Petra Diamonds has a record of turning De Beers' unprofitable South African mines into financial successes.
According to Dr. Yang, subsidies for small or unprofitable mines and processing plants have been "largely removed."
His allies even blame the World Bank, which financed the closing of unprofitable Russian mines in the 1990's.
Both loans go directly to the budget and are conditional on Russia meeting certain requirements, including closing unprofitable mines and managing state subsidies better.
There is a kinship here with history's ambitious laborers and their largely unprofitable mines.
Deposits in Lower Silesia have proven to be difficult to exploit and the area's unprofitable mines were closed in 2000.
The stock market crash of 1929 led to a major devaluation in metal prices, rendering even the deeper mines unprofitable.
The union, which does not include Jiu Valley mine workers, was demanding Government subsidies and a halt to the closure of unprofitable mines.
Her father was an ironmaster; he owned an enormous estate in the Urals, near Yuriatin, on which there were several abandoned, unprofitable mines.
He refused to give in to the demands to free coal prices, or to increase subsidies to unprofitable mines.