Tag Archives: South Deep

Gold Fields wins NERSA approval for South Deep solar power plant

Gold Fields says it has received the electricity generation licence approval from the National Energy Regulator of South Africa (NERSA) for the construction of a 40 MW solar power plant at its South Deep gold mine in the country.

The acting CEO of NERSA now has to authorise the licence, a decision that should be forthcoming over the next two weeks, the miner said. All the regulatory approvals to proceed with the project will then be in place.

Gold Fields will update its definitive costings and finalise all the required internal processes to commence the project as soon as possible. The company has stated previously that the solar plant has the potential to provide around 20% of South Deep’s average electricity consumption.

Nick Holland, Gold Fields CEO, said: “The solar power plant will increase the reliability and affordability of power supply to South Deep, ultimately enhancing the long-term sustainability of the mine.

“The approval of this licence sends a strong, positive message to mining companies and their investors, potentially leading to decisions being taken to sustain and grow mining operations in the country, especially in deep-level, underground, marginal mines. Enabling companies to generate their own power also gives Eskom room to address operational issues at its power plants.”

Gold Fields says its energy objectives are based on four pillars – energy must be reliable, available, cost-effective and clean – which promote a shift to self-generation using renewable energy sources. “We are fully committed to making our contribution towards net-zero emissions,” Holland says.

During 2020, Gold Fields successfully implemented solar and wind power plants, backed by battery storage, at two of its Australian mines, Agnew and Granny Smith, and committed to renewables at its other Australian mines, Gruyere and St Ives, as well as the Salares Norte project in Chile when it starts operations in 2023. All its other mines are also reviewing renewable energy options.

Since full commissioning of the Agnew microgrid, renewable electricity averages over 55% of total supply at the mine.

During 2020, renewable electricity averaged 8% for the Australia region and 3% of total group electricity, Gold Fields said. Once the South Deep project is commissioned, renewable’s contribution to the group total will rise to around 11%.

Holland concluded: “We expect our investment in renewable and low-carbon energy sources to contribute significantly to our carbon emission reductions over the next few years. Power from the South Deep solar plant will partially replace coal-fired electricity from Eskom, enabling us to significantly reduce our Scope 2 carbon emissions.”

Mines Rescue Services trials ‘world first’ mobile rescue winder at South Deep

Mines Rescue Services (MRS), a non-profit organisation, has reportedly carried out test work on a “world first” new mobile rescue winder that, it says, can reach a depth of 3 km underground.

MRS, on January 21, conducted the trial at Gold Fields’ South Deep gold mine, in Gauteng, South Africa, Engineering News reported. The winder can be used to bring employees to surface in the event that normal processes do not work, it said.

The winder was developed by MRS, in collaboration with Minerals Council South Africa members, the Department of Mineral Resources and Energy and Labour.

The testing involved lowering and raising the conveyance at a speed of 1.5 m/s, with a simulated load of six people, to a maximum depth of 3 km. The ability to reach such a depth is significant, MRS says, bearing in mind other rescue winders  could previously only go down to 1.6 km.

Maximising mining efficiency and productivity through control room best practice

As mines continue to increase their levels of mechanisation and automation, the importance of control rooms in providing situational awareness, and as the hub of operations management, is proportionally increasing, Tendayi V Mwayi*, Mobilaris MCE Sales and Business Development, Africa, at Epiroc’s Underground Rock Excavation division, says.

Control rooms collect, analyse and relay information necessary to monitor, measure and report performance, and control processes in mining operations. In its most modest form, a control ‘room’ can take the form of a desk in a quiet corner of a planning room equipped with a two-way radio and a desktop computer to record and report information from operations and relay information between operational units.

The more advanced control rooms, a couple of examples of which are showcased below, feature communications infrastructure; people and material tracking and visualisation tools; and planning, scheduling and optimisation systems that would closely rival the capabilities of those employed in the most advanced manufacturing and processing operations, Mwayi says.

In the West Rand Goldfields of South Africa, the 3 km-deep South Deep mine has constructed the South Deep Control Centre to “manage and monitor all operations (at its flagship Twin Shafts complex) from a central point”, Johan Sliep, Head of Technical and Production Intelligence Systems for Gold Fields Group Services, says. This is all tied to “improving the effectiveness and efficiency of operators through informed decision making”, he added. “This is where everything integrates.”

After one-and-a-half-years of construction, the ZAR2.5 million ($144,610) project is nearing completion.

In its final state, the state-of-the art control centre will provide overarching visualisation and control over all operations – including production, plant and logistics – centrally to deliver on South Deep’s strategic positioning as a highly efficient, safe, low cost, fully mechanised, world-class operation, Mwayi says.

