Eldorado Gold has decided to resume mining, crushing, stacking and heap leaching at its Kisladag gold mine, in Turkey, and suspended plans to build a $500 million processing plant.
The decision comes following the receipt of metallurgical test work on material placed on the heap leach pad last year.
Not only will this move defer a significant amount of capital expenditure for the company, it is also expected to help production rise to 390,000-420,000 oz in 2019, compared with 349,147 oz in 2018, a year when Eldorado suspended mining operations at Kisladag due to lower than expected gold recoveries.
Eldorado’s President and CEO, George Burns, said: “The decision to restart mining and heap leaching at Kisladag is supported by improved heap leach recoveries and confirmed by a revised heap leaching plan developed in early 2019. The revised heap leaching plan results in favourable economics when compared to milling, without the risks associated with the construction and financing of a $500 million project.”
On October 23, 2017, the company provided an update on Kisladag operations based on laboratory testwork undertaken during the September quarter of that year, which indicated that lower recoveries were expected from the zone of mineralisation located around the base of the open pit where mining was underway.
Based on available information, in the March quarter 2018, Eldorado elected to suspend mining in order to evaluate processing options. Following a year of engineering and testwork, in October 2018 the company announced that the Board of Directors had approved the advancement of a mill project. Subsequent to that announcement, gold recovery from the leach pad increasingly exceeded expectations. The company then focused testwork and analysis on the viability of resuming mining and heap leaching at Kisladag.
In parallel to mill engineering and analysis, testwork to extract maximum value from material already placed on the heap leach pad and the remaining reserves was ongoing throughout 2018.
Approximately 900,000 t of ore was placed on an inter-lift lined test pad in the March quarter of 2018. Late in the year, results from this pad were showing recoveries of approximately 58% from an extended leach cycle approaching 250 days (compared with around 40% recoveries from the original 90-day column tests).
In early 2019, the company analysed the new data and developed revised heap leaching plans, showing improved economics for the heap leaching scenario, hence the recent decision.
Eldorado said mining was expected to recommence by the end of this quarter, with the three-year guidance of 145,000-165,000 oz (2019), 240,000-260,000 oz (2020) and 75,000-95,000 oz (2021) based on mining and stacking an initial 22 Mt of ore grading over 1.1 g/t over this period, as well as continuing to leach the material currently on the pad.
This would help overall group production go to 390,000-420,000 oz in 2019, 520,000-550,000 oz in 2020 and 350,000-380,000 oz in 2021.
Eldorado said on Kisladag: “While the mill project has been suspended, the project remains viable in the short-term. The viability of the mill project will continue to be assessed in light of the results from ongoing heap leach metallurgical testwork on deeper material and in view of other investment opportunities within the portfolio,” the company said.
The other piece of exciting news within the company’s results was developments at its Lamaque mine in Quebec, Canada.
The company poured first gold from the Sigma mill at Lamaque in December and, in the March quarter, the mine is expected to declare commercial production. This should set the operation up to produce 100,000-110,000 oz of gold in 2019 from the mining and processing of over 500,000 t of ore at an average grade of 7 g/t Au.
Burns said: “At Lamaque, we are very pleased with the performance of our project team who delivered the first gold pour from the Sigma mill in less than 18 months since acquisition.”
In addition, exploration success at Lamaque – which includes significant resource conversion in the C5 orebody, in particular – has led the company to review options to increase throughput at the Sigma mill.
Eldorado said: “The mill has a refurbished nameplate capacity of 2,200 t/d and the potential to expand to its former capacity of 5,000 t/d with a purchase and installation of a SAG mill. Based on planned drilling and the potential conversion of inferred resources in C4, C5 and C6, the company expects to explore options to increase mill feed.”
The Lamaque underground mine is currently expected to produce 125,000-135,000 oz of gold in both 2020 and 2021.