I don’t know why everybody keeps confusing Aurus, Krong, Roshal, etc. Those are not even Russian names. :)
“The mining property in Siberia was already part of Aurus”
They did own properties in Siberia at that time through "Z-geoprom", “Ore”, “Northern Ore Technologies”, etc. That particular plant shown in the movie didn’t belong to Krong or Aurus, it was Puma’s plant.
tailings pile was one of the most recent acquisitions
And Krong was dusted and pulled out of sleep to make this acquisition for free.
Krong gives them the revenue for mining the other properties.
Krong didn't have any revenues for years, otherwise, being Russian OOO company, it would reported those revenues to Russian tax agency.