Determining the Pocket Charge Design for Effective Fragmentation of Caprock in Surface Mine Blast Operations

Hyongdoo Jang; Seokmin Hong; Seunghyuk Hwang

doi:10.32390/ksmer.2023.60.4.211

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2023 Vol.60, Issue 4 Next Page

Research Paper

Determining the Pocket Charge Design for Effective Fragmentation of Caprock in Surface Mine Blast Operations 노천광산 발파시 덮개암의 효과적 파쇄를 위한 분산장약 설계 방법

31 August 2023. pp. 211-222

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Abstract

Surface mining operations often face issues due to boulders caused by caprock layers. Caprock substantially impacts the productivity of the mine by obstructing rock fracture and posing safety hazards. This study aimed to determine an optimal bench blast design for areas where caprock is present. An initial bench blast model was designed based on the Langefors method, and the effects of caprock were simulated using AUTODYN. The Scaled Depth of Burial (SDOB) was employed to evaluate the effects of pocket charge location. The simulation revealed a 15% damage improvement with only 5% of the total explosive as a pock charge. The SDOB analysis concluded that positioning of pocket charges at the 3/5 point of the caprock thickness and making up 25% of the total explosive charge effectively crushes the caprock with minimal flyrock.

Keywords

Surface blasting

Caprock

Blast-induced Damage Zone

Oversized boulders

Pocket charge

노천 광산 작업은 때때로 모암보다 강한 덮개암의 존재로 인한 문제에 직면해 있다. 덮개암은 발파 에너지의 효율적인 전달을 방해함으로써 광산의 생산성에 상당한 영향을 미침과 동시에 안전사고를 초래할 수 있다. 이 연구의 목표는 덮개암이 존재하는 지역에 대한 최적 발파 설계를 결정하는 것이다. 기준 발파는 Langefors 방법으로 설계되었으며 덮개암의 영향은 AUTODYN을 통해 분석하였다. 또한 Scaled Depth of Burial (SDOB) 방법을 통해 덮개암 파쇄를 위한 분산장약의 최적위치를 결정하였다. AUTODYN시뮬레이션 결과, 총 장약의 5% 분량의 분산장약만으로 덮개암의 파쇄도가 15% 개선되는 것을 확인하였다. 또한, 분산장약의 최적 위치는 덮개암 두께의 3/5 지점임을 SDOB 분석으로 확인하였다. 이에 따라, 비산을 최소화하면서 덮개암을 효과적으로 파쇄시키기 위한 설계는 덮개암 두께의 3/5 지점에 위치한 총 장약의 25% 분량의 분산장약으로 결정되었다.

키워드

노천광산

덮개암

발파 파쇄지역

대괴

분산장약

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Information

Publisher :The Korean Society of Mineral and Energy Resources Engineers
Publisher(Ko) :한국자원공학회
Journal Title :Journal of the Korean Society of Mineral and Energy Resources Engineers
Journal Title(Ko) :한국자원공학회지
Volume : 60
No :4
Pages :211-222
Received Date : 2023-05-25
Revised Date : 2023-07-03
Accepted Date : 2023-08-28
DOI :https://doi.org/10.32390/ksmer.2023.60.4.211

Journal of the Korean Society of Mineral and Energy Resources Engineers ISSN:2288-0291(Print) 2288-2790(Online) 한국자원공학회지

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