Progressive closure planning at the Magellan Mine — providing some certainty in uncertain times: a case study

Abstract

Closure planning in the mining industry has been typically left until near the end of mine life, often leaving little time, financial provision or resources for effective closure planning and implementation. Ideally proponents would commit resources and time for closure planning from the commencement of operations to optimise financial return through effective planning and enhanced efficiency. Limitations associated with closing a mine in an unplanned manner include inadequate financial provision, substandard and expensive rehabilitation, and limited access to adequate equipment and materials. The lack of time to trial rehabilitation methods, the absence of corporate memory due to personnel departures, coupled with an extended post-closure monitoring and management period, will all contribute to prolonged tenement relinquishment and continuing liability for proponents. Magellan Metals Pty Ltd (the Company) owns and operates an open-cut lead carbonate mine and processing facility, located approximately 30 km west of Wiluna in the mid-west region of Western Australia, which is approximately 730 km northeast of Perth. The Company required a dynamic system to facilitate early and effective rehabilitation and closure planning over the life of the mine. Specifically, the Company required a closure system that would facilitate the establishment of closure planning tasks, allowing for tracking of these tasks and for ongoing performance monitoring. This paper describes a change in direction in mine decommissioning planning through a case study describing the development and implementation of a progressive rehabilitation and closure system. The system applied is a spatially managed closure planning system that allows proponents to track and measure closure progress via a web-based platform. Dedicated closure tasks are established within the system and the proponent is able to allocate resources against those tasks, through standard geographic information systems (GIS) information and aerial photography. The system also integrates active links to relevant supporting documentation. The system has allowed the Company to better estimate its closure liability in an uncertain and challenging financial, political and environmental climate. Its implementation has also allowed the Company to demonstrate closure planning progress to internal and external stakeholders.