scholarly journals Selective Leaching of Rare Earth Elements (REEs) from Eudialyte Concentrate after Sulfation and Thermal Decomposition of Non-REE Sulfates

Minerals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 522 ◽  
Author(s):  
Balinski ◽  
Atanasova ◽  
Wiche ◽  
Kelly ◽  
Reuter ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Produced Water ◽  
Ph Value ◽  
Selective Extraction ◽  
Water Leaching ◽  
Niobium Aluminum ◽  
Roasting Temperature ◽  
Eudialyte Concentrate ◽  
Roasting Time

Eudialyte, a sodium rich zirconosilicate, is one of the promising sources for REEs (rare earth elements), particularly for HREEs + Y (heavy rare earth elements and yttrium). The key challenge in hydrometallurgical processing is the prevention of silica gel formation and REE separation from resulting multi-element leach solutions. This study deals with the selective extraction of REE from eudialyte concentrate by selective roasting. In this method, metal ions are converted into sulfates, followed by the decomposition of non-REE sulfates in a roasting step and the water leaching of the calcine. The effect of acid addition, roasting temperature, roasting time, pulp density and leaching time is studied. For sufficient conversion of REEs into sulfates, sulfuric acid is added in excess. At a roasting temperature of ≥750 °C sulfates of zirconium, hafnium, niobium, aluminum and iron decompose into sparingly soluble compounds, while REE and manganese sulfates remain stable up to a roasting time of 120 min. The silica present in the calcine is found to be metastable even after roasting. The amount of leached Si4+ is dependent predominantly on the pH value of the leaching medium. Applying the method, REEs can be efficiently separated from zirconium, hafnium, niobium, aluminum and iron. However, only diluted solutions can be produced. Water leaching of calcine at high solid/liquid ratios causes REE losses resulting from formation of double sulfates and gypsum. The acid excess removed from the reaction mixture in the roasting stage can be simply recovered by treatment of the gas phase.

scholarly journals Water–rock interaction and the concentrations of major, trace, and rare earth elements in hydrocarbon-associated produced waters of the United States

2021 ◽  
Author(s):  
Carleton R. Bern ◽  
Justin E. Birdwell ◽  
Aaron M. Jubb
Keyword(s):  
United States ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Water Chemistry ◽  
Produced Water ◽  
The United States ◽  
Rock Interaction ◽  
Produced Waters ◽  
Water Rock Interaction

Comparisons of hydrocarbon-produced waters from multiple basins and experiments using multiple shales illustrate water–rock interaction influence on produced water chemistry.

Selective Extraction of Thorium from Rare Earth Elements Using Wrinkled Mesoporous Carbon

2018 ◽  
Vol 140 (44) ◽  
pp. 14735-14739 ◽  
Author(s):  
Zijie Wang ◽  
Alexander T. Brown ◽  
Kui Tan ◽  
Yves J. Chabal ◽  
Kenneth J. Balkus
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Mesoporous Carbon ◽  
Selective Extraction

scholarly journals Selective Roasting of Nd–Fe‒B Permanent Magnets as a Pretreatment Step for Intensified Leaching with an Ionic Liquid

2019 ◽  
Vol 6 (1) ◽  
pp. 91-102 ◽  
Author(s):  
Martina Orefice ◽  
Amy Van den Bulck ◽  
Bart Blanpain ◽  
Koen Binnemans
Keyword(s):  
Ionic Liquid ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Permanent Magnets ◽  
Metallic Phase ◽  
Process Step ◽  
Mechanical Removal ◽  
Oxidative Roasting ◽  
Roasting Temperature ◽  
The Rare Earth

AbstractOxidative roasting of Nd–Fe‒B permanent magnets prior to leaching improves the selectivity in the recovery of rare-earth elements over iron. However, the dissolution rate of oxidatively roasted Nd–Fe‒B permanent magnets in acidic solutions is very slow, often longer than 24 h. Upon roasting in air at temperatures above 500 °C, the neodymium metal is not converted to Nd2O3, but rather to the ternary NdFeO3 phase. NdFeO3 is much more difficult to dissolve than Nd2O3. In this work, the formation of NdFeO3 was avoided by roasting Nd–Fe‒B permanent magnet production scrap in argon atmosphere, having an oxygen content of $$ p_{{{\text{O}}_{2} }} \, \le \,10^{ - 20} \;{\text{atm}}, $$pO2≤10-20atm, with the addition of 5 wt% of carbon as an iron reducing agent. For all the non-oxidizing iron roasting conditions investigated, the iron in the Nd–Fe‒B scrap formed a cobalt-containing metallic phase, clearly distinct from the rare-earth phase at microscopic level. The thermal treatment was optimized to obtain a clear phase separation of metallic iron and rare-earth phase also at the macroscopic level, to enable easy mechanical removal of iron prior to the leaching step. The sample roasted at the optimum conditions (i.e., 5 wt% carbon, no flux, no quenching step, roasting temperature of 1400 °C and roasting time of 2 h) was leached in the water-containing ionic liquid betainium bis(trifluoromethylsulfonyl)imide, [Hbet][Tf2N]. A leaching time of only 20 min was sufficient to completely dissolve the rare-earth elements. The rare-earth elements/iron ratio in the leachate was about 50 times higher than the initial rare-earth elements/iron ratio in the Nd–Fe‒B scrap. Therefore, roasting in argon with addition of a small amount of carbon is an efficient process step to avoid the formation of NdFeO3 and to separate the rare-earth elements from the iron, resulting in selective leaching for the recovery of rare-earth elements from Nd–Fe‒B permanent magnets.

