| 摘要 |
<p>PROBLEM TO BE SOLVED: To efficiently recover Pt and Pd by adding hydrogen peroxide to a nitrate solution containing Pt and/or Pd at a specific pH and after oxidation- decomposing at a specific liquid temp., adding an alkali to neutralize to a spe cific pH to precipitate a Pt and/or Pd compound to recover them. SOLUTION: As the nitrate solution containing Pt and Pd, a silver-containing nitric acid exudate of copper slime in copper refining is suitably used. Hydrogen peroxide is added into the nitrate solution in liquid of pH <1. After or during the addition of hydrogen peroxide, the liquid tamp. is adjusted to >=60 deg.C to oxidation-decompose the nitrite complex ion of Pt and Pd. After the oxidation by heating, the solution is neutralized to pH >=3 by adding the alkali. As a result, Pt and Pd in the liquid is precipitated as the hydrate. The precipitate is solid-lipid separated to separate and remove the compound of Pt and Pd from the solution. The recovered precipitate is dissolved with hydrochloric acid and Pt and Pd are separated from each other by a usual method.</p> |
