Leaching of rare Earth elements from an Illinois basin coal source

Yang, Xinbo; Werner, Joshua; Honaker, R.Q.

doi:10.1016/j.jre.2018.07.003

Cited by 71 publications

(42 citation statements)

References 22 publications

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“…Given the low recovery and subsequent high production costs associated with physical beneficiation, direct chemical extraction of REEs from coal refuse has been evaluated by a number of researchers [11,20,21,25,[41][42][43]. Moreover, thermal and alkaline treatments prior to acid leaching have also been used to improve the REE leachability [21,[44][45][46][47].…”

Section: Chemical Extractionmentioning

confidence: 99%

A Comprehensive Review of Rare Earth Elements Recovery from Coal-Related Materials

et al. 2020

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Many studies have been published in recent years focusing on the recovery of rare earth elements (REEs) from coal-related materials, including coal, coal refuse, coal mine drainage, and coal combustion byproducts particularly fly ash. The scientific basis and technology development have been supported by coal geologists and extractive metallurgists, and through these efforts, the concept has progressed from feasibility assessment to pilot-scale production over the last five years. Physical beneficiation, acid leaching, ion-exchange leaching, bio-leaching, thermal treatment, alkali treatment, solvent extraction, and other recovery technologies have been evaluated with varying degrees of success depending on the feedstock properties. In general, physical beneficiation can be a suitable low-cost option for preliminary upgrading; however, most studies showed exceedingly low recovery values unless ultrafine grinding was first performed. This finding is largely attributed to the combination of small RE-bearing mineral particle size and complex REE mineralogy in coal-based resources. Alternatively, direct chemical extraction by acid was able to produce moderate recovery values, and the inclusion of leaching additives, alkaline pretreatment, and/or thermal pretreatment considerably improved the process performance. The studies reviewed in this article revealed two major pilot plants where these processes have been successfully deployed along with suitable solution purification technologies to continuously produce high-grade mixed rare earth products (as high as +95%) from coal-based resources. This article presents a systematic review of the recovery methods, testing outcomes, and separation mechanisms that are involved in REE extraction from coal-related materials. The most recent findings regarding the modes of occurrence of REEs in coal-related materials are also included.

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Section: Chemical Extractionmentioning

confidence: 99%

A Comprehensive Review of Rare Earth Elements Recovery from Coal-Related Materials

et al. 2020

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“…The activation energy values for both leaching periods were close to the energy barrier that is typically used to identify a diffusion controlled or chemical reaction controlled process, which is around 20 kJ/mol [26]. into different forms (i.e., ion exchange form, carbonate form, metal oxide form, acid soluble form, and insoluble form) with different levels of activation energy needed for extraction [24]. Zhang and Honaker (2020) studied the REE mode of occurrence in coal using the sequential chemical extraction method and quantified the REEs associated with each mode [30].…”

Section: Kinetic Analysismentioning

confidence: 60%

“…The remaining un-leached portion of Sc is likely associated with a mineral structure that requires a higher level energy to break down. Yang et al (2018) improved the scandium leaching recovery from 31% to 74% after treated by roasting with no chemical additives at 750 °C for 2 h from a coal-based material [24]. The effect of acid concentration on individual RE leaching recovery is shown in Figure 9.…”

Section: Effect Of Acid Concentrationmentioning

confidence: 99%

“…A possible explanation is that, due to the different modes of occurrence of REEs in coal-based material, the easy-to-leach REEs was instantaneously released at the beginning of the leaching process, and the hard-to-leach fraction controlled the reaction rate. The mode of occurrence of REEs can be categorized into different forms (i.e., ion exchange form, carbonate form, metal oxide form, acid soluble form, and insoluble form) with different levels of activation energy needed for extraction [24]. Zhang and Honaker (2020) studied the REE mode of occurrence in coal using the sequential chemical extraction method and quantified the REEs associated with each mode [30].…”

Section: Kinetic Analysismentioning

confidence: 99%

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Leaching Kinetics of Rare Earth Elements from Fire Clay Seam Coal

Yang

Honaker

2020

Minerals

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Recovery of rare earth elements (REEs) from coal samples collected from the Fire Clay coal seam using diluted mineral acid solutions was investigated. The initial processing step was coal recovery using conventional froth flotation which concentrated the REEs in tailing material resulting in an upgrade to values around 700 ppm on a dry whole mass basis. Leaching experiments were performed on the flotation tailings material using a 1.2 M sulfuric acid solution adjusted to a temperature of 75 °C to study the extractability of REEs from coal material. The effect of particle size, leaching time, leaching temperature, and solid concentration on REE leaching recovery were evaluated. The kinetic data obtained from leaching over a range of temperatures suggested that the leaching process follows the shrinking core model with possibly a mixed control mechanism that may be a result of several heterogenous materials leaching simultaneously. Leaching recovery increased rapidly at the beginning of the reaction then slowed as the system reached equilibrium. The apparent activation energy determined from test data obtained over a range of temperatures using 1 M sulfuric acid was 36 kJ/mol for the first 20 min of reaction time and 27 kJ/mol for the leaching period between 20 and 120 min. The leaching of light REEs during the initial stage was determined to be driven by a chemical reaction, followed by the formation of a product layer, which required lower activation energy in the later stage of leaching. In regards to the heavy REEs, the major mechanism for leaching is desorption and the product layer formation does not affect the heavy REEs significantly.

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“…, providing measurement of the lanthanide content of the leachate throughout consecutive processing cycles. Furthermore, chemicals employed in this electrophoretic system, such as ammonium and acetate , are present in the leaching processes of some environmental samples. This may provide opportunities for ITP in which a sample component, as compared to a separate electrolyte, provides the leading or terminating ion in the system .…”

Section: Resultsmentioning

confidence: 99%

Design and optimization of a fused‐silica microfluidic device for separation of trivalent lanthanides by isotachophoresis

et al. 2019

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DOI: https://doi.org/10.1002/elps.201900027 This cover picture shows the elemental separation of critical materials (rare earths) within a microfluidic channel using embedded electrodes. The embedded electrodes allow for fast manipulation of voltages in microfluidic channel. Electrophoresis is a powerful and green route to separating these chemically similar species and enabling fast, accurate analysis of the chemical species to further sourcing and processing options for these economically essential elements.

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Leaching of rare Earth elements from an Illinois basin coal source

Cited by 71 publications

References 22 publications

A Comprehensive Review of Rare Earth Elements Recovery from Coal-Related Materials

A Comprehensive Review of Rare Earth Elements Recovery from Coal-Related Materials

Leaching Kinetics of Rare Earth Elements from Fire Clay Seam Coal

Design and optimization of a fused‐silica microfluidic device for separation of trivalent lanthanides by isotachophoresis

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