scholarly journals Processes and Technologies for the Recycling of Spent Fluorescent Lamps

2014 ◽  
Vol 16 (3) ◽  
pp. 80-85 ◽  
Author(s):  
Wojciech Kujawski ◽  
Beata Pospiech
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Industrial Application ◽  
New Technologies ◽  
Rare Earth Metals ◽  
Fluorescent Lamps ◽  
Potential Source ◽  
Efficient Recovery

Abstract The growing industrial application of rare earth metals led to great interest in the new technologies for the recycling and recovery of REEs from diverse sources. This work reviews the various methods for the recycling of spent fluorescent lamps. The spent fluorescent lamps are potential source of important rare earth elements (REEs) such as: yttrium, terbium, europium, lanthanum and cerium. The characteristics of REEs properties and construction of typical fl uorescent lamps is described. The work compares also current technologies which can be utilized for an efficient recovery of REEs from phosphors powders coming from spent fluorescent lamps. The work is especially focused on the hydrometallurgical and pyrometallurgical processes. It was concluded that hydrometallurgical processes are especially useful for the recovery of REEs from spent fluorescent lamps. Moreover, the methods used for recycling of REEs are identical or very similar to those utilized for the raw ores processing.

scholarly journals Production of Porous Ceramic Materials from Spent Fluorescent Lamps

2021 ◽  
Vol 11 (13) ◽  
pp. 6056
Author(s):  
Egle Rosson ◽  
Acacio Rincón Rincón Romero ◽  
Denis Badocco ◽  
Federico Zorzi ◽  
Paolo Sgarbossa ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
High Speed ◽  
Porous Ceramic ◽  
Ceramic Materials ◽  
Porous Ceramics ◽  
Fluorescent Lamps ◽  
Naoh Solution ◽  
Commercial Glass ◽  
Triton X

Spent fluorescent lamps (SFL) are classified as hazardous materials in the European Waste Catalogue, which includes residues from various hi-tech devices. The most common end-of-life treatment of SFL consists in the recovery of rare earth elements from the phosphor powders, with associated problems in the management of the glass residues, which are usually landfilled. This study involves the manufacturing of porous ceramics from both the coarse glass-rich fraction and the phosphor-enriched fraction of spent fluorescent lamps. These porous materials, realizing the immobilization of Rare Earth Elements (REEs) within a glass matrix, are suggested for application in buildings as thermal and acoustic insulators. The proposed process is characterized by: (i) alkaline activation (2.5 M or 1 M NaOH aqueous solution); (ii) pre-curing at 75 °C; (iii) the addition of a surfactant (Triton X-100) for foaming at high-speed stirring; (iv) curing at 45 °C; (v) viscous flow sintering at 700 °C. All the final porous ceramics present a limited metal leaching and, in particular, the coarse glass fraction activated with 2.5 M NaOH solution leads to materials comparable to commercial glass foams in terms of mechanical properties.

Polyethylenimine-cross-linked cellulose nanocrystals for highly efficient recovery of rare earth elements from water and a mechanism study

2017 ◽  
Vol 19 (20) ◽  
pp. 4816-4828 ◽  
Author(s):  
Feiping Zhao ◽  
Eveliina Repo ◽  
Yang Song ◽  
Dulin Yin ◽  
Samia Ben Hammouda ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Cellulose Nanocrystals ◽  
Chelating Agent ◽  
Mechanism Study ◽  
Highly Efficient ◽  
Cross Linker ◽  
Efficient Recovery

PEI acts not only as a cross-linker but also as a chelating agent for RE ions.

Leaching of Rare Earth Metals from Phosphor Coating of Waste Fluorescent Lamps

2018 ◽  
Vol 72 (3) ◽  
pp. 623-634 ◽  
Author(s):  
Amit Anand ◽  
Randhir Singh ◽  
Abdul Rauf Sheik ◽  
Malay Kumar Ghosh ◽  
Kali Sanjay
Keyword(s):  
Rare Earth ◽  
Rare Earth Metals ◽  
Fluorescent Lamps ◽  
Phosphor Coating

scholarly journals Rare Earth Occurrences in Streams of Processing a Phosphate Ore

Minerals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 262 ◽  
Author(s):  
Xiaosheng Yang ◽  
Hannu Tapani Makkonen ◽  
Lassi Pakkanen
Keyword(s):  
Rare Earth ◽  
Sulfuric Acid ◽  
Phosphoric Acid ◽  
Rare Earth Elements ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Phosphate Ore ◽  
Mineral Liberation ◽  
Efficient Recovery ◽  
Liberation Analysis

Rare earth elements (REEs) are defined as lanthanides with Y and Sc. Rare earth occurrences including the REE-bearing phases and their distributions, measured by rare earth oxides (REOs), in the streams of processing a phosphate ore were determined by using MLA, the mineral liberation analysis and EPMA, the electron probe microanalysis. The process includes an apatite ore beneficiation by flotation and further processing of the beneficiation concentrate with sulfuric acid. Twenty-six, sixty-two and twelve percent of the total REOs (TREO) contents from the ore end up in the products of beneficiation tailings, phosphogypsum (PG) and phosphoric acid, respectively. Apatite, allanite, monazite and pyrochlore are identified as REE-bearing minerals in the beneficiation process. In the beneficiation tailings, the REEs are mainly distributed in monazite (10.3% TREO), apatite (5.9% TREO), allanite (5.4% TREO) and pyrochlore (4.3% TREO). Gypsum, monazite, apatite and other REE-bearing phases were found to host REEs in the PG and the REEs distributions are 44.9% TREO in gypsum, 15.8% TREO in monazite, 0.6% TREO in apatite and 0.6% TREO in other REE-bearing phases. Perspectives on the efficient recovery of REEs from the beneficiation tailings and the PG are discussed.

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.

Secondary Resources of Rare Еarth Мetals

2020 ◽  
Vol 24 (9) ◽  
pp. 44-50
Author(s):  
S.A. Chernyi
Keyword(s):  
Rare Earth ◽  
Rare Earths ◽  
Industrial Waste ◽  
Rare Earth Metals ◽  
Nickel Metal ◽  
Nickel Metal Hydride ◽  
Processing Technologies ◽  
Apatite Concentrate ◽  
Fluorescent Lamps ◽  
High Processing

The article provides an overview of the main existing methods for recycling rare earth metals from various types of waste. It was noted that the demand for rare-earth metals is increasing annually due to the growth of advanced technologies, mainly in the sectors of electronics, power engineering and photonics. It has been established that in countries producing final products of high processing, the chemical-technological processes of processing goods that have worked out their life cycle, and, first of all, fluorescent lamps, NdFeB magnets from electronic devices, and nickel-metal hydride (NiMeH) batteries containing rare earths are most quickly created. The most profitable and recycling option is the reuse of products containing rare-earth metals, however, such technologies are applicable for a narrow range of waste. Another important area of REM recycling is the processing of industrial waste. For countries with developed mining and chemical industries, mining processing technologies are attractive. It is shown that for Russia, more appropriate are schemes for the disposal of industrial waste, primarily waste from the production of apatite concentrate. The main problems of the development of REM recycling are identified: low content and dispersion of rare earths in waste; the presence of impurities that impede the extraction of valuable components and the toxicity of the used recycling schemes.

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".

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