Method and apparatus for removing alkali metal nitrite from a nitrate-containing salt bath

摘要

Undesired nitrites are formed during the treatment of salt bath nitrided structural components of iron and steel in nitrate containing cooling baths, and they must be removed from the washing water. The build-up of nitrites can be avoided by oxidizing the nitrite in the salt bath into nitrate by passing air into the cooling bath during off-times.