The capabilities built into the South Deep control centre include mine planning, production scheduling, fixed plant management, safety management, production monitoring and control, backfill management, breakdown and planned maintenance management, processing and remote operations and analytics.

These systems rely on a fibreoptic backbone down the shaft and a blend of standard Wi-Fi and proprietary wireless mesh for communication of operational data from various sources. Additionally, an expansive network of leaky feeder supports voice communication over two-way radio in all areas of the vast underground mine.

Sliep reflected: “Every technology deployment has a business case associated unless it is a foundational requirement such as (communication) infrastructure, which on its own has a limited business case value.” Or, as Peter Burman, Program Manager – Mine Automation at Boliden Mine, puts it: “A communication infrastructure is nothing you should try to create a business case upon; that is stupid. A communication infrastructure is imperative to survival in today’s automated underground mines. It is like trying to create a business case for the sun or the air; it is simply a thing we need (in order) to survive.”

Tagging and tracking systems enable effective safety management from a central control room through real-time location tracking of personnel and equipment, which is often used to augment legacy clock-in, clock-out systems.

The improved situational awareness from systems such as Mobilaris Mining Intelligence reduces operational delays during normal operations, allows shafts to be cleared faster prior to blasting and reduces the duration of rescue missions when accidents occur by providing vital decision support to control room operators, Mwayi says.

Proximity detection systems together with the vehicle mounted collision avoidance systems, which original equipment manufacturers (OEMs) such as Epiroc now include as standard features on equipment, warn mine operators and pedestrians of potential person-to-vehicle or vehicle-to-vehicle interactions within a radius of up to 100 m. However, the situational awareness from Mobilaris Mining Intelligence extends the range of traffic awareness for control room operators, mine operators and pedestrians alike, providing the exact identity, location and direction of travel of people and vehicles in the entire mine, according to the company. This is achieved through the high-precision positioning and decision-support capabilities of Mobilaris Situational Awareness, Mobilaris Onboard and Mobilaris Pocket Mine, Mwayi said.

When quizzed about what is on his wish list for the South Deep Control Centre, Sliep suggests that “full operational control and management of operations” would be the ideal end goal for the mine.

What would that look like exactly and how could it be achieved?

Hans Wahlquist, VP Business Development & Strategic Product Management for Mobilaris MCE, explains: “Mobilaris Mining Intelligence is on the verge of launching a solution that would unlock the next level of control room capabilities in its innovative Mobilaris Event Automation platform which gives additional functionality to its already impressive Mobilaris Mining Intelligence product family.”

Wahlquist describes Mobilaris Event Automation as a tool to enable mine engineers to make full use of the information that comes from: location data of machines, equipment, materials and personnel; the status of work tasks in the shift plan; sensory data from various monitoring systems; machine data from a mixed fleet; and much more, by enabling engineers to create tailored automated actions themselves.

“With this feature, we give mines the power to take mine control to the next level,” Wahlquist says.

Event Automation, which is already deployed at Mobilaris’ first customers for the platform, would allow automated actions to be triggered when a defined set of causal events occur, for example, the switching on of a ventilation fan when threshold limits of carbon dioxide gas are detected, or the dispatch of a work order to a loader operator when a bolting activity is reported as completed.

“The beauty of the platform lies in the ability of mining personnel to ‘create’ the commands defining the cause and effect actions themselves,” Mwayi said.

Mwayi concluded: “Clearly, from the cases above, mining companies and OEMs that have embraced digital technology and evolved their operations; up-skilled, cross-skilled and re-organised their workforce enabling the use of technology that will inevitably be common place across all mines in the next three to five years, are achieving operational excellence in this industry 4.0 age.”

*This is an edited version of an article from Tendayi V Mwayi

Gold Fields looks for South Deep productivity boost with teleremote loading project

As part of plans to establish a sustainable footing for its South Deep mine in South Africa, Gold Fields is trialling teleremote loading in a project with automation specialist RCT.

Gold Fields’ problems at South Deep have been well documented, with the company, in 2018, launching a restructuring plan involving the reduction of mining areas, the lowering of overhead costs and an aim to use fewer machines more productively. This followed significant amounts of investment and continued underperformance at the mine.

It is the latter productivity goal that has led the company down the teleremote loading path.

In the June quarter of 2019, Gold Fields commenced non-line of site remote loading training at South Deep. Phase one of the project was to locate the operator control station in close proximity to the underground loading site, according to the company.

Martin Preece, Executive Vice-President Gold Fields South Africa, said soon after this training started, operators suggested an almost immediate move to “Phase 2” with an operator control station located in a recently built surface control centre in the main building at South Deep.

A surface automation chair was ordered from RCT, installed and commissioned in the centre and the company started the process of training up operators.

