| 摘要 |
<p>PURPOSE:To recover easily yttrium by propagating microorganisms by an activated sludge method in an aq. soln. contg. yttrium, and capturing selectively the yttrium by the propagated microorganisms. CONSTITUTION:An aq. soln. contg. a trace amt. of yttrium is put together with a soln. contg. org. material and activated sludge added with nitrogen source and phosphorus source in an aeration tank and are stirred to propagate microorganisms. When the mixture is filtered, the activated sludge contg. yttrium in several thousand times of concn. is obtd. Such activated sludge is dried and burned, and a mineral acid, such as hydrochloric acid, is added to the residue of combustion and is dissolved under heating. The precipitate of the hydroxide formed after neutralization is filtered. The precipitate is again dissolved by an acid under heating and thereafter a satd. aq. oxalic acid soln. is added thereto and the soln. is allowed to cool. The oxalate precipitate formed by the cooling is filtered and heated, whereby the yttrium oxide is obtd.</p> |
