Location

Rolla, MO

Session Start Date

6-11-1999

Session End Date

6-17-1999

Keywords and Phrases

Homestake Mine; Airway Failure; Mine Ventilation; Ground Control; Rock Mechanics; Internal Raise; Costs; Production Loss

Abstract

Few tasks are more important to the Ventilation Engineer than planning major airways. This paper presents a case study of the inception, design, installation, cost and performance of a 253 m long, 4.27 m diameter subsurface replacement exhaust raise and its connecting drifts. The original raise served as a component of the primary exhaustway (140 m3/s) and heat rejection sink (8MW) for the deepest production district, responsible for 45% of the mine's total ounce production. The chronology of ground control problems with the original raise and attempts to halt the unraveling are described. Planning for a replacement raise commenced once it was realized that the original raise could not be saved. Computer simulation helped size the new raise and connecting drifts. Selection of the raise location was based on a careful rock mechanics assessment. A temporary ventilation bypass system was designed to minimize production loss in event of a catastrophic failure of the old raise while the new raise was being bored. This failure occurred shortly after the temporary bypass was ready. The new raise system was completed in February 1995 at a cost of $US 1.475 million. The troubles encountered, resistance measurements, and final costs are given, and a comparison of planned and actual performance is made.

Department(s)

Mining and Nuclear Engineering

Appears In

U.S. Mine Ventilation Symposium

Meeting Name

8th U.S. Mine Ventilation Symposium

Publisher

University of Missouri--Rolla

Publication Date

6-11-1999

Document Version

Final Version

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Jun 11th, 12:00 AM Jun 17th, 12:00 AM

Replacement of a Major Ventilation Raise at the Homestake Gold Mine

Rolla, MO

Few tasks are more important to the Ventilation Engineer than planning major airways. This paper presents a case study of the inception, design, installation, cost and performance of a 253 m long, 4.27 m diameter subsurface replacement exhaust raise and its connecting drifts. The original raise served as a component of the primary exhaustway (140 m3/s) and heat rejection sink (8MW) for the deepest production district, responsible for 45% of the mine's total ounce production. The chronology of ground control problems with the original raise and attempts to halt the unraveling are described. Planning for a replacement raise commenced once it was realized that the original raise could not be saved. Computer simulation helped size the new raise and connecting drifts. Selection of the raise location was based on a careful rock mechanics assessment. A temporary ventilation bypass system was designed to minimize production loss in event of a catastrophic failure of the old raise while the new raise was being bored. This failure occurred shortly after the temporary bypass was ready. The new raise system was completed in February 1995 at a cost of $US 1.475 million. The troubles encountered, resistance measurements, and final costs are given, and a comparison of planned and actual performance is made.