RCT’s ControlMaster® Automation and Control solutions enable companies to automate a single machine, to a fully autonomous fleet, while also offering step changes with teleremote solutions that allow operators to take control of machines from control centres, trailer cabins or mobile stations.

The interoperability of these systems allows for the seamless integration into any mine’s ecosystem, according to RCT.

Preece said Gold Fields’ approach with all technology is to trial with limited application, to develop and prove the technology, followed by rapid roll out.

“We are still in the first phase of the project and are learning and adapting our approach as we progress to perfect the system before broader application,” he said.

This first phase already has the company using one Sandvik LH514 LHD for teleremote loading operations in the long-hole stope loading areas of South Deep during shift changes. As Preece explained, the RCT technology allows for the LHD to tram between loading and dumping locations, and back autonomously with operator intervention only required when loading and tipping the LHD.

RCT has provided the on-board sensor technology, the network infrastructure in the working areas, the safety application and the surface operating chair – the Operation Automation Centre – located in the surface control centre, he said.

The control centre (pictured, left) was designed and established by South Deep and hosts the teleremote LHD operator automation centre, a teleremote rock breaker station, the operations control room, maintenance and production scheduling as well as business reporting functions.

This teleremote loading technology is, essentially, adding loaded tonnes to the operation where there previously was none, coming close to ticking off the ‘use of fewer machines more productively’ criteria Gold Fields previously set out in its turnaround plan. While not explicitly stated by the company, one would expect it helped South Deep achieve a 36% year-on-year boost in long hole stoping volumes mined, to 631,000 t, in 2019. Overall, Gold Fields said the mine produced 222,000 oz of attributable gold last year.

Teleremote rollout?

Preece said the technology it is trialling has been de-risked in the respect that it has been proven in many applications globally, and the company had very clear safety and commercial imperatives for it.

“The success of any change intervention is to ensure that the application becomes an enabler rather than a distraction for our frontline teams,” he said.

“We would like to believe we are close to operational deployment. Most of the initial challenges experienced with the technology itself have been addressed; the underground mining team is taking ownership by addressing the operating conditions. Furthermore, a second round of operator and maintenance training has been conducted.”

While the trial is currently limited to long-hole stope loading in between shift changes, in time, teleremote loading in development and destress areas of the mine could also be possible, Preece said. With plans to equip more machines in 2020, the results could get even better.

“The project business case is based on being able to continue loading over shift changes, so there is further upside when we add in the in-shift productivity gains as well as improvements to the development and destress mining cycles,” he said. “Our approach to expanding the rollout is that it must be self-funding – the value generated by the first deployment must fund the rollout of subsequent deployments.”

The company’s ultimate goal is to be able to operate LHDs continuously for 22 hours a day (the limit the machine can safely operate between refuelling, safety inspections and pre-start inspections, according to Preece), but there is more to achieving this aim than just rolling out teleremote LHDs.

“A pre-requisite for loading during shift changes is to be able to break big rocks in the tipping bins,” Preece said. This is where the successful deployment of teleremote rock breaking, operated from the same surface control centre as the remote LHDs, comes in.

Then there are the interactions with other equipment and, most importantly, people to consider.

“When operating the teleremote machine, the whole area has to be barricaded, isolated and protected by laser barriers, which, if breached, force the machine to stop automatically,” he said. “This will limit the application to areas which we can isolate.”

In areas where personnel are required to perform drilling, supporting, backfilling and other activities, the area cannot be completely isolated and the LHD cannot function optimally, according to Preece.

This might not be the case indefinitely.

“South Deep is exploring opportunities to schedule activities separately to enable broader application,” Preece said.

Similar technology deployed for trucks would be another future area of focus, according to Preece, while he said the mine was also in the early stages of trialling automated long-hole drilling in stopes over shift changes.

South Deep is one of the deepest mines in the world, going to depths close to 3,000 m below surface. Even so, depth is not one of the main business drivers for the increased take up of teleremote operations, according to Preece.

“Safety benefits and the time a machine can effectively be utilised make up for the bulk of the return on investment,” he said. “The challenge with deeper mines are on the support side; if the network infrastructure is in place, it should be the same for shallow or deep mines. For deeper mines, it will take longer to get maintenance and instrumentation support to the machine if something goes wrong.”

Still, could full automation be on the cards?

“Yes! Loading activity remains the most challenging given the variable fragmentation of material,” Preece said. “Operators still need to perform the loading and tipping activities.”

These teleremote and automation projects, on top of personnel and mobile equipment tracking systems previously mentioned in the company’s 2019 annual report, bode well for future automation take up at South Deep, as well as the success of Gold Fields’ turnaround plan for the asset.