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
2020 ◽  
Vol 24 (9) ◽  
pp. 44-50
Author(s):  
S.A. Chernyi

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.


2014 ◽  
Vol 16 (3) ◽  
pp. 80-85 ◽  
Author(s):  
Wojciech Kujawski ◽  
Beata Pospiech

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.


Author(s):  
V. B. Baranovskaya ◽  
Yu. A. Karpov ◽  
K. V. Petrova ◽  
N. A. Korotkova

This review is devoted to the review of current trends in the use of rare-earth metals (REM) in two major scientific and technical fields – the production of magnetic and luminescent materials. The reviews show that it is REM that gives this product unique properties. The information on the content of matrix and alloying components, their influence on achieving the required characteristics of the most popular magnetic materials is systematized. The prospects of new combinations of rare-earth metals in the further progress of the production of magnetic materials for various purposes are shown. Along with the traditional cobalt-samarium and neodymium-iron-boron compositions, new magnetic materials with increased hysteresis properties and temperature-time stability have been developed, phases with variable valence have been synthesized, which are used as memory elements in information systems. The article also reviews and summarizes the results of studies in another important area of REM application – the creation of luminescent materials. Phosphors based on compounds of rare earth metals are used in the production of high-pressure mercury lamps with improved characteristics, X-ray screens, high and low pressure fluorescent lamps, screens for electron-optical converters. Narrow-band phosphors based on REM compounds are of interest for lamps used in plant growing, especially for areas with a cold climate, where year-round plant growth is possible only with the use of additional radiation sources.The trends in the synthesis of luminescent materials using various rare-earth metals and their combinations are revealed. Attention is turned to the need to use chemically pure precursors of rare-earth metals in the creation of such materials. The prospects of creating nanophosphors, as well as the improvement of synthesis methods and diagnostic methods, are noted.


2018 ◽  
Vol 56 (2C) ◽  
pp. 133-139
Author(s):  
Nguyen Duc Quang

Discarded fluorescent lamps were considered as hazardous waste in Vietnam (code is 160106). However, its composition contained valuable rare earth metals, which can be recycled and recovered by leaching and solvent extraction processes. The present study sought to define the conditions of separation for rare earth elementals (REEs) from acid leach solution by solvent extraction using PC88A. The acid leach solution was obtained from leaching of fluorescent powder. Efficiencies on REEs extractions as functions of pH levels, extractant concentration, O/A ratio, metal concentration were investigated. For pH values greater than 0.0 and less than 1.0, the orders of the yields extraction were determined: yttrium > terbium > europium > aluminum and calcium. The best separation circuit included four-stage counter current extraction for yttrium separation with 20 %v/v PC88A in kerosene (O/A = 1/1, room temperature, 20 min of contact, pH of 0.38) and stripping step with 3 M HCl acid (O/A = 1/1, room temperature, 30 min of contact). After yttrium separation, the leach solution was extracted at pH of 0.98 in the same other conditions with two-stage counter current extraction to recover terbium and europium group. The final recovery from leach liquor was higher than 98 % and the grade of the final product was 94.2 % (for yttrium) and 93.8 % (for terbium and europium group).


1979 ◽  
Vol 40 (C5) ◽  
pp. C5-260-C5-261 ◽  
Author(s):  
M. Müller ◽  
E. Huber ◽  
H.-J. Güntherodt

1980 ◽  
Vol 41 (C1) ◽  
pp. C1-25-C1-31 ◽  
Author(s):  
N. S. Dixon ◽  
L. S. Fritz ◽  
Y. Mahmud ◽  
B. B. Triplett ◽  
S. S. Hanna ◽  
...  

2015 ◽  
Vol 53 (9) ◽  
pp. 637-641
Author(s):  
Chul-Woo Nam ◽  
Kyung-Ho Park ◽  
Hyun-Ho Kim ◽  
Jin-Tae Park

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