Heap Leach Closure Strategies in Semi-Arid Conditions: A Data-Driven Approach at the Öksüt Gold Mine
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Authors
Wagner, Richard
Ozbakir, Mertcan
Petry, Tom
Hesketh, Paul
Usta Ozkayhan, Pelin
Bickford, David
Issue Date
2025-10-20/2025-11-21
Type
Conference Paper
Language
en_US
Keywords
Gold , Copper , Nickel , Uranium and Other Metal Leaching
Alternative Title
Abstract
Considering the heap leach facilities operating in semi-arid climates globally, the mining industry faces an increasing need to develop long-term closure strategies that effectively mitigate environmental risks in this climate setting. This paper presents a case study on the testing approaches taken to develop a closure plan for the Heap Leach Facility at the Öksüt Gold Mine, operated by Centerra Gold located in south-central Türkiye (Kayseri Province). A suite of technical investigations has been initiated to support sustainable closure strategies that rely on the use of locally available materials and natural attenuation processes, with the aim of minimizing long-term environmental liabilities and reducing closure costs. The study evaluates key site characteristics including hydrometeorology, hydrogeology, environmental geochemistry as well as the availability of suitable cover materials and project's proximity to nearby communities. The semi-arid climate, with low annual precipitation and high evaporation rates, is a critical factor influencing both the leachate generation potential and the selection of suitable closure techniques. Initial investigations have focused on characterizing the quality of the leachates generated from the heap residue, with the goal of identifying appropriate management strategies such as biological or chemical treatment, soil attenuation, evaporation, or the application of covers. The paper details the characterization strategy, including drilling and collection of representative samples, and describes the rationale for conducting laboratory-based column humidity cell tests. These tests are designed as part of a phased analysis to simulate long-term leaching behavior under site-specific conditions and provide critical data to support the selection and design of effective closure measures. The case study highlights the practical benefits of these investigations and their role in guiding the site's proactive closure planning process, and also offers scalable strategies for heap leach closure in other semi-arid regions, contributing to future research and sustainable mining practices. This initial testing and analysis will set a foundation for critical pilot-scale evaluations to further isolate key closure opportunities and optimize costs and risk.
Description
This paper was presented at the Heap Leach Solutions Conference, October 19-21, 2025, Sparks, Nevada.