Leaching behaviour of rare earth elements from low-grade weathered crust elution-deposited rare earth ore using magnesium sulfate

Clay Minerals ◽  
2018 ◽  
Vol 53 (3) ◽  
pp. 505-514
Author(s):  
Kaihua Chen ◽  
Jiannan Pei ◽  
Shaohua Yin ◽  
Shiwei Li ◽  
Jinhui Peng ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Magnesium Sulfate ◽  
Low Grade ◽  
Second Stage ◽  
Leaching Solution ◽  
Weathered Crust ◽  
Leaching Behaviour ◽  
N Pollution ◽  
Leaching Efficiency

ABSTRACTThe present study investigates the use of magnesium sulfate (MgSO4) instead of (NH4)2SO4 as a lixiviant in the recovery of rare earth elements (REEs) from clays. Experiments were carried out to investigate the influence of leaching conditions such as leaching time, lixiviant concentration and liquid:solid ratio on the leaching efficiency. The optimum leaching conditions, leading to 75.48% of total REE leaching efficiency, required a stirring speed of 500 rpm, a leaching time of 30 min, a lixiviant concentration of 3 wt.% and a liquid:solid ratio of 3:1. After extension of the leaching process by a second stage, the leaching efficiency may reach up to 96.19%, which is slightly higher than that obtained by (NH4)2SO4. Leaching varies from element to element, with Ce presenting the lowest leaching efficiency, and the partition in leaching solution is in agreement with that in raw ore other than for Ce. Based on these findings, MgSO4 lixiviant is an excellent alternative leaching agent for a sustainable REE industry because it reduces or eliminates NH4+–N pollution.

scholarly journals Allanite Geochemical Response to Hydrothermal Alteration by Alkaline, Low-Temperature Fluids

Minerals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 392 ◽  
Author(s):  
Katarzyna Gros ◽  
Ewa Słaby ◽  
Petras Jokubauskas ◽  
Jiří Sláma ◽  
Gabriela Kozub-Budzyń
Keyword(s):  
Rare Earth ◽  
Low Temperature ◽  
Rare Earth Elements ◽  
Geochemical Evolution ◽  
Additional Component ◽  
Second Stage ◽  
Ce Anomaly ◽  
Hydrothermal Processes ◽  
Fluid Infiltration ◽  
Two Stages

Allanite is one of the main rare earth elements (REE)-rich accessory minerals in composite dykes from the granitoid pluton of Karkonosze. These dykes differ in composition from the bulk of the pluton by elevated rare earth elements (REE), Y, Zr, and alkali contents, suggesting contribution of an additional component. Allanite exhibits complex alteration textures, which can be divided into two stages. The first stage is represented by allanite mantles, formed by fluid infiltration into previously crystallized magmatic allanite. These zones have low totals, are Ca-, Al-, Mg-, and light REE (LREE)-depleted, and Y-, heavy REE (HREE)-, Th-, Ti-, and alkali-enriched. The fractionation between LREE and HREE was caused by different mobility of complexes formed by these elements in aqueous fluids. The second stage includes recrystallized LREE-poor, Y-HREE-rich allanite with variable Ca, Al, Mg, and REE-fluorocarbonates. The alteration products from both stages demonstrate higher Fe3+/(Fe2+ + Fe3+) ratios and a negative Ce anomaly. These features point to the alkaline, low-temperature, and oxidized nature of the fluids. The differences in mobility and solubility of respective ligands show that the fluids from the first stage may have been dominated by Cl, whereas those of the second stage may have been dominated by F and CO2 (and PO4 in case of one sample). The inferred chemistry of the fluids resembles the overall geochemical signature of the composite dykes, indicating a major contribution of the hydrothermal processes to their geochemical evolution.

scholarly journals Leaching Kinetics of Weathered Crust Elution-Deposited Rare Earth Ore with Compound Ammonium Carboxylate

Minerals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 516
Author(s):  
Xiuwei Chai ◽  
Guoqing Li ◽  
Zhenyue Zhang ◽  
Ruan Chi ◽  
Zhuo Chen
Keyword(s):  
Rare Earth ◽  
Ammonium Acetate ◽  
Experimental Temperature ◽  
Ammonium Citrate ◽  
Molar Ratio ◽  
Utilization Rate ◽  
Ammonium Concentration ◽  
Leaching Kinetics ◽  
Weathered Crust ◽  
Leaching Efficiency

Due to the special properties of the ammonium salts, ammonium acetate and ammonium citrate were used to explore the best leaching conditions of rare earth with compound ammonium carboxylate. This paper explored the influence of the molar ratio, ammonium concentration, experimental temperature, and pH of the compound leaching agents on the leaching efficiency of rare earth and aluminum, and it analyzed the leaching process based on the leaching kinetics, which provides a new method for leaching rare earth from the weathered crust elution-deposited rare earth ore. The results showed that under the conditions where the molar ratio of ammonium acetate and ammonium citrate was 7:3 and the ammonium concentration was 0.15 mol/L, the leaching efficiency of rare earth was the highest when the pH of leaching agent was 4.0 and the experimental temperature was 313 K. Meanwhile, when CH3COONH4 and (NH4)3Cit were used to leach rare earth ore, the leaching reaction kinetics equation of rare earth and aluminum were obtained. In the temperature range of 283–323 K, the apparent activation energy of rare earth was 14.89 kJ/mol and that of aluminum was 19.17 kJ/mol. The reaction order of rare earth was 0.98 and that of aluminum was 0.79. The results were in accordance with the shrinking core model and indicate that the concentration of the leaching agent had a greater influence on rare earth than aluminum. This process can reduce the use of ammonium salt, and it is of great significance to extract rare earth elements from weathered crust elution-deposited rare earth ore and improve the utilization rate of resources.

