Geotechnical Guidelines for Open Pit Closure – a new publication by the Large Open Pit (LOP) project

Authors: de Graaf, PJH; Beale, G; Carter, TG; Dixon, J Download Paper Open access courtesy of:

DOI https://doi.org/10.36487/ACG_repo/2152_120

Cite As:
de Graaf, PJH, Beale, G, Carter, TG & Dixon, J 2021, 'Geotechnical Guidelines for Open Pit Closure – a new publication by the Large Open Pit (LOP) project ', in AB Fourie, M Tibbett & A Sharkuu (eds), Mine Closure 2021: Proceedings of the 14th International Conference on Mine Closure, QMC Group, Ulaanbaatar, https://doi.org/10.36487/ACG_repo/2152_120



Abstract:
Closure planning is a fundamental requirement for all existing and planned future mines. However, there are no accepted industry guidelines for how to geotechnically and hydrogeologically assess options for open pit and waste dump closure or for advancement of the closure plan in parallel stages with overall project development and operation. Ideally, closure planning needs to consider the site setting, develop the “big-picture” strategy, and work downward from there, balancing the objectives of the operator, regulator and community. At present, too much binding detail is being included in “early-stage” closure plans that, when approved, become committed. This paper outlines the “State-of-Practice” geotechnical and hydrogeological guidelines for closure planning and implementation being developed by the Large Open Pit (LOP) project research group. The new Guidelines are intended for use by geotechnical and hydrogeological mining professionals addressing closure design criteria, risk management, detailed planning and implementation. Benchmarks are provided for stakeholders, including regulators and the community, to judge whether adequate investigations and planning have been completed for appropriate stages of overall project development. Three case studies are provided to illustrate how changes of closure approach produced a substantially better outcome