• Sulfuric acid baking and leaching of rare earth

    2018-8-1  Although sulfuric acid baking is one of the main processing routes for extraction of rare earth elements from monazite, the chemistry involved is not well understood. In this study, a combination of chemical analysis and standard characterisation techniques (XRD, SEM-EDS, FT-IR and TG-DSC) was used to identify reaction processes occurring during the sulfuric acid baking of monazite between 200

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  • Sulfuric acid baking and leaching of rare earth

    It was observed that the sulfation reaction of monazite with acid was virtually complete after baking at 250 °C for 2 h, resulting in >90% solubilisation of rare earth elements, thorium and phosphate. After baking at 300 °C, a thorium phosphate type precipitate was formed during leaching, leading to a sharp decrease in extraction of thorium and phosphate, but the leaching of rare earth elements reached nearly 100%.

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  • Sulfuric acid baking and leaching of rare earth

    Monazite, a rare earth and thorium bearing phosphate mineral, is one of the major minerals used for the production of rare earth elements. Although sulfuric acid baking is one of the main processing routes for extraction of rare earth elements from monazite, the chemistry involved is not well understood.

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  • Sulfuric Acid Baking and Leaching of Rare Earth

    The rare earth phosphate mineral is converted to rare earth sulfate which dissolves in a subsequent water leach. As the bake temperature increases above 300 °C, thorium becomes less soluble. Although acid baking is practised in industry, the bake reactions are not well understood.

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  • ect of Sulfuric Acid Baking and Caustic Digestion on ...

    2020-6-12  of REEs (3.4% total rare earth oxide), the normal acidic leaching e ciency of REEs reached only 60–70%. By introducing sulfuric acid baking and caustic digestion, the REE-leaching e ciency was significantly improved. After sulfuric acid baking at 2.0 acid/solid ratio and 200 C for 2 h, the leaching

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  • Minerals Free Full-Text Effect of Sulfuric Acid Baking ...

    To improve the recovery of rare earth elements (REEs) from a refractory ore, this study investigated two different chemical decomposition methods, namely sulfuric acid baking and caustic digestion, with their respective leaching processes.

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  • Sulfuric Acid Leaching of Heavy Rare Earth Elements

    2020-10-16  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)

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  • Optimization of Acid Leaching of Rare-Earth Elements

    2016-6-30  Optimization of the acid leaching process for Mongolian apatite-based ore containing rare-earth elements (REEs) was studied. The ore contained approximately 10% of REEs as total rare earth

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  • Selective Nitric Acid Leaching of Rare-Earth Elements

    2019-6-19  As seen in Fig. 2, the concentrate contained 15 rare-earth elements, among which light rare-earth elements including lanthanum, cerium, and neodymium and the heavy rare-earth element yttrium were the most prominent. Cerium, lanthanum, neodymium, and yttrium accounted for 88% of the total rare-earth content of the phosphate concentrate.

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  • Rare Earth Elements - Purification, Separation and Recycling

    2016-11-29  solvation agents for HREE. have included 2-ethylhexyl hydrogen 2-ethylhexyl phosphonate (P507 or PC-88-A) and modified versions of it and bis(2,4,4- trimethylpentyl)phosphinic acid (Cyanex 272). Naphtenic acid and related carboxylic acid derivatives have also been used, though only with limited efficiency.

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  • Sulfuric acid baking and leaching of rare earth elements ...

    2018-6-22  ACCEPTED MANUSCRIPT SULFURIC ACID BAKING AND LEACHING OF RARE EARTH ELEMENTS, THORIUM AND PHOSPHATE FROM A MONAZITE CONCENTRATE: EFFECT OF BAKE TEMPERATURE FROM 200 – 800°C John Demola,b, Elizabeth Hoa,*, Gamini Senanayakeb,* aANSTO Minerals, Australian Nuclear Science and Technology Organisation, New Illawarra Rd, Lucas Heights,

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  • Minerals Free Full-Text Effect of Sulfuric Acid Baking ...

    To improve the recovery of rare earth elements (REEs) from a refractory ore, this study investigated two different chemical decomposition methods, namely sulfuric acid baking and caustic digestion, with their respective leaching processes. The studied lateritic ore contained goethite (FeOOH) as a major constituent with REEs scattered around and forming submicron grains of phosphate minerals ...

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  • SULFURIC ACID BAKING OF MONAZITE FOR RARE EARTHS

    2020-7-18  The rare earth phosphates are converted to sulfates which dissolve in a subsequent water leach. Sulfuric acid baking was first applied to rare earth ores in the early 1900’s for processing of mineral sands concentrates in the United States. Early acid bakes wereat 250

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  • Effect of Sulfuric Acid Baking and Caustic Digestion on ...

    2021-3-10  Abstract (summary): To improve the recovery of rare earth elements (REEs) from a refractory ore, this study investigated two different chemical decomposition methods, namely sulfuric acid baking and caustic digestion, with their respective leaching processes. The studied lateritic ore contained goethite (FeOOH) as a major constituent with REEs scattered around and forming submicron grains of ...

