While Anglo American Platinum’s (Amplats) large-scale Mogalakwena open pit mine may hold ‘first place’ on the global PGM production podium, its greater potential has yet to be reached.
Through intensive focus on ensuring all areas of the operation are streamlined and optimised – which more recently included a mining contractor changeover at one of the mine’s four open pits – it is set to continue over-achieving year-on-year. LAURA CORNISH met with the leadership team on site to find out more.
Situated 30 km north-west of Mokopane town in Limpopo on the Northern Limb of the Bushveld Complex, the Mogalakwena mine, established in 1993, operates under a mining right covering 137 km² with four of its five existing open pits delivering 100% of its production.
Together they contribute towards the production of a palladium-rich (45%) platinum group metals (PGM) concentrate from three concentrators – the on-mine North and South concentrators as well as through the use of Messina mine’s (which is on care and maintenance) Baobab concentrator.
Building on excellence
A steady focus on optimisation initiatives across the complex has seen Mogalakwena steadily improve its production from 305 000 oz of platinum in 2012 to 496 000 oz in 2018 – or from 721 000 PGM ounces to 1.17 Moz. The 2018 production level alone equates to a 7% increase on the previous 2017 year.
While these numbers are impressive for what is already such a massive open pit operation, and in fact the largest open-pit PGM mine in the world, this is by no means the end of the mine’s potential.
Amplats is targeting another significant increase in production for 2019, and estimates closing the year on just over 511 000 oz of platinum or a total of 1.22 Moz of PGMs. The result will likely see a further increase on the R3.2 billion economic free cash flow from the previous year while maintaining a >40% cash operating margin.
“Despite such an enormous operation, safety remains one of Mogalakwena’s top priorities,” says load and haul section manager Jerry Mothibe. And the numbers (at the time of going to print) reflect this statement to be true:
- North concentrator: 489 days LTI-free
- South concentrator: 315 days LTI-free
- Mining – 236 days LTI-free
- Operation – 8 million fatality free shifts since 2012
- No fatality since 2010
For now, the majority of the mine’s production is generated using 300 t Komatsu 930Es from the adjacent Central, North and South pits which cover a combined distance of 6.5 km (in length), average about 350 m in depth and together have an average grade of 3.34 g/t (as reported in Amplats’ Q2 production report).
At a depth of 176 m and an average historical grade of greater than the three combined pits, the six-year old fourth and smaller Zwartfontein pit contributes to overall production as well. Although by far the youngest pit, it already has an interesting story to tell.
Zwartfontein’s stellar transition
Because the Zwartfontein pit is considerably smaller than its sister Central, North and South pits, its daily performance relies on mining equipment suited to its size and production requirements.
With an in-house fleet dedicated to moving just over 300 t per truck load across its three main pits, Mogalakwena relies on the resources and technical skills set of a mining contractor.
With only six years of operating lifespan behind it, Zwartfontein’s journey – and particularly the last year and a half – could be considered an inspiring tale for any open pit mine.
Operated by Concor Opencast Mining (Concor), a subsidiary of black investment group Southern Palace, the full mining (load and haul) contract was taken over following the contract award in December 2017.
As a result of the process, Concor not only took over some of the previous contractor’s fleet, but also employed its entire workforce.
“The process required a seamless transition between old and new contractor with minimal disruptions to production and performance,” says Concor’s Zwartfontein contracts manager Donald Sisya.
While a contract transition of this nature is no easy feat, the open cast mining specialist was up for the challenge – having established a relationship on site thanks to previous work undertaken at the mine’s tailings storage facility.
The company has also created a reputation for successfully mining open pit, hard rock PGM operations.
“In combination with Concor’s technical skills set in this area, we were attracted to their cost competitive offer whichled to their appointment,” Mothibe adds.
Concor’s project at Zwartfontein specifically entails a three-year load and haul contract (as of 1 December 2017), during which time it is required to move 32.4 Mt of material – equating to around 12 Mt of ore and 20 Mt of waste material.
Sisya acknowledges that picking up on an existing contract has been no easy feat but to date the company’s change management structure has been a success with all +100 production personnel continuing to operate in their designated performance areas.
There have been however two major areas of significant change and subsequent improvement since the Concor project takeover.
“A revised shift hour structure has equated to enhanced productivity performance,” Sisya reveals.
A lot of time and money has also gone into upgrading the majority of the fleet which Concor quickly recognised was ageing and had also not been optimally maintained.
“We have phased out a large portion of our old equipment, and invested in the addition of three 130 t excavators (which will support the two existing machines), as well as 10 new 100 t trucks, or over 50% of the entire truck fleet,” Sisya reveals.
“The process has required unwavering commitment from Concor with the support of Mogalakwena and both fronts have delivered without exception. We have certain targets to meet this year – 900 000 tpm or 10.8 Mt over the 2019 year and we are confident of achieving this with the team, the fleet and our focus on delivering our required production performance.”
Ensuring a smooth transition between old and new contract with minimal interruption is definitely considered a success for Sisya, Concor and the team and one for the open cast contractor history books.
Investing in a new future
While streamlining the performance of the entire Mogalakwena operation, such as optimising performance of the Zwartfontein pit and also debottlenecking the North concentrator plant, is a daily priority and focus for the mine, its medium and long-term future is always on Amplats’ forward-thinking agenda.
“Mogalakwena’s future potential is still significant and we’re already evaluating options to tap into unlocking it further,” says mine manager Hendrik van Niekerk.
And while the steps to achieve this are not small-scale, they are also not pipe dreams but as the mine manager outlines, have been defined as a real, but longer term vision.
The mine has already made significant strides in achieving this. The Boikgantsho property (adjacent to Mogalakwena) for example was added to the complex’s mining right a few years back, extending the total strike length to 24 km.
Amplats is also exploring the possibility of transitioning Mogalakwena from an open cast mine to an underground mine.
Most exciting is the consideration to expand concentrator plant capacity. A pre-feasibility study commenced in 2018.
It remains underway and must consider the mine’s total future production design – including the merger of the Central, North and South pits into one super-pit, Van Niekerk explains.
“We must ensure consistent grades as the pits deepen and the stripping ratio increases, as well as the changeover from surface to underground.”
“In every decision we take, we must constantly ensure we are positioning the mine and the business correctly to return value to our shareholders, especially knowing we are competing for capital in a tight market.
“Our vision remains to continue producing the cheapest platinum ounce in the group,” he concludes.