Some New Developments in Mine Ventilation from the U.S. Bureau of Mines.
J Mine Ventilation Soc South Africa 1978 May; 31(5):5 pages
It has been estimated that air leakages in U.S. coal mines averages over 50 percent, and for metal mines, over 25 percent. Many mines of both categories approach 80 percent leakage. Consequently, much of the Bureau of Mines ventilation research is addressed to more efficient utilization of air. This paper describes four methods directed toward more efficient utilization of air in mines.
J. Mine Ventilation Soc., South Africa, V. 31, No. 5, May 1978, PP. 85-89