Development of novel adsorbent bearing aminocarbonylmethylglycine and its application to scandium separation

BACKGROUND: Scandium (Sc) is an important metal element in high-technology industries and the demand for Sc has been increasing annually. However, because metallurgical processes for its purification and recovery are complex, an effective technique for its separation is required. This paper reports on the development of novel adsorbents that are capable of separating Sc efficiently. RESULTS: Novel adsorbents were prepared by introducing aminocarbonylmethylglycine functional groups onto two types of support materials, silica gels for determining suitable preparation conditions and an organic resin for practical use. Scandium adsorption and separation were carried out in sulfuric media using these adsorbents. The adsorbents exhibited high selectivity to Sc from Mg, Al, Ca, Cr, Mn, Co and Ni except for Fe(III). Adsorption–desorption experiments were conducted to examine the adsorbent reusability. The adsorbents showed similar results in reuse tests without any obvious loss. CONCLUSIONS: Aminocarbonylmethylglycine functional group introduction proved effective and efficient for Sc adsorption. The newly synthesized adsorbents showed high affinity for Sc and Fe(III). Sc was separated selectively from Fe by reducing Fe(III) to Fe(II) because the adsorbent showed no affinity for divalent Fe(II). The new resin based adsorbent can be used for the practical separation of Sc.