Responsible Management of the Kışladağ Heap Leach Facility

What is heap leaching?

Heap leaching starts with placing crushed ore onto a dedicated, lined area, called a heap leach pad, using conveyors. New ore is stacked in layers known as “lifts,” which are separated by liners constructed of high-density polyethylene membranes. Diluted cyanide solution is irrigated through the stacked ore to leach out gold. The interlift liners direct the gold-laden solution to a system of collection pipes leading to lined ponds before it is pumped to a processing plant. Dissolved gold is recovered at the adsorption, desorption and regeneration (ADR) plant using activated carbon and further refined into gold doré.

How does Eldorado responsibly manage its heap leach facilities?

At Kışladağ, Eldorado operates the South Heap Leach Pad and commenced stacking on the newly constructed North Heap Leach Pad in July, 2023.

Responsible water management is a top priority in the design and operation of our heap leach facilities. The mine is bounded by a series of collection ditches that divert non-contact water around the site, while all contact water within the site, including the heap leach facilities, is collected in ponds for treatment and use. All ponds, including those containing cyanide solution, are lined with double high-density polyethylene membranes and fitted with leak detection pipes and pumps. All ponds are designed to withstand, at minimum, a 100-year, 24-hour storm event. Ponds are covered with floating high-density polyethylene HDPE balls to reduce evaporation and to inhibit wildlife contact with the cyanide solution. Continuous treatment of contact water and recirculation of process solution mean that Kışladağ recycles most of the water it withdraws.

In addition to the heap leach facility process ponds, there are several additional ponds available, including a dedicated storm water event pond to contain excess overflow solution and a second to manage a storm water event that exceeds the one-in-100 year condition. Facilities are designed to keep water and solution in a closed circuit. An emergency hydrogen peroxide detoxification circuit is in place to reduce the cyanide concentration of solution that may be discharged under extreme circumstances.

As water is limited in the region, local communities are supplied with potable water from sources several kilometers away from the mine site. Eldorado supported the construction of potable water infrastructure in the region and continues to support the maintenance of this infrastructure as discussed in the Community Investment section of this report.

Once ore leaves the crushing plant at Kışladağ, it travels via electric conveyors for kilometers to reach the heap leach pad, mitigating significant quantities of GHG emissions that would result from truck haulage as an alternative transport method. Opportunities in support of our Climate Change Strategy and GHG emissions mitigation target are under investigation for the heap leach facilities, including energy efficiency measures for the conveyor system and the process solution pumping circuit.

Kışladağ has maintained an environmental management plan since before it entered production that includes an extensive monitoring program for elements such as surface water and groundwater, flora and fauna, waste and hazardous waste storage, as well as social factors. The mine uses progressive reclamation techniques to rehabilitate areas no longer needed for operations in alignment with SIMS Standards and international framework.

Eldorado is a signatory to the International Cyanide Management Institute (ICMI). As a requirement in SIMS, the Kışladağ mine adheres to the International Cyanide Management Code (ICMC), a voluntary certification program of best practices for the management of cyanide in gold mining and was recertified for a fourth time following an independent audit in 2022.

Detailed technical information about Kışladağ’s heap leach facilities can be found in the latest Technical Report on our website.