scholarly journals The presence of rare earth elements and critical metals in waste electric and electronic equipment: challenges for recovery

2019 ◽  
Vol 20 (4) ◽  
pp. 773-777
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Scientific Community ◽  
Rare Earth Metals ◽  
Economic Importance ◽  
Electronic Equipment ◽  
Insufficient Data ◽  
Supply Risk ◽  
Critical Metals ◽  
Non Profit

<p>The fastest growing waste stream of waste electric and electronic equipment (WEEE) is not only a threat to our environment, but is also creating a supply risk of certain rare earth metals (REMs) and critical metals (CMs). Despite the fact that Directive 2012/19/EU encourages the prevention of WEEE by promoting re-use, recycling and other forms of recovery of such wastes, the recycling of these metals in WEEE is less than 1%. The insufficient data about the composition of REMs and CMs in electric and electronic equipment (EEE), the high recycling costs and the different motivations/interests of the stakeholders, including national authorities, non-profit companies and producers, are some of the main inhibitor factors. However, there is a growing interest in the scientific community in sorting out the issues which leads to such a low recovery and in defining the challenges and possible benefits generated from the recycling of REMs and CMs. On this basis, this work highlights the characteristics of REMs and CMs in terms of their economic importance and their presence in EEE. Then, an overview of the supply risk of REMs and CMs and the challenges related to the recovery are provided, supported by countries examples.</p>

Process optimization for acidic leaching of rare earth elements (REE) from waste electrical and electronic equipment (WEEE)

2021 ◽  
Author(s):  
Ayse Yuksekdag ◽  
Borte Kose-Mutlu ◽  
Bihter Zeytuncu-Gokoglu ◽  
Mustafa Kumral ◽  
Mark R. Wiesner ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Process Optimization ◽  
Electronic Equipment

scholarly journals Material efficiency: rare and critical metals

2013 ◽  
Vol 371 (1986) ◽  
pp. 20110563 ◽  
Author(s):  
Robert U. Ayres ◽  
Laura Talens Peiró
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Platinum Group Metals ◽  
Rare Metals ◽  
Critical Metals ◽  
The Past ◽  
Material Efficiency ◽  
Aluminium Copper ◽  
Copper Zinc ◽  
Industrial Metals

In the last few decades, progress in electronics, especially, has resulted in important new uses for a number of geologically rare metals, some of which were mere curiosities in the past. Most of them are not mined for their own sake (gold, the platinum group metals and the rare Earth elements are exceptions) but are found mainly in the ores of the major industrial metals, such as aluminium, copper, zinc and nickel. We call these major metals ‘attractors’ and the rare accompanying metals ‘hitch-hikers’. The key implication is that rising prices do not necessarily call forth greater output because that would normally require greater output of the attractor metal. We trace the geological relationships and the functional uses of these metals. Some of these metals appear to be irreplaceable in the sense that there are no known substitutes for them in their current functional uses. Recycling is going to be increasingly important, notwithstanding a number of barriers.

scholarly journals The economic importance of rare earth elements volatility forecasts

2020 ◽  
Vol 71 ◽  
pp. 101316 ◽  
Author(s):  
Juliane Proelss ◽  
Denis Schweizer ◽  
Volker Seiler
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Economic Importance

THERMODYNAMICS OF THE PROCESSES OF INTERACTION OF LIQUID METAL COMPONENTS IN Fe – Mg – Al – La – O SYSTEM

2018 ◽  
Vol 61 (6) ◽  
pp. 460-465
Author(s):  
G. G. Mikhailov ◽  
L. A. Makrovets ◽  
L. A. Smirnov
Keyword(s):  
Rare Earth ◽  
Liquid Metal ◽  
Rare Earth Elements ◽  
Phase Equilibria ◽  
Thermodynamic Modeling ◽  
Equilibrium Constants ◽  
Rare Earth Metals ◽  
Oxide Systems ◽  
Metal Melts ◽  
Steel Deoxidation

