A composite of rice husk (RH), caustic soda and aluminium oxide was synthesized at 500 C. The activated carbon and amorphous silica dispersed over the aluminium oxide selectively adsorbed uranium in the presence of other elements. At equilibrium time 1 h, phase ratio S/L (0.1 g/10 ml), pH ¼ 5 and uranium initial concentration 120.6 mg/l uranium adsorption efficiency was 96.35%. The uranium stripping efficiency from the load RHA-alumina composite fulfilled 99.9% at 1 h equilibrium time, a phase ratio (S/A) of 0.05 g/10 ml and 0.5 mol/l HNO 3 . The scanning electron microscopy photos revealed that the rice husk ash (RHA)-alumina composite has vacant or regular cavities before the adsorption, and the cavities are fully occupied by uranium after adsorption. The Fourier transform infrared spectroscopy shows a more broadening of the band t ¼ 3526 and 3462 cm À1 which was ascribed to the uranium adsorption. The composite adsorbed 93.75% of uranium from a waste sample. The uranium adsorption exhibited a Langmuir isotherm.
In this manuscript, efficiency of the used organic solvent for recovering, separating and producing highly purified zirconium oxide from zirconium chloride leach liquor of Rosetta white zircon concentrate was investigated. Zircon mineral was thermally decomposed with caustic soda, cooled, washed with distilled water and then dissolved in hydrochloric acid. Zirconium extraction efficiency reached 91.4% using 10% bis-(2-ethylhexyl) phosphate dissolved in kerosene, 15 min contact time and volume phase ratio O/A 1:1 after 3 stages. Zirconium re-extraction efficiency reached 99.95% using the following optimum conditions 4 molL−1 H2SO4 as an effective stripping agent, 15 min contact time and volume phase ratio O:A 1:1 after 2 stages. Finally, Zr (OH)4 was precipitated in presence and absence of H2O2 by NH4OH solution, filtrated, rinsed with double distilled H2O to remove any impurities several times and dehydrated at 200 °C for 2 h. From XRF and EDAX analysis the produced zirconium oxide in presence of H2O2 is purer than that produced in absence of H2O2.
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