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Adsorption of rare earth elements in regolith-hosted clay ...

Economic exploitation of IADs is viable through REE extraction by low-cost in situ or heap leaching 8,12,15, a process that has had significant environmental impact in China 6.

Effect of Particle Size and Solution Leaching on Water ...

Currently, ion-absorbed rare earth is mainly exploited by in situ leaching. In leaching mining, solution of salt leaching agent is injected into the clay ore through the injection well, thus triggering chemical replacement reaction between ammonium ions in the leaching solution and rare earth ions adsorbed on …

Ammonia Nitrogen Sources and Pollution along Soil Profiles ...

The ammonium sulphate ((NH 4) 2 SO 4) in-situ leaching process is the most widely used extraction technology for weathered crust elution-deposited rare earth ores (WCED-REOs).Highly concentrated (NH 4) 2 SO 4, a representative leaching agent, is often used in the leaching process of WCED-REOs.However, this in-situ leaching process causes nitrogen pollution in the soil, surrounding …

Leaching behaviour of rare earth elements from low-grade ...

Effect of L:S ratio on rare earth leaching. The L:S affects the probability of contact of the rare earth ion with the leaching agent. These experiments were carried out in 3% MgSO 4 solution for 30 min of leaching time. The mass of ore was 100 g and the volume of MgSO 4 solution was such to keep an L:S of 1:1–7:1. The results are shown in Fig ...

Chelation-Assisted Ion-Exchange Leaching of Rare Earths ...

The effect of biodegradable chelating agents on the recovery of rare earth elements (REE) from clay minerals via ion-exchange leaching was investigated, with the aim of proposing a cost-effective, enhanced procedure that is environmentally benign and allows high REE recovery while reducing/eliminating ammonium sulfate usage. A processing route employing a lixiviant system …

Rare earth metals sorption recovery from uranium in situ ...

Rare earth metals sorption recovery from uranium in situ leaching process solutions. 123. Rare Met. ... A method of Baotou mixed rare earth concentrate leaching was investigated. According to the ...

Novel solution injection technology for in-situ leaching ...

The leaching solution of rare earth could be collected via diversion channels which installed on and around the bedrock. The schematic diagram of liquid injection process by in-situ leaching in weathered crust elution-deposited rare earth ores is shown in Fig. 10 and Fig. 11. Download : Download high-res image (593KB)

An overview of rare-earth recovery by ion-exchange ...

, He, Z. and Ruan, Y (2014) Novel solution injection technology for in-situ leach¬ing of weathered crust elution-deposited rare earth ores. Proceedings of the 53rd Conference of Metallurgists (COM 2014), Metallurgical Society of the Canadian Institute of Mining, Metallurgy and Petroleum (MetSoc-CIM), Vancouver, Canada.

China's ion-adsorption rare earth resources, mining ...

Heap leaching In-situ leaching Environmental damage Preservation abstract The surface mining and heap leaching of China's unique ion-adsorption rare earth resources have caused severe environmental damage, and China needs to develop and implement an integrated rare earth resource management approach for a sustainable rare earth industry.

Kinetics model for leaching of ion-adsorption type rare ...

1. Introduction. Ion-adsorption type rare earth ores (IATREO) are important source of heavy rare earth.1, 2, 3 In these ores, rare earth ions are adsorbed on the surface of clay minerals in the form of hydrated ions or hydroxyl hydrated ions.4, 5, 6 At present, they are exploited through in-situ leaching technology using a leaching agent such as ammonium sulfate solution. 7, 8 In-situ leaching ...

Minerals | Free Full-Text | Pore Structure ...

As an environmentally compliant hydrometallurgical process, in situ leaching is extensively used by the mining industry to recover rare earth from weathered crust elution-deposited rare earth ore. In the in situ leaching system, the pore structure plays a dominant role in the permeability of the rare earth orebody and is one of the most important factors that influence the leaching performance.

process for in situ leaching rare earth

Rare earth metals sorption recovery from uranium in situ leaching ... 18 Mar 2014 ... Rare earth metals sorption recovery from uranium in situ leaching process solutions ... of ion exchange resins 001×7, 005×8, D72 regarding rare earth metals .... uranium in situ leaching process solutions; Journal: Rare Metals. Read more

LEACHING CHARACTERISTICS OF RARE EARTH ELEMENTS …

leaching but was found to be insignificant as the system reached equilibrium. Solids concentration in the leaching medium has an important role in establishing the throughput capacity of the leaching system. Test results found that an increase in solids concentration had a …

Rare Earth Elements - Purification, Separation and Recycling

One significant exception to this general description is the process for extracting REE from ion adsorption clays, for example in southern China, where direct-leaching in situ-methods are used instead. In these methods, an ammonium sulfate solution is pumped into the clay deposit to …

In-Situ Leaching & Borehole Mining

In situ leaching does not include dump or heap leaching where the ore is blasted and/or dug and placed in areas specially prepared for leaching, but is reserved for the process where chemical solutions are circulated through the ore body. Although the ore may be blasted to increase permeability for in situ leaching, it is not transported.

An initial life cycle assessment of rare earth oxides ...

In-situ leach mining is now the dominating technology, given that there is less topsoil removed (i.e. about one fifth to one third as in the case of heap and tank/pool leaching), the process can be performed on site, and the environmental impacts are reduced (Du, 2001, Wu, 2005, Schüler et al., 2011). For these reasons this study focuses on in ...

Leaching Process of Weathered Crust Elution-Deposited Rare ...

To strengthen the rare earth leaching process and weaken the hydration of clay minerals for preventing landslides, it is of great importance to adopt a green and sustainable leaching agent in the industry. In this work, the leaching process of weathered crust elution-deposited rare earth ores with f …

Leaching Process and Mechanism of Weathered Crust Elution ...

