Influence of deceleration intervals on the amplitudes of stress waves during the explosion of a system of borehole charges

Currently, many open pits there is a problem of substandard pieces of rock mass coming out after an explosion. Substandard pieces, most often, arise in the central part of the block, between the wells, due to poor development of this zone. This problem arises due to the fact that the amplitude of the stress waves from the explosion of charges in this area is much lower than near the wells. This article provides a brief overview of methods for calculating deceleration intervals; a model of a granite block with blastholes charged with ANFO was built; the simulation of the interference of voltage waves in the Ansys software package was carried out; the dependences of the voltages at the wave front on the time of the process are constructed, and the economic efficiency of the use of electronic and nonelectrical (NSI) initiation systems is calculated. Modeling showed that with the correct selection of the deceleration interval, it is possible to increase the amplitude of stress waves in this zone due to the interference of stress waves, thereby improving rock crushing and reducing the percentage of substandard pieces of rock mass. To ensure the proposed deceleration interval, it is necessary to use the electronic initiation system I-kon III, which provides a minimum step of the deceleration interval of 0.1 ms.

Keywords: blast, short-delayed blasting, voltage, interference, rock, granite, borehole, quarry, oversized.
For citation:

Dolzhikov V. V., Ryadinsky D. E., Yakovlev A. A. Influence of deceleration intervals on the amplitudes of stress waves during the explosion of a system of borehole charges. MIAB. Mining Inf. Anal. Bull. 2022;(6−2):18—32. [In Russ]. DOI: 10.25018/0236_1493_2022_62_0_18.

Acknowledgements:
Issue number: 6
Year: 2022
Page number: 18-32
ISBN: 0236-1493
UDK: 622.235
DOI: 10.25018/0236_1493_2022_62_0_18
Article receipt date: 14.01.2022
Date of review receipt: 29.04.2022
Date of the editorial board′s decision on the article′s publishing: 10.05.2022
About authors:

Dolzhikov V. V., Cand. Sci. (Eng.), Associate Professor at the Department of Explosives, http://orcid.org/0000-0001-8851-2913, Saint Petersburg Mining University, 199106, St. Petersburg, 21st Line, 2, Russia, e-mail: Dolzhikov_VV@pers.spmi.ru;
Ryadinsky D. E., 6th year student of the specialization “Explosives”, Saint Petersburg Mining University, 199106, St. Petersburg, 21st Line, 2, Russia, e-mail: riadinskii.d@mail.ru;
Yakovlev A. A., 6th year student of the specialization “Explosives”, Saint Petersburg Mining University, 199106, St. Petersburg, 21st Line, 2, Russia, e-mail: aleksej.yakovlev.98@mail.ru.

For contacts:

Vadim V. Dolzhikov, e-mail: Dolzhikov_VV@pers.spmi.ru.

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