University of Oulu

Riika M. Ylitalo, Zong-Xian Zhang, Pekka Bergström, Effect of detonator position on rock fragmentation: Full-scale field tests at Kevitsa open pit mine, International Journal of Rock Mechanics and Mining Sciences, Volume 147, 2021, 104918, ISSN 1365-1609,

Effect of detonator position on rock fragmentation : full-scale field tests at Kevitsa open pit mine

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Author: Ylitalo, Riika M.1,2; Zhang, Zong-Xian2; Bergström, Pekka1
Organizations: 1New Boliden Kevitsa Mine, Kevitsantie 730, Petkula, 99670, Finland
2Oulu Mining School, University of Oulu, Oulu, 90014, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 11.4 MB)
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Language: English
Published: Elsevier, 2021
Publish Date: 2021-11-09


The effect of detonator position on rock fragmentation was studied at the Kevitsa open pit mine. Five full-scale field tests were conducted where the blasts were divided into test and reference areas, and compared with each other. In the test areas, the detonators were placed at or near the middle point of the explosive column, and in the reference areas, corresponding to the conventional blasts used in the Kevitsa mine, the detonators were placed about 1–2 m above the bottom of the blast holes. The rock fragment sizes from both test and reference areas were measured and studied using shovel-mounted machine vision cameras and image analysis. Both theoretical and field studies indicated that the detonator position plays an important role in rock fragmentation, and that the detonator position in the middle of the explosive column yielded significant improvement in rock fragmentation. For example, percentages of fragment sizes x20, x50, and x80 are reduced by 10–27%, 11–30%, and 8–31%, respectively; percentage of large size fragments (>1.0 m) is reduced by 29–99%; percentage of small size fragments (<2.5 cm) is increased by 6–49%.

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Series: International journal of rock mechanics and mining sciences
ISSN: 1365-1609
ISSN-E: 1873-4545
ISSN-L: 1365-1609
Volume: 147
Article number: 104918
DOI: 10.1016/j.ijrmms.2021.104918
Type of Publication: A1 Journal article – refereed
Field of Science: 1171 Geosciences
222 Other engineering and technologies
Copyright information: © 2021 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (