| 摘要 |
<P>PROBLEM TO BE SOLVED: To efficiently provide a powder containing indium oxide, which has a low chlorine grade, as a major component by an inexpensive means without necessitating waste solution treatment. <P>SOLUTION: Indium hydroxide is formed by mixing an indium chloride aqueous solution and an aqueous solution of a hydroxide salt of an alkali metal while keeping the liquid temperature below 50°C and pH at 8 or higher during mixing to cause a crystallization reaction. The crystallized indium hydroxide is dispersed into an aqueous solution, in which a carboxylic acid, which has a complex formation constant with indium ion of >2.37 and <19.43 and does not contain amino group, is used and a carboxylic acid concentration is adjusted by 0.1-0.5 mol/L, while keeping pH at 8 or higher by using an aqueous solution of a hydroxide salt of an alkali metal. Then, the resulting dispersion is kept at a solution temperature of 40-90°C for 30 minutes or more, and then is filtered. The obtained powder is subjected to water washing and calcination treatment. <P>COPYRIGHT: (C)2012,JPO&INPIT |
