| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for recovering high purity cerium compound in high yield in a short time, to be concrete, recovering cerium as cerium (IV) ammonium nitrate from acid solutions containing cerium, e.g. etching waste fluids and the like. SOLUTION: This method for manufacturing cerium (IV) ammonium nitrate is characterized by precipitation of cerium (IV) ammonium nitrate crystals by increasing nitric acid concentration in an acid aqueous solution containing at least trivalent cerium, tetravalent cerium, ammonium ion, and nitric acid and metals having 0.7 to 1.6 V of oxidation voltage under 2 or less of pH. |
