Solvent Extraction of Gd from Chloride Solution with PC88A

Lee, Man Seung; Lee, Gwang-Seop; Lee, Jin Young; Kim, Sung-Don; Ahn, Jae-Woo; Kim, Joon-Soo

doi:10.2320/matertrans.46.259

Cited by 4 publications

(3 citation statements)

References 3 publications

(5 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The chemistry of cation exchange ligands for REE SX has been thoroughly investigated and is well-published; equilibrium behavior is highly dependent on REE concentrations and aqueous phase pH. − Although the chemistry is well understood, predicting partitioning behavior throughout a countercurrent SX circuit with complex extraction, scrubbing, and stripping cascades remains a significant challenge. Many SX separation models only predict the steady-state concentration profiles in the organic and aqueous phases across the cascade. ,, Furthermore, REE SX models utilize empirical correlations to predict extraction behavior but do not consider more complex multicomponent scrubbing equilibrium in REE separations, particularly for adjacent REE separations. ,− Scrubbing equilibria using cation exchange ligands becomes complex due to acid–metal exchange, metal–metal exchange, and equilibrium dependencies on REE concentrations, acid concentrations, and ligand concentrations. Transient SX behavior is expected to play a significant role for troubleshooting process upsets and fluctuations from upstream ore processing as well as managing startup and the approach to steady state due to impacts on process throughput, product purities, and production schedules.…”

Section: Introductionmentioning

confidence: 99%

Dynamic Modeling for the Separation of Rare Earth Elements Using Solvent Extraction: Predicting Separation Performance Using Laboratory Equilibrium Data

Lyon

Utgikar

Greenhalgh

2017

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

Industrial rare earth element (REE) separation facilities utilize acidic cation exchange ligands such as 2ethylhexylphosphonic acid mono-2-ethylhexyl ester (PC88A) for solvent extraction processes. REE separations are costly and difficult due to their chemical similarities and subsequent low separation factors. Several empirical correlations are available in the literature to predict steady state extraction equilibria for various solvent systems. However, complete solvent extraction flow sheet design for REE separations requires complex scrubbing and stripping circuits to separate and produce individual pure species. Furthermore, dynamic modeling of extraction, scrubbing, and stripping in REE separations circuits will aid in process design, optimization, and management of process fluctuations. A dynamic MATLAB/SIMULINK REE equilibrium model has been coupled with dynamic acid balances to predict REE solvent extraction processes using laboratory equilibrium data. The model was used to predict a flow sheet that produced high purity neodymium from a 25 wt % praseodymium and 75 wt % neodymium feed. Laboratory mixer−settlers were used to verify and validate model performance.Results indicated that the model reasonably predicts the dynamic behavior of a countercurrent REE separation process, and accurately predicts the steady state REE concentration profiles across the cascade. Transient concentration predictions exhibit more deviation from experimental results due to the initial assumption of a homogeneous, well-mixed stage. The model was revised to account for variations in mixer−settler holdup volumes for future validation efforts. Current model limitations assume complete equilibrium is achieved in each stage. The model can be applied to any REE separation or solvent system provided adequate laboratory equilibrium data are available.

show abstract

Section: Introductionmentioning

confidence: 99%

Dynamic Modeling for the Separation of Rare Earth Elements Using Solvent Extraction: Predicting Separation Performance Using Laboratory Equilibrium Data

Lyon

Utgikar

Greenhalgh

2017

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

show abstract

“…This interest in structural applications has motivated investigation of amorphous metals as alternatives to conventional crystalline metals in foam architectures, on account of their high-strength (typically around 2 GPa in compression [3], though amorphous alloys having compressive strengths above 5 GPa have been reported [4]), corrosion resistance, and processability (low liquidus temperatures in comparison to crystalline metals of similar strength, and high viscosity allowing foaming in the supercooled liquid state [5,6]). In order for amorphous metal foams to be viable alternatives to crystalline metal foams, however, it is necessary for them to exhibit compressive ductility far in excess of monolithic amorphous metals, which are typically limited to less than 1% compressive plastic strain in the absence of geometric confinement [7], ductile reinforcement [8], or anomalouslyhigh Poisson's ratios [9]. At low to intermediate porosities (!…”

