IPC Subgroup
E21C 41/18 for brown or hard coal
Introduced: January 1990
Last revised: January 2006
Full Title
Methods of underground or surface mining; Layouts therefor > Methods of underground mining; Layouts therefor > for brown or hard coal
Classification Context
- Section:
- FIXED CONSTRUCTIONS
- Class:
- EARTH OR ROCK DRILLING; MINING
- Subclass:
- MINING OR QUARRYING
Related Keywords
mining COAL