Okay, I don't have a lot of time to fully catch up or analyze but:
Challenge Started!
You have 3 turns to complete the following:
[Main] Study Metal, [Main] Study Tailings, [Main] Study Health + Metal or Tailings, [Main] Build Mine
Hidden requirements:
[Main] Study Metal
-Province will not take this
-Costs Stability - Provinces will increase Stability if they have the Economy.
-Costs Mysticism - Provinces will increase Mysticism if they have the Economy
[Main] Study Tailings
-Province will not take this
-Costs Stability - Provinces will increase Stability if they have the Economy.
-Costs Mysticism - Provinces will increase Mysticism if they have the Economy
[Main] Study Health + Metal or Tailings,
-Comboing this with Metal will be trying to prove a negative
-Comboing this with Tailings will focus on the specific harm of Tailings.
[Main] Build Mine
-Province will not take this
-Costs Stability - Provinces will increase Stability if they have the Economy.
-Requires Survey before possible(Econ -1). Survey MAY draw a blank, requiring more than one attempt.
-May require new settlement before possible
We have 3 turns.
The failure point is running out of Mysticism and running out of time to Build Mine(which requires 3 actions on three turns)
Balanced Policy is the best way to get it, because there's no Progress policy actions available aside from Study Health that can help.
[X] Yes, send out the warriors (-5 Martial, -2 Econ)
[X] Attempt peaceful contact
[X] Survey Lands (-1 Econ, improved odds of success)