[en] For the purpose of development of effective synthetic process of CHMI, a series of experiments were preformed on the preparation of CHMAIE, the intermediate of CHMI. For the first step, CHMA was synthesized by dropwise mixing of cyclohexylamine with maleic anhydride in toluene and 98.2% of theoretical CHMA was obtained by precipitation at 10 .deg. C for 2 hours. The optimum reaction temperature of the esterification, preparation reaction of CHAMIE from CHMA, was 68 .deg. C, and equilibrium conversion at optimum temperature was 98.5%. Equilibrium reaction time decreased with reaction temperature, and 4 hours was taken to reach equilibrium at optimum reaction temperature. Toluene in the final reaction product could be recovered by vacuum distillation. The recovery of toluene was increased with distillation temperature and 98% of toluene could be recovered at 55 .deg. C

[en] Effect of organic acid on the preparation of indium-oxalate salt from indium scraps generated from ITO glass manufacturing process was studied. Effects of parameters, such as type and concentration of organic acids, pH of reactant, temperature, reaction time on indium-oxalate salt preparation were examined. The impurity removal efficiency was similar for both oxalic acid and citric acid, but citric acid did not make organic acid salt with indium. The optimum conditions were 1.5 M oxalic acid, pH 7, 80 .deg. C, and 6 hours. On the other hand, the recoveries increased with pH, but the purity decreased. The indium-oxalate salt purity prepared by two cycles was 99.995% (4N5). The indium-oxalate salt could be converted to indium oxide and indium metal by substitution reaction and calcination

[en] Solvent extraction of lithium ion using kerosene as solvent is proposed. The extraction of lithium ion using various mixed extractants of β-diketone and neutral ligand in kerosene was performed to find the optimum extractant combination. Considering the extraction efficiency, the optimum extractant combination was 0.02 M TTA and 0.04M TOPO. For the development of lithium extraction from seawater, the effects of dominant ions in seawater were examined in various extraction conditions. The extraction efficiencies generally decreased with the concentration of dominant metallic ions and increased with pH of the aqueous solutions, but Cl"-ion showed only minor effect on the efficiency, even up to its concentration in seawater. Except for Mg"2"+ ion, more than 70% of lithium ions could be extracted at pH 10.6 from aqueous solutions with a dominant ion at its concentration in seawater

[en] Indium oxide manufacturing process from waste indium tin oxide (ITO) targets by oxalic acid was experimentally studied. The process was composed of precipitation of intermediate (indium-oxalate salt), re-crystallization and its thermal decomposition. The waste ITO targets were generated from vacuum sputtering process. The effects of operating parameters, such as solid dosage, oxalic acid concentration, reaction temperature and time, on the precipitation and re-crystallization of indium-oxalate salt were examined. Thermal decomposition to indium oxide was also investigated. The optimum reaction conditions to indium-oxalate salt were oxalic acid concentration 1.5 M, solid dosage 50 g/L, reaction temperature 80 °C and reaction time 8 hours. The purity of indium-oxalate salt prepared by precipitation and re-crystallization was 99.99% (4 N), and the salts were thermally decomposed to indium oxide at over 600 oC. The purity of the final product, indium oxide, was dependent on that of the intermediate, indium oxalate salt.

[en] For the purpose of development of the extraction process of lithium ion from concentrated water eliminated from desalination process, an experimental research on the solvent extraction of lithium ion from aqueous solutions was performed. The effects of operating parameters, such as concentration of extractant, ratio of extracting solution/aqueous solution, pH of aqueous solution, were examined. The effect of sodium chloride, the major component of sea water, was also examined. Lithium ion in aqueous solutions of pH=10.2-10.6 adjusted by ammonia solution was most effectively extracted by extracting solution composed of 0.02 M TTA and 0.04 M TOPO in kerosine. The addition of sodium chloride in lithium aqueous solution significantly interfered the extraction of lithium ion

[en] TiO₂ powders were prepared from titanium (IV) sulfate (Ti(SO₄)₂) solution using ammonia solution at low reaction temperature (80-100 .deg. C) and atmospheric pressure by hydrothermal precipitation method without calcination. The effect of reaction conditions, such as reaction temperature, initial concentration of titanium (IV) sulfate (Ti(SO₄)₂) solution, pH of mixture solution and the physical properties of the prepared TiO₂, such as crystallite structure, crystallite size were investigated. The photocatalytic activity of prepared TiO₂ was tested by the photolysis of brilliant blue FCF (BB-FCF) under the UV and the analysis of UV-VIS diffuse reflectance spectroscopy (DRS). The physical properties of prepared TiO₂ were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence spectrometer (PL), particle size distribution measurements. The crystallite size and crystallinity of prepared TiO₂ increased with increasing titanium (IV) sulfate (Ti(SO₄)₂) concentration, but photocatalytic activity decreased. The crystallite size decreased with increasing pH of mixture solution, but photocatalytic activity increased. The crystallinity and photocatalytic activity increased with increasing reaction temperature. The results showed that anatase type TiO₂ could be prepared by hydrothermal precipitation method using titanium (IV) sulfate (Ti(SO₄)₂) solution and ammonia solution at low reaction temperature and atmospheric pressure without calcination

[en] Nanosized TiO₂ particles were prepared from titanium (IV) sulfate solution using base solutions at low reaction temperature (95 .deg. C) and atmospheric pressure by hydrothermal precipitation method without calcination. The effects of preparation conditions, such as kind of base solutions (NaOH, NH₄OH, Monoethanolamine, Diethanolamine, Triethanolamine) and surfactants (CTAB, Span 20, SDBS), concentration of surfactants, temperature and pH, on the physical properties of TiO₂ particles have been investigated by XRD, SEM and Zeta-potential meter. Absorption area was also investigated by DRS in order to confirm the photocatalytic activity of the nanosized TiO₂ particles. It was turned out that, among base solutions, NaOH provides the smallest TiO₂ particles with excellent crystallinity. And cationic surfactant (CTAB) prepared smaller TiO₂ particles than any other surfactants. When CTAB is added in the concentration ratio of Ti(SO₄)₂:CTAB=10:1, TiO₂ particles with particle diameter of 5.8 nm were prepared. This is approximately 1/10 of that prepared without CTAB