IPC Subgroup
C01B 21/46 Purification; Separation
Introduced: September 1968
Last revised: January 2006
Full Title
Nitrogen; Compounds thereof > Nitrogen oxides; Oxyacids of nitrogen; Salts thereof > Nitric acid > Purification; Separation
Classification Context
- Section:
- CHEMISTRY; METALLURGY
- Class:
- INORGANIC CHEMISTRY
- Subclass:
- NON-METALLIC ELEMENTS; COMPOUNDS THEREOF