Creating a just chromite company may be a good thing to do but giving half of it away? You must be joking.

Having road access should drop their expenses considerably and with jobs that should be the greatest benefit that they will receive. That alone should be sifficient becuse of the dollars they gain they should be able to improve their housing, water and just about everything else.
As an incentive to signing a royalty of sort based on amount ore processed and it's profitability could also be in order.
To anything above the above I flatly say No.

They do not in the common sense own all that land. Just go and read Treaty 9. They own only the reservation's land and even that can be appropriated by either government should a need arise with compensation.