recovery of coal - remotely sensed data
- refractometry
- refractor
- refractor curvature
- refractor depth
- refractor dip
- refractor geometry
- refractor location
- refractor mapping
- refractor position
- refractor topography
- refractor velocity
- refractory
- refractory clay
- refractory ore
- refractory ores
- refractory-lined
- refreezing
- refrigerating plant
- refrigeration
- refringence
- refuge chamber
- refuge hole
- refuge shelter
- refuge station
- Refugian
- refugium
- refuse
- refuse conveyer
- refuse disposal
- refuse dump
- refuse heap
- refuse ore
- refuse pile
- refuse stone
- refuse tipple
- refusion
- reg
- regarding geological and mining conditions
- regarding to different planned functions of adits
- regelation