Details:

Personal Author:
Morrell, Roger J. ; Wilson, Richard J.
Morrell, Roger J. ; Wilson, Richard J. Less -
Corporate Authors:
United States. Bureau of Mines.
Description:
"The Bureau of Mines conducted drag cutting experiments in hard, abrasive rock in an effort to extend the capabilities of an experimental kerf-core mining machine. The basic kerf-core mining machine cannot be used in hard, abrasive rocks because of the high wear experienced by the kerf cutters. These experiments were conducted in an effort to develop a method of preweakening the rock ahead of the kerf cutters in order to reduce the high cutting loads and hence the higher wear rates experienced by the cutters. The two "preweakening" techniques studied were indenting with mechanical wedges and single and double slotting with diamond saws. The best cutter force reduction acheived with mechanical indenting was 70 pct, whereas double slotting achieved force reductions of up to 99 pct. Conceptual designs of preweakening systems that could be retrofitted onto the basic kerfing cutterhead were developed for both the indenting and the slotting techniques. A high-energy impactor with wedge bit was used for the indenting method, and high- pressure water jets were used for the slotting method." - NIOSHTIC-2

NIOSHTIC no. 10003004


Subject:
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Drag Bits (Drilling And Boring) -- Testing.
Mining Machinery.
Rock Mechanics.

Series:
Report of investigations (United States. Bureau of Mines) ; 8784
Document Type:
Report
Collection(s):
National Institute for Occupational Safety and Health
Main Document Checksum:
[+]
urn:sha256:1379de062c494ba63923d2a8e4302dede6789a327403d7a89294ef29ac789f4a
File Type:

Supporting Files

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