scholarly journals Recovery and Enhanced Upgrading of Rare Earth Elements from Coal-Based Resources: Bioleaching and Precipitation

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 484
Author(s):  
Zongliang Zhang ◽  
Landon Allen ◽  
Prasenjit Podder ◽  
Michael L. Free ◽  
Prashant K. Sarswat
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Modern Society ◽  
Electrical Equipment ◽  
Metal Alloys ◽  
Coal Waste ◽  
Separation Processes ◽  
Visual Minteq ◽  
Oxidant Production ◽  
Alternative Resource

Rare earth elements (REEs) are of great importance to modern society and their reliable supply is a major concern of many industries that utilize them in metal alloys, semiconductors, electrical equipment, and defense equipment. REEs in the coal waste have been revealed to be an alternative resource for REEs production. In this study, the extraction, recovery, and upgrading of the REEs from coal waste has been realized with the bioleaching and precipitation processes. Reliable and sustainable acid and oxidant production from the oxidation of the pyrite with Acidithiobacillus ferrooxidans to generate acid for leaching were realized in this research. The acidified bioleaching solution was used to extract REEs from coal waste, with 13–14% yields for most REE elements (~72 h of leaching). However, recovery for longer duration tests was significant higher (varies from 40–60% for individual REEs). After extraction, precipitation and separation processes were designed with the aid of Visual Minteq calculations and modeling to concentrate the REEs. With the procedures designed in this research, a final REEs precipitate product containing 36.7% REEs was produced.

Redox-Copolymers for the Recovery of Rare-Earth Elements by Electrochemically-Regenerated Ion Exchange

2021 ◽  
Author(s):  
Haley R Vapnik ◽  
Johannes Elbert ◽  
Xiao Su
Keyword(s):  
Renewable Energy ◽  
Rare Earth ◽  
Ion Exchange ◽  
Rare Earth Elements ◽  
Essential Role ◽  
Electronic Devices ◽  
Modern Society ◽  
Renewable Energy Technologies ◽  
Energy Technologies ◽  
Critical Resources

Rare earth elements (REEs) play an essential role in our modern society, being critical resources for the growing electronic devices and renewable energy technologies. Efficient technologies for REE recovery and...

scholarly journals The Occurrence of Selected Radionuclides and Rare Earth Elements in Waste at the Mine Heap from the Polish Mining Group

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 504
Author(s):  
Danuta Smołka-Danielowska ◽  
Agata Walencik-Łata
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Mineralogical Composition ◽  
Hard Coal ◽  
Coal Waste ◽  
Radiological Hazards ◽  
Study Results ◽  
Variable Distribution ◽  
Spectrometry Technique ◽  
Variable Content

The paper presents the results of research on rare earth elements (REY) and selected radionuclides in barren rocks deposited on a heap at a mine belonging to the Polish Mining Group (the largest producer of hard coal in EU countries). The maximum concentration of REEs determined in silstones was 261.6 mg/kg and in sandstones 221.2 mg/kg. The average uranium and thorium content in silstones was 6.8 mg/kg and 11.6 mg/kg, respectively. On the other hand, the samples of burnt coal shales contain on average 3.5 mg/kg of uranium and 9.7 mg/kg of thorium. In all coal waste samples, the REE values are higher than in hard coal (15.7 mg/kg). Carriers of REY, uranium, and thorium in coal waste are detritic minerals: monazite and xenotime, which are part of the grain skeleton of barren rocks. Coal waste samples are characterized by a variable distribution of REY concentrations as well as a variable content of radionuclides. The 226Ra, 228Ra, and 40K measurements in the investigated samples were performed using the gamma spectrometry technique. The concentrations of the analyzed isotopes differed depending on the mineralogical composition of the investigated samples. The present study results may be important in determining the possibility of utilization of wastes of barren rocks stored in the mine heap and in assessing environmental and radiological hazards.

scholarly journals Changes in the Concentration of Some Rare Earth Elements in Coal Waste

