Name of the Project
Bibiani gold project.

Location
Ghana.

Project Owner/s
Resolute Mining has struck a $105-million sales agreement with China’s Chifeng Jilong Gold Mining Co for its Bibiani gold mine. The $105-million cash consideration will comprise a $5-million deposit on the signing of the agreement and a $100-million payment on completion of the transaction, which is expected in March 2021.

The project was acquired by Resolute in 2004, and was placed on care and maintenance shortly after to allow for exploration activities to develop an economically viable, long-term, large-scale operation.

Resolute launched a review of the asset in January 2020 to consider the benefits of continuing operations at Bibiani or if another company would be better placed to continue with Bibiani.

Chifeng intends to progress the redevelopment of Bibiani as soon as is possible. “Chifeng will immediately invest the required capital, and provide the necessary expertise, to recommission Bibiani as an operating gold mine in the shortest possible timeframe,” Chifeng's executive chairperson Wang Jianhua has said.

The transaction is subject to a number of conditions, including Australian Foreign Investment Review Board approval, and Chinese and Ghanaian government approvals.

Project Description
The Bibiani project has an initial ore reserve of 5.4-million tonnes grading 3.7 g/t containing 640 000 oz of gold and mineral resources of 1.9-million tonnes grading 3.6 g/t for 1.1-million ounces of gold.

Resolute aims to re-establish an underground mine at the project.

A feasibility study has confirmed a viable development pathway. The study contemplates production of up to 1.2-million tonnes a year from longhole, open stope underground mining.

The stope will be started through a slot raise at one end of the ore drive and then mined by progressively firing the drill rings and retreating along strike.

Level designs will comprise:
• main level access, excavated 5.5 m wide × 5.5 m high with an arched profile;
• footwall drives, excavated 5.5 m wide × 5.5 m high;
• crosscuts and ore drives designed to fit longhole drills and loaders;
• stockpiles for storing stope ore ready for truck loading, placed every 150 m along the footwall drive; and
• a sump, placed in the main level access and linked to the lower levels through a drain hole.

The study proposes mining 100 000 tonnes a month of ore, with about 25 000 tonnes a month of waste providing a total rock movement of 125 000 t/m.

Ore processing will occur at the existing Bibiani processing plant.

A review of the current ore treatment plant at Bibiani and the results of testwork to date have been used to develop an effective processing flowsheet to achieve satisfactory recovery. Gold is predominantly fine and occurs along edges or cracks in pyrite and arsenopyrite sulphide minerals.

The process design produces a sulphide concentrate by flotation at a primary grind size of P80 106 μm. Concentrate is fine-ground to P80 25 μm before cyanidation. The flotation tails are also cyanide leached. Gold recovery is by carbon-in-leach (CIL).

Key process design parameters include:
• primary crushing to a P80 of 120 mm;
• milling, using the existing semiautogenous mill operation in single-stage closed circuit and producing a product size of P80 106 μm;
• flash flotation to a target mass pull of 2%;
• scavenger flotation, which, together with the flash flotation concentrate, recovers a total combined concentrate of 93% gold, 98% sulphides and 60% organic carbon into a concentrate mass that comprises 10% of new feed;
• concentrate regrind; and
• leaching of concentrate in a CIL circuit.

Gold production is expected to be maintained at an estimated 100 000 oz/y, which will sustain a five-year mine life on the initial ore reserve.

Potential Job Creation
Not stated.

Net Present Value/Internal Rate of Return
Not stated.

Capital Expenditure
Preproduction capital expenditure is estimated at $75-million.

Planned Start/End Date
The project has a short lead time of only nine months to production from the start of construction.

Latest Developments
None stated.

Key Contracts, Suppliers and Consultants
None stated.

Contact Details for Project Information
Resolute Mining, tel +61 8 9261 6100, fax +61 8 9322 7597 or email contact@rml.com.au