Synthesis of highly-selective fibrous adsorbent by introducing 2-ethylhexyl hydrogen-2-ethylhexylphosphonate for scandium adsorption

Hoshina, Hiroyuki; Ueki, Yuji; Saiki, Seiichi; Seko, Noriaki

2-Ethylhexyl hydrogen-2-ethylhexylphosphonate (EHEP) is commonly used as a metal extractant because it has a particular affinity for rare-earth metals like Scandium (Sc). To develop a highly-selective polymeric adsorbent of Sc(III), EHEP was introduced as a functional group onto a polyethylene fabric with radiation-induced graft polymerization (RIGP). The adsorption performances for Sc(III) were evaluated in aqueous solutions containing Sc(III) and Fe(III) by a column test. The adsorption capacities of Sc(III) and Fe(III) until the bed volume reached 5000 were 5.22 and 0.12 mg/g, respectively. The adsorbents showed 44 times higher Sc(III) adsorption capacity than that of Fe(III). These results indicated that the grafted adsorbent containing EHEP had an extremely high selectivity for Sc(III) adsorption.