Name and Location
Çöpler copper sulphide project, Erzincan, Turkey.

Client
Alacer Gold.

Project Description
A definitive feasibility study (DFS) for the processing of sulphide ore through whole-ore pressure oxidation (POX) at the Çöpler gold mine has demonstrated the robustness of the project.

According to the DFS, the Çöpler deposit will continue to be mined by a contractor using conventional truck and shovel methods.

Three openpits are being mined for oxide ore, which will ultimately converge into a single openpit over the life of the sulphide project.

During the preproduction phase of the sulphide project, mined sulphide ore will be stockpiled while oxide ore will be placed on the heap-leach pad.

At March 31, sulphide ore totalling two-million tonnes at 4.9 g/t of gold had been stockpiled.

The planned throughput of the POX plant is based on a nominal 5 000 t/d or 1.8-million tonnes a year. Gold recoveries are expected to average 94% from sulphide ore.

The ore will be crushed and milled to a slurry using water in a conventional grinding circuit. The slurry will be pumped into the acidulation circuit, where it will be treated with acid to reduce the carbonate levels in the ore.

The slurry will be pumped to the autoclave circuit, comprising seven individual pressure vessels, where the contained sulphide minerals will react with oxygen gas at high temperature and pressure to convert gold and copper into recoverable forms. The hot slurry from the last pot will be discharged through two flash vessels, in which the temperature and pressure of the oxidised slurry will be reduced. Steam from this process will be used to preheat the autoclave circuit feed slurry, making the POX process autogenous, with all the energy required to maintain the process during normal operations derived from the oxidation of the sulphide sulphur contained in the Çöpler ore.

The gold-bearing solids will be processed in a conventional cyanide-leach and carbon-in-pulp (CIP) gold recovery circuit.

Following the CIP circuit, the cyanide in the tailings slurry will be destroyed in the cyanide detoxification circuit.

The tailings will then be pumped to the lined tailings storage facility, about 1.5 km east from the processing plant.

Copper-bearing liquid will be treated with a reagent to recover the copper as a high-grade synthetic sulphide concentrate, which will be shipped to a copper smelter for further processing.

Heap-leach processing will continue at current rates of stacking during the sulphide project preproduction phase until the end of 2017. Ore will be crushed and agglomerated before being placed on the heap-leach pad, where gold will be leached into a solution and collected for processing in an adsorption/desorption recovery circuit.

Gold will be poured as doré bars for shipment to a third-party precious metals refinery.

Heap-leach gold production will continue in 2018 and 2019 at reduced rates, stemming from intermittent stacking of the highest-grade heap-leach ores from the pits until ultimate capacity of the heap-leach pad is reached and residual ounces are collected from the heap leach. Gold recoveries from the heap leaching of oxide ores are expected to average 70%.

Net Present Value/Internal Rate of Return
Not stated.

Value
Total preproduction capital is estimated at $660-million.

Duration
Alacer expects to receive all the required permits for the project in the first quarter of 2015, with construction starting in the second quarter of 2015.

The commissioning of the POX is expected towards the end of 2017.

Latest Developments
Alacer Gold has increased the production expectations from its flagship Çöpler mine from between 180 000 oz and 200 000 oz to between 190 000 oz and 210 000 oz.

The higher production will result from increase oxide production from 2015 to 2019, as the proposed sulphide plant at the Çöpler mine is brought into full production.

Key Contracts and Suppliers
None stated.

On Budget and on Time?
Not stated.

Contact Details for Project Information
Alacer Gold, tel +1 303 292 1299, fax +1 303 297 0538 or email info@alacergold.com.