| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of manufacturing ion-exchange zeolite without substantially discharging nitrate nitrogen and metal ions. SOLUTION: The balance of a nitrate aqueous solution and a metal nitrate aqueous solution used for ion-exchange is efficiently separated into nitrate nitrogen, metal ions or the like. If required, they are subjected to concentration or the like, thereafter, the nitrate nitrogen is recovered as nitric acid, and then, it is reused as a nitrate. The metal ions or the like are recovered after ion-exchange into zeolite, or are recovered after precipitation by the addition of an alkali, and they are reacted with the nitric acid, and are reused as a metal nitrate. COPYRIGHT: (C)2004,JPO
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