2017 ◽  
Vol 62 (3) ◽  
pp. 495-507
Author(s):  
Jacek Nowak ◽  
Magdalena Kokowska-Pawłowska
Keyword(s):  
Trace Elements ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Clay Minerals ◽  
Chemical Constituents ◽  
Thermal Transformation ◽  
Contact Metamorphism ◽  
Coal Waste ◽  
Coal Seams ◽  
Phase And Chemical Composition

AbstractCoal waste is formed during coal mining and processing operations. That waste comprises mainly sedimentary rocks that occur in roofs and floors of underground workings and in partings in coal seams. It contains numerous trace elements, including rare earth elements (REEs). Hypergenic processes that take place in coal waste piles may lead to endogenous fires. Thermal transformations of waste have an effect on changes in its phase and chemical composition, including the concentration of trace elements.The paper presents changes in the content of selected rare earth elements (Sc, Y, La, Ce, Nd, Sm, Eu, Tb, Yb, Lu) in wastes of varying degree of thermal transformation. The results of REE content determination in lump samples were subjected to statistical analysis and coefficients of correlation between the studied rare earth elements and the main chemical constituents were determined.The primary carriers of REEs in coal waste are clay minerals. Phase transformations that take place at high temperatures (including dehydroxylation of clay minerals and formation of minerals characteristic of contact metamorphism) cause changes in the concentration of rare earth elements.

scholarly journals Development of Rare Earth Elements Separation Processes from Coal Fly Ash

2021 ◽  
Vol 5 (1) ◽  
pp. 69
Author(s):  
Aggelos Tsachouridis ◽  
Francis Pavloudakis ◽  
Nikolas Kiratzis
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Coal Fly Ash ◽  
Thermal Power ◽  
Bottom Ash ◽  
Present Contribution ◽  
Separation Processes ◽  
Industry Studies ◽  
Global Industry ◽  
Wide Range

Rare Earth Elements and Yttrium (REY) constitute an important family of metals, with a wide range of applications and a massive impact on global industry. Studies have verified that the REY exist at significant concentrations in coal fly (CFA) and bottom ash (CBA). In the present contribution, the feasibility of CFA and CBA from the thermal power plant of PPC Meliti, Florina as a possible REY source is examined. Results are presented on the chemical and mineralogical analysis of the samples along with characterization of the initial material. Size separation results are also presented, as the first step in a subsequent beneficiation process for potential REY recovery.

scholarly journals The Market For The "Not-So-Rare" Rare Earth Elements

2012 ◽  
Vol 1 (1) ◽  
pp. 11-18 ◽  
Author(s):  
Joseph A. Giacalone
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Raw Materials ◽  
Rare Earth Metals ◽  
High Technology ◽  
Consumer Products ◽  
Separation Processes ◽  
Technology Products ◽  
Development Costs ◽  
The Rare Earth

This paper examines the market for the Rare earth elements. These are comprised of 17 elements of the periodic table which include 15 elements from the group known as lanthanides and two additional elements known as scandium and yttrium. The metals are often found combined together in ores and must be separated into its individual elements. The fact is that rare earth metals are not rare in terms of the quantity present in the earths crust. However, the metals are less concentrated than other more common metals and the extraction and separation processes necessitate high research and development costs and large capital outlays.The various applications of rare earth elements can be broadly classified into four major categories, namely: High Technology Consumer Products, Environmentally Friendly Products, Industrial and Medical Devices, and National Defense Systems. The demand for such high technology products is rapidly increasing causing a simultaneous upsurge in the demand for rare earth metals as well.On the supply side, China dominates the production rare earth elements, mining approximately 97% of total world production. Consequently, most countries must rely on imports of these REEs to facilitate production of the various systems and products that are dependent on the rare earth metals as raw materials. This near-monopoly imposes several supply-chain risks on the importing nations which are exploring ways to mitigate the potential economic harm associated with these risks.

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