Screen analysis of full-scale production blasts
Book
·
OSTI ID:398364
- Bureau of Mines, Minneapolis, MN (United States). Twin Cities Research Center
The US Bureau of Mines conducted 22 full-scale blasts to determine the effects of delay and explosive type on fragmentation. The shots were conducted over a period of 7 years in three limestone quarries and one granite quarry. Hole diameters, bench heights, and number of holes varied from 6.4- to 14-cm, 6.7- to 14-m, and 4- to 24-holes, respectively. Explosive performance and actual firing times were measured and screening was used to assess the fragmentation. The results of the timing tests in highly-bedded limestone confirmed previous studies: optimum fragmentation occurs at delays between holes of 3.3 to 16 ms per meter of burden. The fragmentation in limestone quarries showed little difference when using AN-FO as compared to higher-energy explosives, emulsions and dynamites. Water seepage affects on explosive performance, pre-existing joints, and the breakup of the stemming region were found to have a great influence on the distribution of the coarse size material.
- OSTI ID:
- 398364
- Report Number(s):
- CONF-9502142--
- Country of Publication:
- United States
- Language:
- English
Similar Records
Mine roof vibrations from underground blasts
Effects of jointing and bedding separation on limestone breakage at a reduced scale
Mine roof vibrations from underground blasts, Pilot Knob, Mo. [9 refs]
Technical Report
·
Wed Dec 31 23:00:00 EST 1969
·
OSTI ID:5308777
Effects of jointing and bedding separation on limestone breakage at a reduced scale
Technical Report
·
Mon Dec 31 23:00:00 EST 1973
·
OSTI ID:7352889
Mine roof vibrations from underground blasts, Pilot Knob, Mo. [9 refs]
Technical Report
·
Sun Dec 31 23:00:00 EST 1972
·
OSTI ID:7355802