| A recovery process on pure alumina power from the wasted aluminum etching solution of electrolytic condenser works was studied. In order to remove the impure cations such as Fe^(3+) and Cu^(2+) from the etching solution, solvent extraction was performed, and then, Al^(3+) was precipitated by purging HCl into the solution. Thermal behaviors of the recovered materials were tasted and X-ray diffraction patterns were obtained. Finally, the recovered materials and the calcined one were observed by scanning electron microscope. As the results, more than 95% of Fe^(3+) and Cu^(2+) were removed by the solvent extraction and the precipitated phase by HCl purging was found as AlCl₃·6H₂O. The recovery ratio of aluminum component from the solution was higher than 99.3% after 40minutes of HCl purging at the purging rate of 7.2㎖/sec.. The AlC₃·6H₂O was transformed to powdery α-Al₂O₃ by calcination of the temperature about 1200℃, and the heat of phase transformation from calcined non-crystalline from to crystalline α-Al₂O₃ was about 13.7㎉/㏖. |
|
