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The Ripper Excavation Method.

Larson-DA; Morrell-RJ
Proc Conf on Shaft Drilling Technology Las Vegas Inst Shaft Drilling Technol 1991 :10 pages
As part of its continuing research to strengthen the competitive position of the U.S. minerals industry by improving the efficiency of underground hard-rock mining, the U.S. Bureau of Mines is conducting research on continuous mechanical extraction systems to replace the cyclic drill-blast-muck system in common use. One product of this research is a fragmentation method called ripper cutting. This concept uses a single, wide bit that attacks the rock at a shallow angle and slow speed. Research has demonstrated that the system is capable of excavation rates exceeding those possible with conventional drill-blast and can effectively cut rock too hard for roadheaders or drum-type miners. The concept has the additional advantages of low bit wear and low dust generation. The ripper cutting system can be configured as a development machine, a hard- rock mining machine, or a shaft-sinking machine. This paper presents the results of full-scale laboratory tests conducted in both soft and hard rocks using two different cutterheads. It also includes a comparison of ripper cutting to systems currently used from the standpoint of energy efficiencies and operating costs.
Publication Date
Document Type
Fiscal Year
NTIS Accession No.
NTIS Price
Identifying No.
OP 95-91
NIOSH Division
Source Name
Proc. Conf. on Shaft Drilling Technology, Las Vegas; Inst. Shaft Drilling Technol., 1991, 10 Pp