The leaching processes and mechanisms of weathered crust elution-deposited rare earth (RE) ores with ammonium sulfate were investigated for their high efficiency and low consumption exploitation. The leaching process is a typical reversible heterogeneous ion exchange reaction in liquid–solid systems. The raw ore and leached tailings were analyzed by SEM and FTIR. Results …

US8979210B2 - Liquid collection process with liquid ...

A liquid collection process with liquid guiding holes for in-situ leaching an ore body to extract rare earth elements, including: 1) multiple liquid collection channels are provided in an ore body; 2) liquid guiding holes are arranged near the bottom and on both sides of the channels, and these holes and the channels jointly constitute a multi-channel mother liquid drainage and collection ...

Rare Earth Elements from Coal and By- Products: Separation ...

•Ex situ heap leach recovery & plant processing from coal mining waste and co-mined materials •In situ recovery from undisturbed sedimentary rock layers, open pits, or underground mines C. Verba, M. McKoy, T. Tarka, S. Montross, J. Yang, "Process for Extraction of …

China Wrestles with the Toxic Aftermath of Rare Earth ...

The first involved removing layers of topsoil and transporting them to a leaching pond, where acids and chemicals were used to separate the various rare earth elements from the clay, soil, and rock. The other process involved drilling holes into hills, inserting PVC pipes and rubber hoses, and then flushing out the earth using a mix of water ...

Sulfuric Acid Leaching of Heavy Rare Earth Elements (HREEs ...

The characterization process was carried out to obtain actual information from zircon tailing samples. This process showed total rare earth elements (REEs) content of 58.62%, at 9%, 1%, 1.2%, 1.7%, and 1.5% for Y, Gd, Er, Dy, and Yb, respectively. A sieving process was carried out since it was known that most heavy rare earth elements (HREEs ...

Study on Pb release by several new lixiviants in weathered ...

In this study, column leaching experiments were used to simulate in-situ leaching, and the leaching behavior and fractional changes of lead in weathered crust elution-deposited rare earth ore by different leaching agents were studied.

Readsorption of rare earth elements during leaching ...

A leaching experiment on simulated rare earth ore pillars with uneven grade distribution was conducted because of the readsorption of rare earth elements in the in situ leaching process of ion-adsorption-type rare earth ore. Results show that the readsorption of rare earth elements in the barren layer is the main reason for the decrease in rare earth concentration in the leachate, decrease in ...

Minerals | Special Issue : Leaching of Rare Earth Elements ...

This analysis was performed using different methods, such as regional rare earth mine soil surveys, in situ leaching profile monitoring, and indoor simulated leaching. The results showed that the grain size and volume curve of rare earth ore have unimodal and bimodal shapes, respectively.

Leaching Process of Weathered Crust Elution-Deposited Rare ...

To strengthen the rare earth leaching process and weaken the hydration of clay minerals for preventing landslides, it is of great importance to adopt a green and sustainable leaching agent in the industry. In this work, the leaching process of weathered crust elution-deposited rare earth ores with formate salts (ammonium formate, potassium formate, and sodium formate) was investigated.

Uranium mining by in-situ leaching

process preferably with carbonate solutions or relatively mild reagents. 6. The ore should occur at favorable depth. 7. The ore body should be of sufficient size and grade to justify the cost of production. TECHNIQUE OF IN-SITU LEACHING: Under favourable geological-hydrogeological conditions, the process of in-situ leaching is

Solute Transport Mechanism of Ion-Adsorption Type Rare ...

For the in-situ leaching mining, the mechanism of solute transport in the leaching process is directly related to the leaching rate of rare earth resources and the migration of rare earth ions and ...

Behavior and mechanism of different fraction lead leach ...

Recently, some new leaching agents without ammonium, such as magnesium sulfate (MgSO 4) and aluminum sulfate [Al 2 (SO 4) 3], have been developed to eliminate ammonia nitrogen pollution in in situ mining process of the weathered crust elution-deposited rare earth ore (WCED-REO), but they might cause heavy metal contamination.In this study, characteristics and mechanisms …

WO2016128621A1 - Method and arrangement of recovering rare ...

A method and arrangement of recovering REEs wherein the ion adsorption clay is leached in a leach solution for producing a leach slurry, which leach residue contained in the leach slurry is washed with water and a pregnant leach solution and the leach residue are separated from each other. Water is separated from the pregnant leach solution and a concentrated pregnant leach solution containing ...

Clay vs Hardrock - Ionic Rare Earths

Clay vs Hardrock Australian Securities Exchange (ASX) company code IXR Send Enquiry Ionic Clay Rare earth elements vs Hard Rock Rare Earth ElelemENTs Projects Significant project and cost advantages associated with ionic clay projects like Makutuu Mining/Processing Stages Ionic Adsorption Clay-hosted REE Hard Rock-hosted REE Mineralisation Soft material, negligable (if any) …

Minerals | Free Full-Text | Leaching Kinetics of Weathered ...

The column leaching method was used to simulate the in situ leaching technology for extracting rare earth elements from weathered crust elution-deposited rare earth ore with compound ammonium carboxylate, and the best leaching conditions of rare earth ore with compound ammonium carboxylate were obtained: the ammonium concentration of compound ...

Leaching process of weathered crust elution-deposited rare ...

To strengthen the rare earth leaching process and weaken the hydration of clay minerals for preventing the landslide, it is of great importance to adopt the green and sustainable leaching agent in the industry. In this work, the leaching process of weathered crust elution-deposited rare earth ores with formate salts (ammonium formate, potassium formate and sodium formate) was investigated.