At the present time, rare-earth elements in metallurgy are used in  the form of mischmetal – a rare-earth elements natural mixture (with  atomic numbers from 57 to 71). It contains about 50  wt.  % of cerium.  The remaining elements are mainly lanthanum and niobium. The specific composition is determined by the ore deposit. Inconstant composition of the modifier containing rare-earth metals (REM) can significantly reduce its efficiency. Experimentally, for every branded steels  composition the ratio of various REMs can’t be selected because of the  high costs of obtaining technically pure rare-earth metals. The task of  determining the each rare earth element optimum concentrations and  complex ligature composition can be solved by thermodynamic modeling. In the framework of thermodynamic modeling, the interaction  between magnesium, aluminum and lanthanum with oxygen in liquid  iron is presented. And the thermodynamic model of steel deoxidation  by these active metals composition is considered. On the basis of available literature data on the phase diagrams of the systems MgO – Al2O3 ,  MgO – La2O3 and La2O3 – Al2O3 , the coordinates of the invariant equilibria points in the system MgO – La2O3 – Al2O3 were determined. The  phase diagram of the system MgO – La2O3 – Al2O3 was constructed. It  made possible to establish all phase equilibria realized in the process  of deoxidation of steel with magnesium, lanthanum and aluminum and  to describe these phase equilibria by chemical reactions equations. The  activity of the components in liquid oxide melts was determined using  the theory of subregular ionic solutions, which takes into account the  dependence of the coordination number of cations on the composition  of the oxide melt. The activity of components in metal melts conjugated with oxide systems were determined by Wagner’s theory using the  parameters of the first order interaction. Equilibrium constants values  for the steel deoxidation reactions are installed indirectly by thermodynamic calculations. On the basis of the obtained data the components  solubility surface in the metal melts of Fe – Mg – Al – La – O system  was constructed, which allowed to determine the liquid metal composition regions associated with the corresponding oxide phase.

scholarly journals An Overview of Rare Earth Ores Beneficiation in Vietnam

2021 ◽  
Vol 1 (2) ◽  
Author(s):  
Thi Kim Dung NHU ◽  
Van Luan PHAM ◽  
Thi Chinh VU ◽  
Van Duoc TRAN
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Magnetic Materials ◽  
Animal Feed ◽  
Rare Earth Metals ◽  
Earth’S Crust ◽  
Research Projects ◽  
Essential Minerals ◽  
Different Types ◽  
Earth's Crust

Rare earth metals are used in electricity, electronics, nuclear, optics, space, metallurgy,superconducting and super magnetic materials, glass and ceramics, and agriculture. Some rare earthelements are added to fertilizers for crops and some trials for animal feed. Rare earth elements, exceptfor radioactive promethium, are relatively abundant in the earth's crust. Vietnam has a tremendous rareearth potential, distributed mainly in the Northwest, including Nam Xe, Dong Pao, Muong Hum, andYen Bai. There are many research projects on rare earth ores of different types globally, but the focus ismainly on the essential minerals, including monazite, xenotime, and bastnaesite. This report summarizesresearch data on rare earth ore intending to produce a general assessment of rare earth ore and itsbeneficiation technology in Vietnam.

scholarly journals Physical Properties Of Rare Earth Elements

2021 ◽  
Vol 03 (01) ◽  
pp. 79-88
Author(s):  
Davron Rakhmonovich Djuraev ◽  
◽  
Mokhigul Madiyorovna Jamilova ◽  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Physical Properties ◽  
Phase Transformations ◽  
Rare Earth Metals ◽  
Economic Effect ◽  
Structure And Properties ◽  
Structure And Stability ◽  
Ongoing Phase

The article studies the physical properties of rare earth metals, pays special attention to their unique properties, studies the main aspects of the application of rare earth metals in industry. Also, the structure and stability of various forms of sesquioxides of rare earth elements, in particular, europium, as well as the effect of the method of oxide preparation on its structure and properties are considered. The analysis of the ongoing phase transformations of rare earth metals is made. The article emphasizes the use of correct choices to achieve a large technical and economic effect when using rare earth metals in industry. The article is intended for teachers working in the field of physics and chemistry, as well as for students of the specialty "physics and chemistry".

