| Co-Investigator(Kenkyū-buntansha) |
WAKAMATSU Takahide Meijo University, Faculty of Urban Science, Professor, 都市情報学部, 教授 (50025897)
NIINAE Masakazu Kyoto University, Faculty of Eng., Assistant, 工学部, 助手 (50228128)
SANO Makoto Kansai University, Faculty of Eng., Assistant, 工学部, 助手 (00170811)
|
|---|
| Research Abstract |
The stripping stage of solvent extraction can be applied for the production of metal salts, metal oxide, metal powders and complex metal powders. It is called the crystallization-stripping. In the crystallization-stripping, the complex fine metal and metal oxide powders are prepared less costly in the simple process. If two or three kinds of organic phases containing different metal ions are mixed together and the crystallization-stripping is applied to the organic phase, we can make complex fine metal and metal oxide powders.
Extraction of Co, Ag, Ni, Cu, Zn, Fe and Sm were investigated using Versatic Acid and D2EHPA as extractants, and then the properties of crystallization-stripping of these metal ions were measured using oxalic acid and carbon dioxide as crystallization agents.
The crystallization of these metals takes place quantitatively within 5 min.due to the low solubility of metal oxalates. When the organic phase containing two kinds of metal ions is used for crystallization-sr
… More
tipping, the crystallization happens in the order of metal ions which have less strong affinity with the extractant. If the amount of oxalic acid corres-ponding to metal concentration in the organic phase is used, all of metal ions are precipitated as copmlex metal oxalates from the organic phase. In this case, the particle size of each metal oxalate, such as copper, nickel and zinc oxalates is different from one to other oxalates. For example, the particle size of copper, nickel and zinc oxalates is found to be 0.5,2.5 and 5mum, respectively. The sedimentation speed in aqueous solution depends on the particle size. The complex metal oxalate with good mixed state cannot be produced by the reason of particle size difference. The thermal decomposition of these metal oxalates takes place in the temperature range, 300-400ﾟC.The thermal decomposition in air gives the metal oxide powders, while the decomposition in hydrogen results in reduced metal powder. When the crystallization-stripping with carbon dioxide is applied to the organic phase containing silver and nickel, the complex metal carbonate with good mixed state can be obtained. Less
|
