Tag Archives: Kiaka

West African secures Lycopodium and Metso Outotec mills for Kiaka gold project

West African Resources Limited is heading towards construction at its 90%-owned Kiaka gold project in Burkina Faso, having registered strong funding interest, awarded an engineering, procurement and construction management (EPCM) contract and booked the mill package for the development.

Kiaka, an asset with 7.7 Moz of reserves and resources on its books, is the company’s second gold mine in the country on top of its operating Sanbrado asset.

WAF’s feasibility study, released in August 2022, outlined pre-production capital costs of $430 million and a 2.5-year pre-tax pay back at a $1,750/oz gold price for the project. Kiaka was expected to operate over an 18.5-year life of mine, producing, on average, 219,000 oz/y of gold (on a 100% basis).

West African Executive Chairman, Richard Hyde, said strong competitive bids from its debt finance process supported the company’s targeted debt of $300 million for the project.

In the meantime, WAF has signed a notice of award with Lycopodium based on the engineering company’s priced proposal for the EPCM of a new carbon-in-leach treatment plant for Kiaka. This award incorporated Lycopodium’s early commencement of the engineering and procurement portion of the contract to complete the engineering and tendering of the long-lead mill package.

Lycopodium was also the contractor on the Sanbrado construction project.

In line with this, Lycopodium and WAF have undertaken a competitive tender process for the supply and delivery of the SAG and ball mill package for Kiaka.

Following the evaluation of tenders, the company selected Metso Outotec to supply the 18 MW SAG mill and 9 MW ball mill. Metso Outotec also provided the SAG and ball mills at Sanbrado (construction of the comminution circuit, pictured). WAF has signed the order with Mesto Outotec, which contains a firm pricing and delivery schedule for the mill package components that fits well into the Kiaka construction schedule, it said.

The mining company says it has mobilised earthworks equipment to the Kiaka project site. The initial areas to be cleared include the permanent camp area and the process plant area. Access road upgrades are also planned to be undertaken during the current dry season.

The construction schedule for Kiaka remains on track, with major works expected to commence in the March quarter and first gold in 2025.

WAF says it also remains on target to meet 2022 production and cost guidance of 220,000-240,000 oz of gold produced at an all-in sustaining cost of less than $1,100/oz.

West African Resources spells out Kiaka gold mine potential

West African Resources has released the results of a feasibility study for its 90%-owned Kiaka gold project in Burkina Faso, heralding a potential open-pit mining operation that can support a processing plant throughput of 8.4 Mt/y.

Kiaka is 140 km southeast of Ouagadougou, and 45 km south of the company’s existing Sanbrado gold mine.

The Kiaka mining study is based on conventional open-pit mining methods, with run of mine ore being directly fed to the crushing circuit. Mining operations will use a combination of 140 t (Cat 6015) and 230 t (Cat 6020) hydraulic excavators matched to 95 t dump trucks (Cat 777s).

Drill and blast will be required from near surface, with the parameters selected based on the relatively hard rock mass qualities and the required selectivity for mining of the ore. Given the broad mineralised zone, a portion of the blasting will be able to be undertaken on 10-m benches with more selective zones blasted on 5-m benches, the company noted. As such a combination of top hammer (Sandvik Panterra DP1500) and downhole hammer (Sandvik Leopard DI650) capable blast hole rigs will be employed.

To achieve the targeted processing rate, a total material movement averaging 21 Mt/y is required for the first seven years of the production schedule. With the pit staging deferring waste movement, this increases to an average of 35 Mt/y for the next six years of production before reducing to an average of 15 Mt/y for the remainder of the mine life.

The production profile is suited to an initial fleet of 2 x 230 t excavators and 1 x 140 t excavator matched to 95-t class trucks. The fleet will increase to 3 x 230-t excavators with 2 x 140-t excavators for the higher production requirement. Further work to investigate bulk mining scenarios and optimise fleet selection will be conducted, with further refinement of the drill and blast parameters also being undertaken in conjunction with fleet optimisation.

