The design, implementation and optimization of casting blasts in strip mining

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:400826

Workman, J L ^[1]

---

1. Calder and Workman, Inc., Washburn, ND (United States)

This paper describes experience in designing and implementing casting blasts over the past fifteen years. Important design parameters such as powder factor, burden and spacing, blast pattern geometry, front row burden and toe distance, pit width versus height, blast length, explosive selection, millisecond delay timing and tie-in types are discussed. Active highwall presplitting is often an important technique to incorporate into casting blasts. Currently mines are finding it advantageous to angle presplit to enhance the stability of the resulting highwall. Experience with angle hole presplitting is discussed. When casting is introduced in a dragline mine, changes to the dragline operating methods are often necessary. Techniques for operating the dragline in these pits are described. Cost is always an important consideration when new techniques are introduced at a mine. The economics of increased stripping rates and coal shipments resulting from cast blasting is compared to conventional, non-blasting techniques with the same dragline. It is observed that for direct cast percentages beyond 25 percent costs are quite favorable.

• OSTI ID: 400826
• Report Number(s): CONF-950247--
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
COAL MINING
DRAGLINES
EXPLOSIVE FRACTURING
OPERATION
OVERBURDEN
REMOVAL
SLOPE STABILITY
SURFACE MINING