IMO, it would make business sense for Copper Fox to either:

1. Continue to own 25% of Schaft Creek with Teck financing all costs through to production (as per JV agreement). As market value increases, they could borrow against SC asset value to finance development of other projects; or 

2. Organize an open market sale of the company.

Option 1 potentially creates higher value over a longer period of time but, while Option 2 likely delivers lower value, shareholders benefit sooner

The proceeds on selling the Schaft Creek interest to a third party would result in a big cash tax bill (if the company is sold, tax is paid by shareholders who make gains on their Copper Fox investment) and the Teck JV agreement would have to be renogotiated. 

Option 2 looks good to me!