Recovery of Lanthanides from Indonesian Low Grade Bauxite Using Oxalic Acid

2018 ◽  
Vol 929 ◽  
pp. 171-176 ◽  
Author(s):  
Eny Kusrini ◽  
Zakaria Jaka Bahari ◽  
Anwar Usman ◽  
Arif Rahman ◽  
Eko Adi Prasetyanto
Keyword(s):  
Rare Earth ◽  
Optimum Condition ◽  
Oxalic Acid ◽  
Rare Earth Elements ◽  
Acid Leaching ◽  
Experimental Result ◽  
Low Grade ◽  
Icp Oes ◽  
Temperature Dependent ◽  
Economical Method

The present work describes the extraction of lanthanide (rare earth elements, REE) from low grade bauxite using acid leaching method. The aim of this study is to obtain the best condition for extraction of lanthanides from low grade bauxite. The effect of different parameters such as temperatures and concentration of oxalic acid in leaching process were investigated. The content of La, Ce and Y elements were determined using ICP-OES. The experimental result shows that the efficiencies of lanthanide leaching are the temperature-dependent. Increasing leaching temperature from 45°C to 85°C did not improve recoveries of lanthanides. The most optimum condition was found at oxalic acid leaching of 1 mol/L, leaching temperature at 40°C, and time for 2 hours. The obtained results show that the lanthanides can be leached using oxalic axid. This finding may lead to more effective and economical method to separate lanthanides from low grade bauxite.

Enhanced leaching process of a low-grade weathered crust elution-deposited rare earth ore with carboxymethyl sesbania gum

2013 ◽  
Vol 139 ◽  
pp. 124-131 ◽  
Author(s):  
Jun Tian ◽  
Jingqun Yin ◽  
Xuekun Tang ◽  
Ji Chen ◽  
Xianping Luo ◽  
...  
Keyword(s):  
Rare Earth ◽  
Low Grade ◽  
Leaching Process ◽  
Sesbania Gum ◽  
Weathered Crust

Factors influencing the release rate of uranium, thorium, yttrium and rare earth elements from a low grade ore

2012 ◽  
Vol 39 ◽  
pp. 165-172 ◽  
Author(s):  
D.J. Sapsford ◽  
R.J. Bowell ◽  
J.N. Geroni ◽  
K.M. Penman ◽  
M. Dey
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Release Rate ◽  
Low Grade ◽  
Factors Influencing

Separation of Uranium and Rare Earth Elements with High Purity from Low-Grade Gibbsite-Bearing Shale Ore by Different Chelating Resins

2012 ◽  
Vol 33 (4) ◽  
pp. 482-489 ◽  
Author(s):  
Mohammed F. Hamza ◽  
Ibrahim E. El Aassy ◽  
Fadia Y. Ahmed ◽  
Adel A.-H. Abdel-Rahman ◽  
Ayman M. Atta
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
High Purity ◽  
Low Grade ◽  
Chelating Resins

Interactions of Simulated High Level Waste (HLW) Calcine with Alkali Borosilicate Glass

2003 ◽  
Vol 807 ◽  
Author(s):  
S. Morgan ◽  
R. J. Hand ◽  
N. C. Hyatt ◽  
W. E. Lee
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Borosilicate Glass ◽  
Glass Frit ◽  
High Level Waste ◽  
Second Stage ◽  
Mixed Alkali ◽  
High Level ◽  
Simulated High Level Waste ◽  
Fuel Reprocessing

ABSTRACTThis study looks at the interactions between simulated calcined high level waste from fuel reprocessing and mixed alkali borosilicate glass frit in the early stages of melting, and the possibility of the formation of yellow phase during these stages. Simulant “calcine” from a full scale inactive trial (Magnox: oxide “blend” 25:75) was pre-mixed with alkali borosilicate glass, to achieve a 25wt% waste loading, and melted at 1050°C at various times. It is shown that dissolution occurs in two separate stages; the first involves formation of a low density CsLiMoO4 fluid, which separates and forms a yellow/green layer on the surface of the melt, accompanied by some dissolution of rare- earth elements (Nd, Ce, Gd) and Zr from the waste into the glass matrix. The second stage entails more extensive migration of these rare-earth elements into the glass, and the disappearance of the surface layer on the melt. The glass appears more homogenized at the later stages of melting, but still contains undissolved particles of calcine after 16 minutes.

Sign in / Sign up

Export Citation Format

Share Document