Sandur Manganese

Biggest issue with Sandur is- the mining lease has only 10 yrs left.
10 yrs from now- mining revenue and profits will be a big zero.
How will you value a company whose majority of profits and revenues will become zero in just another 10 years?
This is a very unique case.

Let us say non-mining revenues and profits go up 4x in 10 yrs.

What’s the net sales/profit growth over 10 yrs in that case? (after accounting for zero mining revenues).