The separation of zirconium and hafnium using tributyl phosphate (TBP)-Dodecane extractants in nitric acid medium was performed. Zirconium oxychloride, used as extraction feed, was obtained from the synthesis of Kalimantan zircon sand concentrate smelted using NaOH. The extraction process was carried out by dissolving chloride-based metals in nitric acid media in the presence of sodium nitrate using TBP-Dodecane as an extractant. Some of the extraction parameters carried out in this study include variations in organic phase and aqueous phase (O/A), variations in contact time, and variations in nitric acid concentration. Extraction was carried out using a mechanical shaker according to the parameter conditions. X-ray fluorescence (XRF) was used for elemental (Zr and Hf) composition analysis of the aqueous solution. The results showed that zirconium was separated from hafnium at optimum conditions with an organic/aqueous ratio of 1:5, contact time of 75 min, and an HNO3 concentration of 7 M. The resulting separation factor of zirconium and hafnium using TBP-Dodecane was 14.4887.

본 연구는 직접메탄을 연료전지(Direct Methanol Fuel Cell)에 적용가능한 양이온교환막 개발에 관한 것으로 PVA/PAM/ZrP 막을 제조하여 PAM, ZrP의 함량 및 농도 변화에 따른 막의 특성을 연구하였다. PVA/PAM/ZrP 막은 PVA에 가교제인 PAM의 함량을 7∼11 wt%로 증가시켜 제조하였으며 그 각각의 막에 80℃에서 zirconyl chloride와 Phosphoric acid solution에 침적시켜 제조하였다. ZrP의 농도를 1, 2 M로 변화시켜 메탄을 투과도, 이온전도도, 함수율 및 이온교환용량을 측정하였다. PVA/PAM/ZrP 막의 메탄올 투과도는 10/-8∼l0-6 cm2/sec, 이온전도도는 10-3~10-2 S/cm 정도 나타내었으며 함수율은 0.26∼l.17 g H2O/g membrane, 이온교환용량은 2.59∼5.1 meq/g membrane의 결과를 보였는데 이는 PVA/PAM 막과 비교하여 메탄을 투과도, 이온전도도는 각각 18%, 23% 정도 증가한 것으로 관찰되었다.

The -zirconium phosphate particles as fine as 20 nm were fabricated through solution technique using and as precursors. Stability of -Zirconium phosphate could be ensured by adding excess phosphoric acid to a stoichiometric composition Instead of using reflux route that resulted in coarsening of particles due to an inevitably long aging. The excess phosphorous incorporated in the crystal could be successfully eliminated afterwards through careful washing. Moreover, heavily agglomerated particles are observed before washing, but fairly dispersed state is found out after washing treatment. Thus, it is found that dispersed state as well as phase stability is ensured through proper washing treatment.