN

Rare earth elements are recognized as Critical Raw Materials (CRMs) due to their wide range of applications in the glass, steel, chemical and electronic industries. Often rare earth elements are referred to as a single group, but in practice each element has individual technical applications. Therefore, the demand varies for each element. Demand for rare earth elements is likely to increase in the future due to use of NdFeB magnets, especially in vehicles with electric motors and wind turbines. This publication presents research results aimed at finding raw material or waste that can be used to obtain neodymium at economical profit. This publication presents tests aimed at an identification of the raw material from which neodymium can be obtained. Research began with an identification of materials that could potentially become an economically viable source of neodymium extraction. The following materials were selected: natural aggregates, fine-grained raw materials of magma origin as well as coal sludge and fine-grained waste after hard coal enrichment. These raw materials were subject to content analysis by mass spectrometry, with ionization in inductively compressed plasma (ICP-MS).

PL

Pierwiastki ziem rzadkich zostały uznane w ostatnich czasach jako surowce krytyczne ze względu na ich szeroki zakres zastosowań w przemysłach: szklarskim, stalowym, chemicznym i elektronice. Często pierwiastki ziem rzadkich łączone są w jedną grupę, jednakże w praktyce każdy pojedynczy pierwiastek posiada odrębne zastosowania, dlatego popyt na każdy pierwiastek jest inny. Prognozy wskazują na prawdopodobny wzrost zapotrzebowania na pierwiastki ziem rzadkich, co może być związane między innymi ze zwiększenia stosowania magnesów NdFeB, szczególnie w pojazdach hybrydowych i elektrycznych oraz turbinach wiatrowych. W niniejszej publikacji przedstawiono badania mające na celu zidentyfikowanie surowca, z którego będzie można pozyskać neodym. Badania rozpoczęto od wskazania materiałów, które potencjalnie mogą stać się ekonomicznie uzasadnionym źródłem pozyskiwania neodymu. Wytypowane zostały: kruszywa naturalne, drobnoziarniste surowce pochodzenia magmowego oraz muły węglowe i drobnoziarniste odpady po wzbogacaniu węgla kamiennego. Surowce te zostały poddane analizie zawartości neodymu metodą spektrometrii mas, z jonizacją w plazmie indukcyjnie sprężonej (ICP-MS)

18

Rare Earth Elements – a Novelty in Energy Security

Bielawski Radosław

Journal of Ecological Engineering

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2020

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Vol. 21, nr 4

134--149

EN

This study analyses the role of rare earth elements (REE) as critical resources for the energy security. This research presents the developments in the global REE extraction, i.e. the dominance of the Republic of China, which attempts to maintain and control its monopoly. The typical and novel uses of rare earth metals were presented in various applications, such as in advanced electronic and information technologies utilised in the aerospace and energy industries. Bearing in mind their vital importance to the manufacturing of high-tech products, the REE deposits are of strategic importance for the USA, the Republic of China and for the European Union. Striving to maintain the independence of raw materials, the USA is focused on the search for raw materials on its territory and furthermore on waiving the legal restrictions with respect to their extraction. China is primarily occupied with maintaining the monopoly and control over the global market of critical raw materials, including REE. The activities within the European Union concentrate on the exploration in search for the REE deposits in Europe and ensuring the continuity of supplies by maintaining good diplomatic relations with partners – the USA and Japan. In addition, extensive REE recycling initiatives are being undertaken in the EU. Further rare earth metals extraction is anticipated to extend to the outer space. However, developing the economically viable methods of extraction remains the major challenge faced by space mining, given that it requires establishing an expensive, permanent space infrastructure. What is more, mining and processing of rare earth metals raises serious environmental concerns, as it involves such hazards as radioactive products, toxic chemical compounds and waste generation. With respect to the environmental protection, this study also addresses the issues of REE substitutes and recycling. It is concluded that the environmental protection practices regarding the long-term extraction and use of REE (with a 2030 horizon) will bring substantial long-term financial benefits.

19

The Proposal of Tungsten Ores Processing in Rwanda

Uwayezu Leader Senga, Mijał Waldemar, Niedoba Tomasz

Inżynieria Mineralna

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2020

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no. 1, vol. 1

161--170

EN

Tungsten is one of the rare elements occurring in Earth. Its applicability and request for it causes that the production of this metal is very beneficial. One of the biggest deposits of this metal ores in the world is located in African country of Rwanda. Due to the lack of appropriate technology and lack of investments the current way of producing this valuable metal in this country causes that much of tungsten is wasted as well the production is slow and the results are not appropriate. That is why an attempt to propose an adequate processing way for this deposit was done and is presented in this paper. Authors performed several tests on the ore originating from Rwanda, including its mineralogical composition and tests performed by means of laboratory shaking table. The results are promising and the further tests, including other methods of beneficiation are planned, like second shaking table stage and flotation.

PL

Wolfram jest jednym z pierwiastków rzadkich występujących na Ziemi. Jego zastosowania oraz zapotrzebowanie świata na ten produkt powodują, że produkcja tego metalu jest bardzo opłacalna. Jedno z największych złóż rudy tego metalu na świecie jest zlokalizowane w afrykańskim państwie, jakim jest Rwanda. Ze względu na brak odpowiedniej technologii oraz brak inwestycji obecny sposób produkcji tego cennego metalu w tym państwie powoduje, że duża ilość wolframu jest tracona, produkcja jest powolna, a wyniki nie są satysfakcjonujące. Dlatego przeprowadzono próbę zaproponowania odpowiedniego sposobu przeróbki tego złoża, która została zaprezentowana w tym artykule. Autorzy wykonali dużo ilość testów przeprowadzonych na rudzie sprowadzonej z Rwandy, włączając w to jej skład mineralogiczny, jak również testy laboratoryjne wzbogacania na stole koncentracyjnym. Wyniki są obiecujące a dalsze testy, włączając w to także inne metody wzbogacania są planowane do przeprowadzenia, biorąc pod uwagę drugi etap wzbogacania na stole koncentracyjnym czy flotację.

20

Effect of Magnet Scrap Size on the Extraction Behavior of Heavy Rare Earth Elements by Liquid Metal Extraction

Nam Sun-Woo, Rasheed Mohammad Zarar, Park Sang-Min, Lee Sang-Hoon, Kim Do-Hyang, Kim Taek-Soo

Archives of Metallurgy and Materials

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2020

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Vol. 65, iss. 4

1273--1276

EN

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%.