Post evaluation macroblock N1 S1 exploitation Chuquicamata underground mine

Authors: López N, S; Barindelli P, G; Videla W, J Download Paper

Cite As:
López N, S, Barindelli P, G & Videla W, J 2024, 'Post evaluation macroblock N1 S1 exploitation Chuquicamata underground mine', in Daniel Johansson & Håkan Schunnesson (eds), MassMin 2024: Proceedings of the International Conference & Exhibition on Mass Mining, Luleå University of Technology, Luleå, pp. 1044-1056.



Abstract:
The Chuquicamata Mine began operations in April 2019, transitioning from a purely open pit operation to a mixed pit-underground operation between 2019 and 2022, eventually becoming fully underground. From 2022 onwards, the primary goal has been to achieve a Ramp Up to 140 ktpd over the next seven years. During 2020, the progression and closure of the incorporated area from the macroblock N1/S1 led to six collapses in the productive area. A thorough study was conducted on the main issues related to stability problems, including mining design, mining exploitation behavior, drilling, blasting, causality analyses, and categorization analyses of various aspects. This comprehensive study enabled the identification of the main causes of stability problems. The primary cause is linked to the design of the pillars at the edge of stability. The rock mass, which is of regular and poor geotechnical condition and has a high overbreak in the drift of the production level (averaging 22%), resulted in 50% of the pillars being in a borderline condition. This particular situation necessitated a high level of excellence in the development, construction, and exploitation of the operational area. The condition of the pillars worsened due to various contributing factors, leading to a percentage analysis that determined the contribution grade (weight) of each parameter in the stability problems.