scholarly journals A biosorption-based approach for selective extraction of rare earth elements from coal byproducts

2020 ◽  
Vol 241 ◽  
pp. 116726 ◽  
Author(s):  
Dan Park ◽  
Andrew Middleton ◽  
Ryan Smith ◽  
Gauthier Deblonde ◽  
Dan Laudal ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Selective Extraction

scholarly journals Environmentally friendly comprehensive hydrometallurgical method development for neodymium recovery from mixed rare earth aqueous solutions using organo-phosphorus derivatives

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Verónica Cristina Arellano Ruiz ◽  
Rambabu Kuchi ◽  
Pankaj Kumar Parhi ◽  
Jin-Young Lee ◽  
Rajesh Kumar Jyothi
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Method Development ◽  
Neodymium Oxide ◽  
Selective Extraction ◽  
Extractant Concentration ◽  
Cyanex 272 ◽  
Extraction Behavior ◽  
Technology Applications ◽  
Hydrometallurgical Method

Abstract Rare earth elements (REEs) have obtained a greatest significant in human lives owing to their important roles in various high technology applications. The present method development was deal technology important REEs such as neodymium, terbium and dysprosium, selective extraction with possible separation and recovery studies, successfully. The chloride mediated mixed aqueous solution containing 1500 mg/L each of REEs such as Nd, Tb and Dy was subjected at selective separation of Nd from other associated REEs. Three organo-phosphorous based commercial extracting agents such as Cyanex 272, PC 88A and D2EHPA, were employed for the extraction, possible separation and recovery of rare earth elements. A comparative extraction behavior of all these three extractants as function of time, pH influence, extractant concentration, temperature and diluents were systematically investigated. The extraction tendency of organo-phosphorus reagents towards the extraction of either of the REEs follows of the sequence as: D2EHPA > PC 88A > Cyanex 272. The thermodynamic behavior of either of the extractants on liquid–liquid extraction processing of REEs was investigated and thermodynamic calculations were calculated and presented. Substantial recovery of neodymium oxalate followed by its calcined product as neodymium oxide was ascertained from XRD study and SEM–EDS analysis.

Leaching of rare earth elements from eudialyte concentrate by suppressing silica gel formation

2017 ◽  
Vol 108 ◽  
pp. 115-122 ◽  
Author(s):  
P. Davris ◽  
S. Stopic ◽  
E. Balomenos ◽  
D. Panias ◽  
I. Paspaliaris ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Silica Gel ◽  
Gel Formation ◽  
Eudialyte Concentrate

Effective Extraction of Vanadium and Chromium from High Chromium Content Vanadium Slag by Sodium Roasting and Water Leaching

2016 ◽  
Vol 863 ◽  
pp. 144-148 ◽  
Author(s):  
Ming Li ◽  
Liang Xiao ◽  
Jing Jing Liu ◽  
Zhi Xin Shi ◽  
Zi Bi Fu ◽  
...  
Keyword(s):  
Chromium Content ◽  
Leaching Rate ◽  
Vanadium Slag ◽  
Water Leaching ◽  
Sodium Salts ◽  
High Chromium ◽  
Effective Factor ◽  
Roasting Process ◽  
Roasting Temperature ◽  
Roasting Time

The extraction of vanadium and chromium from high chromium content vanadium slag by salt roasting and water leaching process has been investigated, which uses mixed sodium salts (Na2CO3 and NaOH) as additive agent in roasting process. The mineralogical morphology was prospected by TG-DSC, XRD, SEM and EDS. The oxidation of slag and transversion of V/Cr-containing phase and sodium salts have been discussed. It has been demonstrated that the presence of NaOH contributes to decompose spinel and olivine phases, which is beneficial to reduce the roasting temperature and elevate V, Cr leaching ratio. The roasting parameters have been studied as a function of roasting temperature, roasting time and ratio of alkali, in which the roasting temperature is the most effective factor on the leaching rate of vanadium and chromium. Under the optimum condition, the leaching rates of V and Cr reached 95.8% and 97.6%, respectively.

scholarly journals Selective Extraction of Rare Earth Elements from Permanent Magnet Scraps with Membrane Solvent Extraction

2015 ◽  
Vol 49 (16) ◽  
pp. 9452-9459 ◽  
Author(s):  
Daejin Kim ◽  
Lawrence E. Powell ◽  
Lætitia H. Delmau ◽  
Eric S. Peterson ◽  
Jim Herchenroeder ◽  
...  
Keyword(s):  
Rare Earth ◽  
Solvent Extraction ◽  
Rare Earth Elements ◽  
Permanent Magnet ◽  
Selective Extraction
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