Name of the Project
Tulkubash heap-leach project (formerly Tulkubash oxide project).

Location
Kyrgyz Republic.

Client
Chaarat Gold Holdings.

Project Description
The Tulkubash project has an initial reserve base of 16-million tonnes of ore grading 0.91 g/t gold, containing 470 000 oz of gold with a 76.5% recovery using heap leaching.

The reserve also contains 582 000 oz of silver at a grade of 1.13 g/t.

This material has been identified as being highly amenable to heap leaching, containing virtually no organic carbon, and total sulphur of less than 0.5%.

The mineralisation occurs in a highly fractured, brittle host rock, which lends itself to crushing without the generation of excess fines and need for agglomeration.

Average gold production has been estimated at 95 200 oz/y, with peak production during steady-state operations of more than 100 000 oz/y.

The feasibility study envisages the deposit being developed by a mining contractor using conventional openpit mining methods.

Waste and ore will be drilled and blasted on 10 m benches and excavated by 5 m3 excavators on 5 m lifts.

Highway-type haul trucks of 30 t capacity will haul waste to a near-pit storage facility and ore 5 km to the process facility. Mining will be conducted at an average rate of 50 000 t/d. 

A strip ratio of 4.2:1 over the life-of-mine is expected.

Ore hauled to the run-of-mine pad will be subject to three-stage crushing to produce a 12.5 mm product at a rate of 13 500 t/d. Crushed ore dosed with lime will be hauled to the heap by truck and dumped in 7 m lifts. 

Stacked ore will be heap-leached for an average of 60 days.

Pregnant leach solution will be collected and transferred to carbon columns at the absorption, desorption and refining plant. Gold and silver will be desorbed from carbon into a concentrated solution using a modified Zadra strip process. 

The concentrated solution will be subjected to electrowinning and smelting to produce doré suitable for refining offsite.

The heap-leach pad covers 360 000 m2. It will be built to international standards for safety and environmental protection, including a double-layered high-density polyethylene/linear low-density polyethylene liner system. The solution distribution and collection systems are internal to the heap to allow for uninterrupted operation during winter operations. The pad has a capacity of 16-million tonnes and has been designed to be expandable to enable the project to take advantage of future expansion.

The project has a 3.75-year mine life.

Potential Job Creation
Not stated.

Net Present Value/Internal Rate of Return
The project has an estimated after-tax net present value, at a 5% discount rate, of $12.1-million and an internal rate of return of 8.2%, with a payback of 3.2 years.

Value
Initial capital expenditure has been estimated at $132-million.

Duration
Full-scale construction works are expected to begin in the second quarter of 2019, with first gold expected towards the end of 2020.

Latest Developments
A notice to proceed was issued to Turkish mining contractor Çiftay Inşaat on August 31, 2018, and the contractor has now begun deploying equipment to Tulkubash. Çiftay's initial operations will focus on:

• the construction of a temporary 50-person camp for the initial construction forces;
• the partial construction of a permanent camp that will initially house 200 and then be expanded to house 360 persons in 2019);
• establishing a temporary maintenance shop;
• the construction of a 5km haul road between the mine and the process facilities;
• the construction of the Kumbel pass-to-site portion of the access road; and
• the initial clearing and grubbing of the heap leach pad area.

These advance activities are expected to lead to full-scale construction of the Tulkubash project in the second quarter of 2019.  Basic engineering for the process plant is complete and detailed engineering is in progress. The heap-leach facility design is being finalised and the application for Kyrgyz regulatory approval of the design is being compiled.

The remainder of construction activities for the Tulkubash project is estimated to cost $130-million.

So far,  the access road from the Chatkal valley to the top of Kumbel pass, the haul road bridge over the Sandalash river, and the communications infrastructure, which will serve the mine during construction and production, have been completed. 

Key Contracts and Suppliers
Çiftay Inşaat (mining contractor).

On Budget and on Time?
Not stated.

Contact Details for Project Information
Chaarat Gold Holdings, tel +44 20 7499 2612 or email info@chaarat.com.