Rare Metal Extraction & Processing: Poster Session
Sponsored by: TMS Extraction and Processing Division, TMS: Hydrometallurgy and Electrometallurgy Committee
Program Organizers: Hojong Kim, The Pennsylvania State University; Shafiq Alam, University of Saskatchewan; Harald Oosterhof, Umicore; Neale Neelameggham, Ind LLC; Takanari Ouchi, The University of Tokyo

Monday 6:00 PM
February 27, 2017
Room: Hall B1
Location: San Diego Convention Ctr

Session Chair: Xiaofei Guan, Harvard University; Hojong Kim, The Pennsylvania State University

F-83: Adsorbents for Selective Recovery of Heavy Rare Earth Elements: Takeshi Ogata1; Hirokazu Narita1; Mikiya Tanaka1; 1National Institute of Advanced Industrial Science and Technology
    There is an increasing attention to recover dilute rare earth elements (REEs) from acidic solutions in order to meet their demands and stabilize their supply chain. Adsorption is suitable for recovering target metal ions when their concentrations are low. Many adsorbents for REEs have been studied; nevertheless, there are no adsorbents in practical use. We have developed adsorbents consisting of silica gel particles modified with diglycolamic acid groups. The adsorbent has the ability to selectively adsorb REE ions from solutions containing high concentrations of base metal ions in a low pH region, and the adsorption capacities of the adsorbent for the heavy REEs were higher than those for the light ones. Moreover, this adsorbent meets the requirements for a practical adsorbent, such as high durability, easy desorption, and high adsorption rate. We therefore conclude that the adsorbent can contribute the production of heavy REEs from underutilized resources.

F-84: Behavior of Sec-octylphenoxy Acetic Acid (CA-12) in Yttrium Recovery from High Concentrated Heavy Rare Earths Mixture: Corradino Sposato1; Alessandro Blasi1; Assunta Romanelli1; Giacobbe Braccio1; Massimo Morgana1; 1ENEA - Italian National Agency for New Technologies, Energy and Sustainable Economic Development
    The behavior of sec-octylphenoxy acetic acid (CA-12) in Yttrium recovery from high concentrated heavy rare earth mixture was investigated to explore operating conditions of industrial interesting. Sodium hydroxide solution was used in order to presaponify organic phase composed by CA-12 and Tributyl phosphate (TBP) diluted in kerosene. In the investigated condition, TBP confirmed its role of phase modifier not significantly altering the extraction behavior of CA-12. CA-12-TBP system showed an high affinity in extraction for lighter rare earths such as Sm, Eu, and Gd, leaving yttrium in aqueous phase. Using a feed concentration (∑ [RE]) of 1 M, organic mixture is capable to extract around the 70% of metals in a single extraction test. Moreover for [CA-12] = 1.79 M and [RE] = 2 M the instability of extraction system occurs.

F-85: The Recovery of Bismuth from Bismuthinite Concentrate through Membrane Electrolysis: Lei Jie1; Yang Jian-guang1; 1Central South University
    A new membrane electro-deposition based process for tin recovery from stannous solid waste was introduced. Linear sweep voltammetry (LSV), cyclic voltammetry (CV) and chronoamperometry (CHR) was applied to investigate the electrodeposition of tin(II) from a stannous chloride acid electrolyte containing an amine non-ionic surfactant by using a membrane cell. Electrochemical mechanism analysis results showed that 0.3 % vol amine non-ionic surfactant facilitated the ions diffusion by increasing the diffusion coefficient from 8.32E-12 m2 s-1 to 2.85E-11 m2 s-1, and inhibited tin(II) ions reduction as well as tin nucleation and hydrogen evolution. The initial tin electrodeposition process follows the mechanism of three-dimensional instantaneous nucleation and subsequent grain growth limited by diffusion, while the tin(II) reduction process is proved to be irreversible and diffusion-controlled.

F-89: Selective Recovery of Scandium from Sulfating Roasting Red Mud by Water Leaching: Zhaobo Liu1; Hongxu Li1; Zihan Zhao1; 1University of Science and Technology Beijing
    A completely new process of selectively recovering Sc3+ without impurity of Fe3+ from Bayer red mud was developed. Prior to water leaching process, red mud needs to be digested and sulfated at a low temperature and subsequently roasted at a higher temperature for a period of time. During the roasting process, the products such as SO2, SO3 and H2SO4 molecules of thermal decomposition of sulfites including NaFe(SO4)2 and NaAl(SO4)2 could be recycled and reused as the raw materials of sulphuric acid. The leaching results indicate that roasting temperature and roasting time are the main constraint on selective leaching performance of scandium. As the sulfated red mud sample is roasted at 750 oC for 40 min and subjected to water leaching at 50 oC for 30 min, 53.0 wt.% Sc3+,<1.0 wt.% Fe3+, <0.3 wt.% Si4+ and ~8.9 wt.% Al3+ could be leaching out. Of note, the solid-liquid separation process is quite easy to be carried out.

F-90: Study of a Synergistic Solvent Extracting System to Separate Yttrium and Heavy Rare Earths: A Deep Investigations on System Behavior: Alessandro Blasi1; Corradino Sposato1; Assunta Romanelli1; Giacobbe Braccio1; Massimo Morgana1; 1ENEA - Italian National Agency for New Technologies, Energy and Sustainable Economic Development
    Yttrium is a strategical material due to its chemical properties that made yttrium fundamental in a wide range of industrial applications. For this reasons, improving the recovery of Yttrium has become a crucial focus for international research. In this scientific activity, the utilization of two extractants, 2-ethylhexyl-mono 2-ethylhexyl ester phosphonic acid (P-507) and sec-octylphenoxy acetic acid (CA-12), working in a synergistic extracting system, have been tested. A series of trials have been carried out to optimize the experimental conditions in order to separate yttrium from a mix of medium and heavy rare earths. Test with different relative concentrations of extractants and a phase modifier (TPB), with different presaponification rate, have been performed to evaluate the behavior of the synergistic system. Results are very promising to recover Yttrium with a high purity and separate heavy rare earths.