Title:
過硫酸成分を含む硫酸溶液中の酸化剤濃度の低下抑制方法
Document Type and Number:
Japanese Patent JP6881551
Kind Code:
B2
Abstract:
According to the present invention, a sulfuric acid solution which contains, as an oxidizing agent, a persulfuric acid component such as peroxomonosulfuric acid, a peroxomonosulfuric acid salt, peroxodisulfuric acid or a peroxodisulfuric acid salt, and in which nitrogen oxide ions are present as impurities that promote a decrease in the concentration of the oxidizing agent, is exposed to a gas that is inert to the sulfuric acid solution containing a persulfuric acid component. While the inert gas is not restricted as long as the gas is not reactive with a sulfuric acid solution that contains a persulfuric acid component, air or a nitrogen gas (N2) is preferable as the inert gas from the viewpoint of safety or the production cost. Consequently, by suppressing a decrease in the concentration of an oxidizing agent in a sulfuric acid solution containing a persulfuric acid component, a decrease in the concentration of an effective oxidizing agent is able to be minimized even if nitrogen oxide ions, which are impurities that cause a decrease in the concentration of the oxidizing agent, are mixed in the sulfuric acid solution.
Inventors:
Haruyoshi Yamakawa
Iseriichi
Iseriichi
Application Number:
JP2019203551A
Publication Date:
June 02, 2021
Filing Date:
November 08, 2019
Export Citation:
Assignee:
Kurita Water Industries Ltd.
International Classes:
C25F7/00; C25D11/08; H01L21/304
Domestic Patent References:
| JP63153825A | ||||
| JP7090628A | ||||
| JP9064005A | ||||
| JP11036089A | ||||
| JP2008084903A |
Foreign References:
| US6605548 |
Attorney, Agent or Firm:
Yuji Hayakawa
Keisuke Murasame
Keisuke Murasame