Kim Bennett
Senior Principal Mine Closure Specialist
Stantec
BIOGRAPHY
Kim has over 25 years of experience in the mining industry and has worked in the environmental consulting sector for the past 15 years.
Kim has led the development of over 45 mine closure plans and associated cost estimates for clients.
Her effective communication skills and technical capabilities, combined with her knowledge of project risk assessment, results in clients receiving the required focus and project team motivation necessary to successfully drive deliverables and efficiently complete projects.
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Kim has worked across all phases of project development, from environmental impact assessment studies through to construction-commissioning, operations, and mine closure.
Her experience also encompasses stakeholder and community consultation, coastal planning, due diligence work, development of tailings decommissioning plans, and statutory guidance on closure.
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This knowledge enables her to bring teams of appropriate technical specialists together to solve complex technical problems and develop holistic site-wide closure designs which optimize the overall post-closure outcomes and closure costs.
Using Imagery to Develop a 3D Resource Model of Waste Rock Landforms for Closure Design
Abstract
Kim Bennett: Stantec, Australia
Jared Erickson: Stantec, USA
David Blaxland: Gold Fields Ltd, Australia
Alex Langley: Gold Fields Ltd, Australia
Phil Crouse, Stantec, USA
Petina Wallace, Stantec, Australia
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Closure of large mine facilities (e.g., tailings storage facilities (TSFs)) often requires sourcing large volumes of variable material with specific characteristics.
Where feasible, identifying and sourcing appropriate material in the required volumes from local waste rock landforms (WRLs) is recognised as best closure practice. However, many WRLs are constructed during the mining process without considering the materials as a borrow resource for future mine closure.
Material investigations which characterise the composition of the material within a WRL and delineate the extents of similar materials are often constrained to the upper surfaces of the WRL.
Due to the height and variability of material within numerous WRLs, mine closure plans will often include knowledge gaps on material suitability and quantities.
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This paper will present how imagery has been used to produce a 3D resource model of two WRLs at the Gold Fields St. Ives Gold Mine, located approximately 60 kilometers south of Kalgoorlie Western Australia, and how this has supported the closure design of three TSFs located adjacent to the WRLs.
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The TSF closure plan requires sourcing various material types, including coarse fractured rock material for erosion protection, clean and competent material for the construction of new roadways and embankments, and fines material with suitable geochemical properties to support long-term vegetative growth to cover the TSF surface. Each of these closure material types will be sourced from specific pre-determined zones using the 3D resource model of the WRLs.
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St Ives and Stantec worked together to correlate mine pit geology, historic aerial imagery and/or aerial elevation data, and investigation data to develop a 3D Model that provides zones of waste rock materials having the required physical, chemical, geochemical and geotechnical properties required for cover systems.
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Mapping and delineation of the zones of similar material that can then be quantified and targeted during closure planning and implementation is key to a cost-effective method of sourcing the different material types needed for closure.
Delineations are produced through having a sound understanding of the site geology, enhanced by reviewing any details related to the mining of the deposits from which the waste rock material was excavated, including historic aerial images, and numerous material characteristic test results of samples collected near the WRL surface at targeted locations.