Section: Introductionmentioning

confidence: 99%

Acoustic emissions analysis of damage in amorphous and crystalline metal foams

Prine

Dunand

2006

Intermetallics

View full text Add to dashboard Cite

“…It was reported that fine crystalline particles whose size and composition are similar to those of the A2 specimen were often formed during casting of the Vit-1 alloy, and that they were identified to be fcc phase (a ϭ 1.185 nm) according to transmission electron microscopy analysis. [13,14] It is likely that the fine crystalline particles in the A2 specimen are the same ones generally formed in the cast Vit-1 alloy. The presence of crystalline particles is confirmed by the X-ray diffraction data presented in Figures 5(a) and (b).…”

mentioning

confidence: 96%

Two-layered Zr-base amorphous alloy/metal surface composites fabricated by high-energy electron-beam irradiation

Lee

Yun

Lee

et al. 2004

Metall Mater Trans A

View full text Add to dashboard Cite

RECENTLY, remarkable advances in amorphous alloys have been made because of the development of amorphous alloys having substantially high glass forming ability by conventional casting methods. [1][2][3][4] Among them, Zr-base amorphous alloys show superb glass forming ability [5] (critical cooling rate: about 1°C/s, maximum sample diameter: over 30 mm), excellent hardness, stiffness, strength, and corrosion resistance, [4,6] and thus have been applied to components of sporting goods and electrical products. However, they have poor ductility and toughness because brittle fracture readily occurs due to the formation of localized shear bands under tensile or compressive stress, [7] and have difficulties of fabrication of large structures or components, thereby limiting wide applications to advanced structural materials. Thus, if the fabrication of amorphous alloy/metal surface composites, in which the surface region consists of an amorphous alloy and the interior substrate consists of a ductile metal having sufficient ductility and fracture toughness, can be newly developed, the aforementioned problems of amorphous alloys can be solved while fully taking advantage of amorphous alloys. As a promising method to fabricate these amorphous alloy/metal surface composites, direct irradiation of highenergy electron beam is suggested.Upon irradiation on the metal substrate surface with highenergy electron beam, high kinetic energy of electrons, being struck into material lattices and forming phonons, is transformed to high thermal energy, which can easily melt alloys or ceramics with high melting points. When high-energy electron beam is irradiated on a metal substrate, where amorphous powders are evenly deposited, the substrate surface and amorphous powders are completely melted and solidified to form an amorphous alloy layer, thereby fabricating amorphous alloy/metal surface composites. This high-energy electron-beam irradiation has several advantages: (1) strong interfacial bonding between surface composite layer and substrate, (2) prevention of surface oxidation and intrusion of inclusions because of short irradiation time, (3) prevention of pores or cracks because of homogeneous heating and cooling, and (4) possible continuous processing of large-scale structures or parts because of working in air. [8] Compared with the laser beam method, this method has twice higher thermal efficiency, and produces a thicker surface composite layer of several millimeters in thickness.In this study, an amorphous alloy/copper surface composite was fabricated by depositing Zr-base amorphous powders on a copper substrate and irradiating them with a high-energy electron beam. In order to thicken a surface composite layer and to obtain a homogeneous microstructure, a two-layered surface composite was fabricated by repeating the electronbeam irradiation process, and its microstructure and hardness were analyzed in comparison with those of the one-layered surface composite fabricated by the one-time electron-beam irradiation.The Zr-base amorph...

show abstract

Solvent Extraction of Gd from Chloride Solution with PC88A

Cited by 4 publications

References 3 publications

Dynamic Modeling for the Separation of Rare Earth Elements Using Solvent Extraction: Predicting Separation Performance Using Laboratory Equilibrium Data

Dynamic Modeling for the Separation of Rare Earth Elements Using Solvent Extraction: Predicting Separation Performance Using Laboratory Equilibrium Data

Acoustic emissions analysis of damage in amorphous and crystalline metal foams

Two-layered Zr-base amorphous alloy/metal surface composites fabricated by high-energy electron-beam irradiation

Contact Info

Product

Resources

About