Assertion: molybdenum's ore | /r/HasProperty | principal
Facets:
Source sentences:
text: Molybdenum is mined as a principal ore and is also recovered as a byproduct of copper and tungsten mining.
text: It is mined as a principal ore, and is also recovered as a byproduct of copper and tungsten mining.
text: Molybdenum is mined as a principal ore but is more commonly recovered as a by-product or co-product from copper and tungsten mining.