
Designing Blast Patterns Using Empirical Formulas
Twin Cities Mining Research Center, Minneapolis, Minn . . US Department of Interior Office of Surface Mining Reclamation and Enforcement Kenneth K. Eltschlager Mining/Explosives Engineer 3 Parkway Center Pittsburgh, PA 15220 Phone Fax Keltschl UNITED STATES DEPARTMENT OF THE INTERIOR Rogers C. B. Morton, Secretary BUREAU OF MINES .