This report summarizes all relevant findings and conclusions regarding capability of high-energy projectile impact to operate effectively in an open pit environment and to successfully handle secondary breakage and bench scale problems. A silenced, aimable, mobile projectile launcher was designed and fabricated, utilizing a government-furnished smooth-bore, 90 mm cannon. The silenced launcher was tested at the contractor's test site prior to shipment to Anamax Mining Companys' Twin Buttes Mine near Tucson, Arizona. Demonstration tests were conducted at an inactive waste dump in the mine on 39 oversize boulders to determine the relationship between boulder size and projectile energy required for secondary breakage. The high energy projectile impact method was tested on an additional 23 boulders in the working mine and on 31 areas of potentially loose rock high on the pit walls. Most of the secondary breakage tests were successful and acceptable for open-pit mining purposes without producing large amounts of fly rock.
Publication Date
19760101
Document Type
CP; Final Contract Report;
Fiscal Year
1976
NTIS Accession No.
PB-257475
NTIS Price
A04
Identifying No.
OFR 99-76
NIOSH Division
TCRC;
Source Name
NTIS: PB 257 475 Available for Reference At Bureau Libraries
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