Kiaka’s free-milling gold ore is intended to be processed through a conventional single stage gyratory crushing and semi-autogenous ball mill crusher (SABC) milling circuit followed by carbon-in-leach (CIL) processing. Extensive metallurgical test work indicates Kiaka will deliver life of mine gold recoveries of 90% at a nominal 100-micron grind size.

Following review of the option studies the company selected the following major equipment:

  • Primary gyratory crusher – a Metso Outotec Superior™ MKIII 54-75;
  • SAG mill – 18 MW; and
  • Ball mill – 9 MW

The crusher can achieve 8.4 Mt/y for the design blend at 65% availability. At a 70% loading, the throughput rate ranges from 9.2 Mt/y to 10.2 Mt/y on the design blend. The selected mills also have higher than typical design margin for the nameplate throughput rate with modelling conducted by OMC showing the selected comminution circuit is capable of a throughput of:

  • 8.4 Mt/y (1,050 t/h) for 100% fresh ore feed when the 80th percentile ore characteristics are used;
  • 9 Mt/y (1,125 t/h) for 100% fresh ore when modelled at the average (50th percentile) ore characteristics;
  • 14 Mt/y (1,750 t/h) for 100% oxide ore feed; and
  • 10 Mt/y (1,250 t/h) for a blended feed of 23% oxide and 77% fresh ore.

On a 100% basis, life of mine (18.5 years) production is scheduled to come in at 219,000 oz/y of gold.

West African Executive Chairman and CEO, Richard Hyde, said: “Kiaka will access power from the Burkina Faso grid predominantly supplied by low-carbon hydroelectric power from Ghana and the Ivory Coast with large Burkina Faso low-carbon solar projects planned to come online early in the mine life to supplement the grid.”

Hyde says WAF will investigate expanding Kiaka to plus-10 Mt/y through the addition of secondary crushing and debottlenecking the process circuit, as well as evaluating tenders for key major equipment received during the feasibility study, which had ranged widely in price and delivery lead times.

“There remains scope to reduce the capital expenditure and cost contingencies on this equipment, as well as shorten the lead times,” Hyde said. West African Resources is also looking at an owner-mining versus contractor (the current plan) study looking to lower mining costs and VAT working capital.

B2Gold weighs use of dual fuel haul trucks at Kiaka project

B2Gold’s strong growth path in Africa looks like continuing into future years after the company laid out preliminary plans to develop a mine in Burkina Faso that could use on-site hybrid power in addition to dual fuel haul trucks burning a mix of diesel fuel and LNG.

The Vancouver-based miner reported record total production in 2020 of 1.04 Moz of gold, with its Fekola (Mali) and Ojikoto (Namibia) mines contributing some 790,559 oz. It is guiding for 970,000- 1.03 Moz of gold in 2021.

In announcing these results, the company also provided an update on its Kiaka gold project in Burkina Faso.

This project, which B2Gold owns 81% of, currently hosts 4.25 Moz of indicated resources on a 100% basis at an average grade of 0.95 g/t Au. It also comes with 900,000 oz of inferred resources at 0.99 g/t.

The company is currently updating the existing feasibility study for the Kiaka project, reflecting, it says, the potential for improved economics resulting from lower fuel prices, alternative power options and a higher gold price.

A mineral resource model using additional drill results and revised model interpretations was completed in December, with the study set to leverage the new resource and several new concepts to reduce costs. Included among these new concepts is a plan to use a liquid natural gas (LNG) hybrid power plant combined with solar power, and dual fuel haul trucks that burn a mix of diesel fuel and LNG.

A larger processing plant size of 12 Mt/y is also being considered for this updated feasibility study, it said.

B2Gold expects to have an internal decision document completed by the end of March, with an updated feasibility study completed by the end of June.