scholarly journals Peningkatan Perolehan Uranium, Torium, dan Logam Tanah Jarang dalam Residu Pelarutan Parsial pada Pengolahan Monasit

EKSPLORIUM ◽  
2021 ◽  
Vol 42 (2) ◽  
pp. 141
Author(s):  
Novita Sari Fatihah ◽  
Mutia Anggraini ◽  
Afiq Azfar Pratama ◽  
Kurnia Setiawan Widana
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Rare Earth Metals ◽  
Ammonium Hydroxide ◽  
Deposition Process ◽  
Optimum Process ◽  
Process Conditions ◽  
Radioactive Elements ◽  
Partial Dissolution ◽  
Total Dissolution

ABSTRAK. Monasit merupakan mineral hasil samping pengolahan timah yang mengandung fosfat, logam tanah jarang, dan unsur radioaktif berupa uranium dan torium. Unsur-unsur tersebut dapat dimanfaatkan secara optimal jika terpisah satu dengan yang lainnya melalui proses pengolahan. Pengolahan monasit meliputi proses dekomposisi, pelarutan parsial, dan pengendapan. Pemisahan unsur logam tanah jarang dari unsur radioaktif dalam monasit dilakukan melalui proses pelarutan parsial, akan tetapi pemisahan tersebut belum optimal sehingga diperlukan proses lebih lanjut untuk meningkatkan perolehan unsur-unsur tersebut. Pada penelitian ini, proses tersebut dilakukan melalui dua metode yaitu pelarutan total dengan asam klorida (HCl) yang bertujuan untuk melarutkan semua unsur dalam endapan dan pengendapan dengan ammonium hidroksida (NH4OH) yang bertujuan untuk memisahkan unsur radioaktif dan unsur logam tanah jarang. Kedua metode tersebut dilakukan pada kondisi optimum proses dengan berbagai variasi pH, suhu, dan waktu. Berdasarkan hasil pengamatan diperoleh bahwa kelarutan optimum masing-masing unsur sebesar 67,6% uranium, 15,3% torium, dan 50,8% LTJ pada kondisi proses pelarutan pH 1, pada suhu 80°C selama 2 jam. Sedangkan pada proses pengendapan diperoleh recovery pengendapan masing-masing unsur sebesar 57% uranium, 75,7% torium, 4,8% logam tanah jarang pada kondisi pH 6. Berdasarkan data tersebut disimpulkan bahwa uranium, torium, dan logam tanah jarang dapat larut pada kondisi proses pelarutan pH 1, suhu 80°C selama 2 jam, dan dapat dipisahkan pada kondisi pH pengendapan 6.ABSTRACT. Monazite is a by-product of tin processing containing phosphate, rare earth elements, and radioactive elements such as uranium and thorium. These elements can be utilized optimally if separated from one another through processing. Monazite processing includes decomposition, partial dissolution, and precipitation processes. The separation of rare earth elements from radioactive elements in monazite is carried out through a partial dissolution process, but the separation is not optimal so that further processes are needed to increase the recovery of these elements. In this study, the process was carried out using two methods, namely total dissolution with hydrochloric acid (HCl) which aims to dissolve all elements in the precipitate and precipitation with ammonium hydroxide (NH4OH) which aims to separate radioactive elements and rare earth elements. Both methods were carried out under optimum process conditions with various variations in pH, temperature, and time. Based on observations, it was found that the optimum solubility of each element was 67.6% uranium, 15.3% thorium and 50.8% LTJ under the dissolving process conditions of pH 1, at 80°C for 2 hours. While in the deposition process, the precipitation recovery of each element is 57% uranium, 75.7% thorium, 4.8% rare earth metals at pH 6 conditions. Based on these data, it can be concluded that uranium, thorium, and rare earth elements can be dissolved at pH 1, at 80°C for 2 hours, and can be separated at pH 6 precipitation conditions.

scholarly journals Study of rare earth elements in the coals of the Shubarkol deposit

