Mining with crush pillars

Show simple item record Du Plessis, Michael Malan, D.F. (Daniel Francois) 2019-11-01T07:00:12Z 2019-11-01T07:00:12Z 2018-03
dc.description This paper was first presented at the AfriRock 2017 International Symposium, 30 September –6 October 2017, Cape Town Convention Centre, Cape Town. en_ZA
dc.description Part of the work described in this paper formed part of Dr Michael du Plessis’ PhD studies at the University of Pretoria. ( en_ZA
dc.description.abstract Crush pillars have been extensively applied on the Merensky Reef horizon since the late 1970s. Once in a crushed state, the residual strength of the pillar provides a local support function and must support the hangingwall to the height of the highest known parting. The design of crush pillars is mainly limited to specifying a width to height ratio (w:h) of approximately 2:1. It is also required that a pillar crushes close to the face, while the pillar is being formed. On many mines the crush pillar system is problematic owing to the difficulty of controlling pillar sizes. This is mainly caused by poor drilling and blasting practices. As a result, pillar crushing is not always achieved. Crush pillars are implemented at relatively shallow depth, the pillar dimensions have remained essentially unchanged over many years, and the impact of regional pillars and geological losses contributing to the regional behaviour of the rock mass are overlooked. In many cases the pillar system is the source of seismicity. In this paper, the influence of mining losses (potholes) and the use of sidings are discussed as possible contributors impacting on crush pillar behaviour. A limit equilibrium model implemented in a displacement discontinuity boundary element program is used to demonstrate crush pillar behaviour. The results are compared to the pillar behaviour at an underground investigation site, which supports the preliminary findings. en_ZA
dc.description.department Mining Engineering en_ZA
dc.description.librarian am2019 en_ZA
dc.description.uri en_ZA
dc.identifier.citation Du Plessis, M. & Malan, D.F. 2018, 'Mining with crush pillars', Journal of the Southern African Institute of Mining and Metallurgy, vol. 118, pp. 211-216. en_ZA
dc.identifier.issn 0038-223X (print)
dc.identifier.issn 2225-6253 (online)
dc.identifier.other 10.17159/2411-9717/2018/v118n3a3
dc.language.iso en en_ZA
dc.publisher Southern African Institute of Mining and Metallurgy en_ZA
dc.rights © The Southern African Institute of Mining and Metallurgy en_ZA
dc.subject Crush pillar behaviour en_ZA
dc.subject Limit equilibrium model en_ZA
dc.subject Regional pillars en_ZA
dc.subject Geological losses en_ZA
dc.title Mining with crush pillars en_ZA
dc.type Article en_ZA

Files in this item

This item appears in the following Collection(s)

Show simple item record