African gold miner and explorer Randgold Resources is a ‘pro’ at developing large-scale gold mines in the remotest African regions. Its latest project, Kibali, fits this profile perfectly, writes Laura Cornish.
Not only is Randgold Resources capable of finding large-scale gold deposits in Africa, but has developed and perfected its skill of converting the properties into profitable operating gold entities in the face of ‘typical’ African continent challenges. “No other mining company has achieved the delivery of so many new mines in Africa,” says Randgold Resources CEO, Mark Bristow.
The Kibali project is the company’s latest venture (together with AngloGold Ashanti) and remains on track to start producing at the end of 2013, and reach full production the year after. With a 10 Moz mineral reserve (and 18 Moz resource), the project represents one of the largest undeveloped gold deposits in Africa. It is set to deliver an average of 600 000 ozpa for the first 11 years with an average grade of 4.2 g/t. The project has a 17-year lifespan, although ongoing exploration is expected to see this extend substantially.
Situated in the Democratic Republic of the Congo (DRC), Kibali will include an integrated underground and opencast mine, a twin-circuit sulphide and oxide plant with a run-of-mine (ROM) throughput of 6 Mtpa. The project covers an area of 1 836 km² in the Moto gold fields in the north east of the DRC and is located some 560 km north-east of the city of Kisangani and 150 km west of the Ugandan border town of Arua.
Once in production, the Kibali project is expected to contribute about 20% towards Randgold Resources’ entire portfolio. This is significant considering it owns just 45% of the project, with AngloGold owning another 45% and the Congolese parastatal, Sokimo owning the remaining 10%. “We have a long-term working relationship with AngloGold and like sharing the commercial risk. Both companies have very different DNAs and as such bring different strengths to the venture. Our strength of course lies specifically in successfully managing technical and political risks,” says Bristow.
The project’s development is broken down into two phases. The Phase 1 capital programme is estimated at US$920 million (R8.34 billion) (before escalation provisions and contingencies) and will cover the metallurgical facility, a hydropower station and back-up thermal power facility, construction of the tailings storage facility, relocation of villages, opencast mining and all shared infrastructure. This will run over a two-year period.
The Phase 2 capital programme is estimated at US$650 million (before escalation provisions and contingencies), which will run concurrently with Phase 1 but will extend over four years, is focused primarily on the underground development and includes a twin decline and vertical shaft system as well as three hydropower stations. This is expected to bring the underground into first production by the end of 2014, with steady state production targeted for the end of 2015.
Randgold Resources is considered an expert in interpreting and understanding the nature and geology of gold deposits in Africa, “which are generally high grade ore bodies, with narrow seams,” says Bristow, adding that Kibali is no exception.
The project is on track to deliver its first gold from the plant at the end of 2013 and will ramp up to deliver about 550 000 oz of gold in 2014.
The underground mine will be accessed via a twin decline system (men and material and rock hoisting) as well as a 2.8 Mtpa, 770 m deep, 8 m diameter production vertical shaft. Mining methods will be a combination of long-hole open stoping, longitudinal (along strike) and transverse (multiple stope accesses), depending on the height of the stope, which varies between 25 and 40 m. The mine will employ about 3 500 people once the underground mine is operational and at nameplate capacity, of which 90% will be Congolese nationals.
“The plan is to mine our opencast reserves while simultaneously developing underground. This will ensure we start generating cash early. Because our opencast reserves are substantial, there will be an overlap of production from surface and underground.”
On surface, Kibali will comprise six individual pits, which will be mined over a 10-year period, with the potential for another two. Even though underground material is higher in grade, the intention is to convert more opencast reserves. Kibali will, however, be a long life underground mine.
“We have already started with additional resource conversion and believe there is huge upside potential. As such, our exploration strategy is threefold. We want to extend our current underground ore bodies (by about 1 Moz by March/April 2013), which appear to continue their down-dip nature; convert some of our 8 Moz inventory (including near-mine targets) to resource category and continue with our Greenfields exploration,” Bristow outlines.
The metallurgical plant
Even though Kibali will be a 6 Mtpa operation, initially, the process plant’s design capacity is 7.2 Mtpa, accommodating future possible expansions. All ancillary project infrastructure has been designed and built to accommodate expansions down the line as well.