2021 ◽  
Vol 4 (319) ◽  
pp. 48-56
Author(s):  
A. Amangeldykyzy ◽  
◽  
A. N. Kopobayeva ◽  
N. S. Askarova ◽  
D.S. Ozhigin ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Rare Earth Metals ◽  
Microscopic Analysis ◽  
Resource Base ◽  
Weathering Processes ◽  
Multiple Processes ◽  
Tenfold Excess ◽  
Coal Accumulation ◽  
Object Of Study

The work studies mineralogical and geochemical features of the Jurassic coals of the Shubarkol deposit. The samples were examined using the method of scanning electron microscopy (SEM-EDX) Hitachi S-3400N, which was carried out at the Uranium Geology Research and Development Center at the Department of Geoecology and Geochemistry of TPU. Coal geochemistry was studied by instrumental neutron activation analysis (INAA) at the nuclear geochemical laboratory of the Department of Geoecology and Geochemistry of National Research Tomsk Polytechnic University (TPU). The choice of this object of study was determined by the tasks of research including the study of the patterns of accumulation of abnormal concentrations of REE, the effect of various factors of the geological environment on the levels of their accumulation in coals, as well as the conditions of its concentration and forms of occurrence in coals to expand the mineral resource base of Kazakhstan for rare earth elements. According to the results of scanning microscopic analysis, aluminosilicates, sulfides and sulfates with inclusions of microparticles of rare and rare earth elements were found in the composition of the Shubarkol deposit coals. According to the INNA results, abnormal concentrations of Sc, Ta, Nb, Hf, Zr, Ba, Sr, Ce and REE were found. Weathering processes led mainly to the loss and redistribution of REE in the coal seams of the Shubarkol deposit, which in turn led to increasing the content of rare earth elements from the bottom up the section. As a result of the action of multiple processes, increased concentrations of rare earth metals, mainly of the yttrium group, were formed. The absence of negative europium anomaly was determined, which confirms the original rocks composition peculiarity. The maximum contents of rare-earth metals are confined to weathered coals; for the medium-heavy group (Nd, PM, Sm, Eu), they are almost a hundredfold higher than the clarke in the upper continental crust. The tenfold excess of the clarke for elements from Gd to Lu was found in clayey sandstones and siltstones; for the rest of the rocks of the deposit the excess over the clarke is significantly lower. It was found that the coals of the deposit belong to the H-type and L-type of REE distribution. During the formation of oxidized H-type coals, clayey matter of terrigenous ash predominated as a carrier of REE, while unoxidized L-type coals were formed with the introduction of REE into the coal accumulation basin mainly in the composition of clay minerals and LREE-phosphates. Here the main source of REE was apparently the weathering crust over acidic rocks.

Study on Recovery of Rare Earth Elements from NdFeB Magnet Scrap by Using Selective Leaching

2020 ◽  
Vol 1009 ◽  
pp. 149-154
Author(s):  
Tanongsak Yingnakorn ◽  
Piamsak Laokhen ◽  
Loeslakkhana Sriklang ◽  
Tapany Patcharawit ◽  
Sakhob Khumkoa
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Rare Earth Element ◽  
Earth Element ◽  
Rare Earth Metals ◽  
Hard Disk Drives ◽  
Selective Leaching ◽  
High Concentration ◽  
Neodymium Magnets ◽  
The Rare Earth

High power neodymium magnets have been used extensively, such as components of hard disk drives, electric vehicles, and maglev trains. This type of magnet contains of high concentration of rare earth elements. After the device is out of service, the magnet will be removed and the rare earth element contained in the magnet will be extracted in order to reuse for any purposes. Recently, the study on extraction of rare earth elements (REE) from neodymium magnets is increased. However, there was only few research regarding to the extraction of rare earth metals by using a water leaching method. In this study, rare-earth elements were extracted from neodymium magnet scrap by using selective leaching technique. Initially, magnets were leached with 2 M of sulfuric acid for 24 hrs. Then, the leached solution was heated at 110°C in order to remove water and the green powder was remained. The green powder was further roasted in a muffle furnace at various temperatures from 750°C to 900°C for 2 hrs. and subsequently leached by water. Finally, the iron oxide residue was separated from rare earth element solution by filtration. Based on this experiment, it was found that the purity of the rare earth metals can be achieved up to 99.4%.

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