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  • Dehydration of Orthophosphoric Acid Analytical

    2021-3-12  Phosphoric Acid Diethylmethylammonium Trifluoromethanesulfonate-Based Electrolytes for Nonhumidified Intermediate Temperature Fuel Cells. ... Sulfuric acid baking and leaching of rare earth elements, thorium and phosphate from a monazite concentrate: Effect of bake temperature from 200 to 800 °C. Hydrometallurgy 2018, 179 , 254-267.

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  • Rare Earth Elements - Purification, Separation and Recycling

    2016-11-29  The supply issue of rare earth elements (REE) has become an increasingly important issue both economically and politically. Their industrial importanc e continues to increase while most production is located China, which makes the supply potentially vulnerable. As REE are vital for

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  • Potential New Rare Earth Elements Supply from

    2020-1-21  A new REE recycling technology developed by Precision Periodic involves using a nanofiltration system to extract and separate rare earth metals from phosphoric acid and waste. As reported in Mining, the filter captured 40-60% of the rare earth elements and radioactive elements

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  • Extraction of rare earth elements from a contaminated ...

    Rare earth elements (REEs) contamination to the surrounding soil has increased the concerns of health risk to the local residents. Soil washing was first attempted in our study to remediate REEs-contaminated cropland soil using nitric acid, citric acid, and ethylene diamine tetraacetic acid (EDTA) for soil decontamination and possible recovery of REEs.

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  • Simultaneous Extraction of Clean Coal and Rare Earth ...

    In this study, the alkali-acid leach process was adopted to chemically clean coal tailings as well as to extract rare earth elements. Different process parameters such as sodium hydroxide (NaOH) concentration, temperature, and time were studied.

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  • Preparation of Polymeric Adsorbents Bearing

    2019-5-25  We synthesized polymeric adsorbents modified with diglycolamic acid ligands for the recovery of rare earth elements. Styrene, divinylbenzene, and glycidyl methacrylate were copolymerized by suspension polymerization in the presence of diluent mixtures of heptane and toluene. Varying the composition of the diluent mixtures changed the pore characteristics of the polymeric particles; the

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  • Rare Earth Elements Chromite

    Baking and leaching are critical steps in the hydrometallurgical extraction of rare earths from the REE-bearing minerals. Issues with materials handling, ring formation, and high acid and energy consumption are common challenges faced by the industry in this part of the flow sheet.

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  • Rare Earth Elements Chromite

    Updated Literature Review on Acid Baking and Leaching (2019) Bench Scale Optimization of Acid Baking and Water Leach. Acid Baking Equipment Review. Comparison of REE Acid Baking in Rotary Kiln and Fluidized Bed Reactor. ... The Rare Earth Elements Industry in Canada ─ Summary of Evidence.

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  • WO2016011540A1 - Acid leaching of rare earth

    The invention provides hydrometallurgical processes for the recovery of rare earth values from ore, using simple crushing without beneficiation to produce an enriched and purified mixed rare earth concentrate. Ore is crushed to a relatively coarse particle size, and then treated with relatively small amounts of acid, at a relatively modest elevated temperature, to render the rare earth ...

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  • Potential New Rare Earth Elements Supply from

    2020-1-21  A new REE recycling technology developed by Precision Periodic involves using a nanofiltration system to extract and separate rare earth metals from phosphoric acid and waste. As reported in Mining, the filter captured 40-60% of the rare earth elements and radioactive elements

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  • Precipitation of rare earth elements from acid mine ...

    N2 - Acid Mine Drainage (AMD) has been of environmental concern for decades but found to be a viable source of critical Elements (CEs), including Rare Earth Elements (REEs). The current AMD treatment methods typically use hydroxide base chemicals for neutralization which results in precipitation of ions from the solution.

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  • Rare earth elements(REE): industrial technology,

    Rare earths: industrial technology; Introduction; As this group has 17 kinds of elements, the applications of rare earth elements are diversified: compounds from chloride 46% purity and 99.9999% of single rare earth oxides. The products are various. Details of their separation methods and

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  • The Search Minerals Direct Extraction Process for Rare ...

    2016-1-22  The Search Minerals Foxtrot project in Labrador is a surface deposit enriched in the highly sought after heavy rare earth elements. Early metallurgical work investigated beneficiation of the rare earth content of the Foxtrot resource using flotation, gravity separation and magnetic separation. ... acid baking and water leaching to produce a REE ...

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  • Rare-earth element - Processing ores Britannica

    1 天前  Rare-earth element - Rare-earth element - Processing ores: All rare-earth ores contain less than 10 percent REO and must be upgraded to about 60 percent in order to be processed further. They are first ground to a powder and then separated from the

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  • Effect of Temperature on Rare Earth Elements

    2020-1-1  This research aims to recover rare earth elements contained in coal fly ash. In this study, the recovery of La, Ce, Nd, Dy and Y was done using citric acid. Magnetic phase of fly ash with particle size less than 38 μm from PLTU Tanjung Awar-awar Tuban was leached with 300 mL citric acid of 0.5 M using solid/liquid ratio of 1:10.

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  • Rare earths : science, technology, production and use

    Summary. High-technology and environmental applications of the rare-earth elements (REE) have grown dramatically in diversity and importance over the past four decades. This book provides a scientific understanding of rare earth properties and uses, present and future. It also points the way to efficient recycle of the rare earths in end-of-use ...

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