The plant incorporates a carbon-in-leach circuit stream to process the oxides and a flotation circuit stream for the sulphides. Upfront commissioning and early stage production using softer, ‘easier-to- process’ oxide material will ensure a smooth start-up process, says Bristow. Both streams are capable of processing hard ore (sulphide material), because the surface oxide material will deplete first. The overall plant recovery rate is expected to be about 87.8%.
“This is the first Randgold operation to incorporate a full flotation circuit, which is something we are particularly proud of. It shows our ability to implement appropriate and advanced mining technologies and improve on previous mine designs.”
The company also does not believe in the traditional EPCM model. “We have an extensive owners’ team on-site, which works closely with our appointed engineers and contractors.” There are currently about 5 000 people on-site as construction momentum continues to advance.
As a strategy to combat the insufficient, erratic and unreliable power supply in the DRC, Randgold Resources is investing in the construction of four hydropower stations and the upgrade of a fifth, all based in close proximity to the mine.
During the rainy seasons, the hydropower stations will provide 47 MW of power to the project, which will drop to 40 MW in the dry season when diesel-driven thermal power generators will make up the supply difference.
Once completed, the upgraded Nzoro 1 power station (an old Belgium power station) will supply 1 MW of power to the local community. The combined target output for Nzoro 2, Azambi, Ambarau and Sessenge equates to 47 MW in total.
A critical component of the Kibali project is the 18 000 strong community, which until recently, was located above the mine’s resource.
“We have had to relocate the entire town, which comprised 14 separate villages. This involved building new homes, and relocating 3 000 graves, 14 schools, 17 churches, five clinics, an entire catholic church complex, markets, farms, a nunnery and a monastery. Village relocation may be typical practice in the mining sector, but rarely on this scale.”
To date, a total of 1 407 families (from eight villages) have been resettled and a total of 1 780 houses completed. 50 000 bricks a day are being used to build nearly 60 houses a week.
The current status
The 180 km road linking the mine to the Ugandan border was upgraded, along with 14 bridges to accommodate the significant levels of traffic required to transport all equipment items to site. “The mills alone required 57 t truck payloads. We are clearing up to 200 trucks on the border post every week.”
“Looking forwards, our target for this quarter is to start the pre-sink of the vertical shaft (construction of the declines has already commenced),” Bristow continues.
Kibali has advanced its status from ‘manufacture and procure’ to ‘erect’. All major items, including the mill shells and gearboxes, CIL tanks, 70% of structural steel, 13 gensets (of 36) on-site, primary crushers, secondary crushers, the kiln, interstage screens, overhead cranes, discharge screens, fuel farm tanks, are already on-site. “We are pouring about 200 m3 of concrete a day.”
The girth gears, elution columns, agitators, remaining gensets, 30% of piping, apron feeders, hydro equipment turbines, heat exchangers, electro-winning cells, conveyor idlers, cabling, electrical and instrumentation equipment and cyclones are all en-route.
Sidebar: The key to working in Africa
“We have been operating since 1995 in sub-Saharan Africa, and while every country is different, there are always similarities.. But governments have grown to recognise us and see the benefits our mines bring to their countries. It is important to be completely transparent.”
Metallurgical plant/tailings storage facility/hydropower plants/infrastructure:
- GPS (Group 5 Civils, Protech, Safricas)
- Group 5 Projects (SA)
- Weldcon (from Kenya)
- M&T (from DRC and RSA)
- DRA Mineral Projects (SA)
- Polysius (German)
- Traminco (Congolese)
- Civicon (Uganda)
- Bell (SA)
- KMS (French)
- Shaft Sinkers (SA)
- Byrnecut (Australian)
Relocation assistance programme:
- Kingdom Building Company (Congolese)
- Optimum Consult (Congolese)
- Inter Orientale Builders(Congolese)
- ADCR (Congolese)
- Kibali Construction (Congolese)
- Chez Bibas (Congolese)
- SCBC (Congolese)
- MBOSAC (Congolese)
- El Shaddai Construction (Congolese)
- Ethagec SPRL (Congolese)
- Algro Consult (Congolese)
- Plumbcore (RSA expats)
- EFB (Congolese)
- Kokwo Construction (Congolese)
- FFK/Tradecorp – Kenya
- ETS (Congolese)
Drilling / exploration:
- GeoSearch (Congolese)