Compiled by Sharyn Macnamara
Industry learnings and new technology sure to have a positive effect in averting FOG injuries and tragedy in mining in South Africa were shared for the good of all in the Fall of Ground Action Plan (FOGAP) Day of Learning that took place in March in Johannesburg.
The ‘Day of Learning’ concept has been driven by the Minerals Council of South Africa and industry associations and stakeholders for a while now as one of the efforts to help reach the end goal of Zero Harm in an always dangerous, ever-changing and people-centric industry impacted by nature and human fallibility every day. Mining Houses shared some of the leading practices and latest solutions that look to help manage the risk in FOG (Falls of Ground).
The stats and the facts
Within a month, by the end of March 2023, the industry reported four FOG-related fatalities compared to a record-low of six FOG-related deaths in the whole of 2022. Japie Fullard, chair of the Minerals Council’s CEO Zero Harm Forum, said in his keynote address at the Day of Learning, “However, the industry must assess whether the FOGAP could have prevented the latest fatalities after contributing to a 70% reduction in deaths last year. For example, the industry’s focus is predominantly on netting and bolting hanging walls, but there are high-potential risk incidents that come from sidewalls collapsing. It’s something for teams to consider.
“Our FOGAP framework is sound. We must implement it, measure it and continuously review it. FOGAP must be relentlessly implemented and run its course.” Technology plays a vital role in enabling miners to assess their work environment, identify risks and resolve them – and over and above this, it adds to safe efficiencies assisting miners to fast-track target reaching, which is sometimes something that causes the workforce to cut dangerous corners in the first place.
Fullard noted that the one thing that cannot be removed from the mining equation completely is the human-fallibility factor – adding risk and the unknown to an already complex and dynamic environment. The mining industry has spent hundreds of millions of rands in technology to try to remove employees from high-risk working areas, using roof bolters, scalers, underground illumination, and, at some operations, costly permanent netting – all core to FOGAP. Ever-evolving tech, however, can assist on many levels in improving safety and with this in mind, the industry shared three areas of innovation.
Hydro-drilling lessons from Implats
Remote in-stope drilling using hydro power is undergoing a trial at Impala Rustenburg, using the Isidingo Drill as an integral part of the assessment to find an alternative to compressed air. One immediate win is the first woman employed at Impala Rustenburg as a rock drill operator (RDO), says Kabelo Lefifi, Head: Best Practice at Impala. “It’s a great milestone for us.”
The six-month trial by two suppliers at two half-levels with 17 crews at different shafts was due to end in June 2023 (at the time of writing), but already the results were encouraging in March as Impala continued to explore ways to remove operators from the face. Remote in-stope drilling using a rig, stations/keeps the RDO under netting. The Impala Rustenburg mine layouts and more remote working spaces meant there was insufficient compressed air for conventional drills, so the company started searching for alternative drilling technology in 2020. “This is not a new technology. It has been around for some time, but in our business, it is new. To be successful, the technology must be accepted by operators who are using it daily in the workplace,” said Lefifi.
Impala set 25 key performance metrics, including:
1. Remote drilling and a safer environment for RDOs: a move from conventional handheld to rig drilling, 1m from the face versus 2m and now under a net, respectively.
2. Noise reduction to comply with the Mine Health and Safety Act – Impala undergoes the process change, more benefits in hydro versus conventional compressed air are experienced.
3. Improved drilling speed and increased penetration rates.
4. Drilling accuracy and improved drilling discipline.
Benefits include improved safety with minimised human exposure to high-risk zones with the removal of RDOs from the face; less physical effort is required and the drill is easy to operate (allowing for women RDOs, current RDOs are aging and with this new technology there is ease of handling); noise and vibration exposure is reduced; reduction in water and energy usage allows for higher ESG compliance and a reduced footprint; non-polluting and aligned with Impala’s sustainability goals; increased production and lower all-in sustaining costs per ton mined; precision drilling improves blast efficiency and advance rates increasing yields.The solution replaces inefficient, expensive and slow compressed air with proven water hydraulics .
Quick wins in illumination for Sibanye-Stillwater
“Every day we send people down into an ever-changing, hazardous environment,” said Eric Cilliers, engineering manager at Sibanye. “For us as leaders to enable our employees to identify hazards to the best of their ability is the way forward. This will assist with operational excellence and will become industry best practice.”
Sibanye has met with quick wins in illuminating underground areas used by trackless mobile machinery in development ends, travelling ways and cross cuts, which can use a higher voltage than is safe in a conventional stope, explained Cilliers. The immediate limitation of low-voltage LED strips is that their performance is reduced by the length of face as well as distance to an electrical outlet. Sibanye is working in partnership with suppliers to raise the voltage of LED cables.
Adwoa Issaka of the Minerals Council’s MOSH FOG Team said in workfaces and ancillary excavations, employees rely only on their cap lamps for illumination. Cap lamps are inadequate for proper rockfall hazard identification. In 2021, when the FOGAP was adopted by the CEO Zero Harm Forum, workface visibility was identified as a quick-win project. MOSH approved Improved Underground Workface Visibility Leading Practice in 2022.
Sibanye-Stillwater intends on making underground illumination and improved underground workface visibility one of their minimum standards.
Advance warning for Anglo American with NanoRadar FOG system
Anglo American is working with Australia’s Geobotica on a radar system as small as a mobile phone to use underground and monitor rock movements. Developing the system as part of its Elimination of Fatalities work, the intention is to give Anglo American employees advance warning of changes and potential rockfalls or bursts.
The NanoRadar system has moved from the building of the prototype in the second half of 2022, to laboratory testing in the first quarter of 2023, to deployment at an active underground platinum mine in South Africa between April and August this year, said Dewaldt van Rooyen, a geotechnical specialist at Anglo American.
“This device is millimetre precise. It can measure a person’s heartbeat,” he said. The system essentially compresses the large radar systems used to monitor slopes in open pit mines and can be used to scan and check for movement in hanging walls, sidewalls and working faces, ignoring the movement of people and blast-on nets with apertures of 85mm.
The system is robust and waterproof; comes with a long battery life; and has no moving parts and no buttons that can accidentally be pushed. It also covers a large area, unlike existing systems that are narrowly focused and is set up using software, eliminating the need for calibration. It communicates its data easily through Bluetooth or Wi-Fi, and data can be delivered in/op real time to multiple users.
The system collects data, which geotechnical staff can use for analysis of the rock mass – how it behaves, trigger points for failures, and what happens during rockfalls. In future, the NanoRadar could be fed into the FOGAP programme as part of the mining industry’s initiative to eliminate fatalities and injuries from falls of ground, Van Rooyen said.
Underground NanoRadar system critical risk test accomplishments include: sync connectivity and communication; data recording; Deploying Stick/Pole concept; no button functionalities; zero false alarm rate; lights visible; rock scanning; equipment and people removal algorithm; H2O has very low influence; and scan through blast on mesh. Concern to be investigated: sensitivity to vibration – any movement must be less than 0.5mm (a face handheld driller causes 0.4mm movement).
Machines do the dangerous work at Palabora Mining Company
Palabora Mining Company has entirely mechanised the scaling, support drilling and installation, and shotcrete spraying operations at its copper mine. No work is done by people beyond the last line of supported hanging walls and sidewalls because of the technology deployed underground, said Thokozani Mtshali, superintendent Geotechnical at the company, “One rig does almost everything – scaling of the hanging and side walls, drilling of holes, supporting and blasting the face. We have removed people from the face.” Even the marking of support is done by a miner standing under the supported area by using a long pole.
In conclusion, removing people from the face is first prize, as Fullard said, in his opening statement, “It’s important to use technology because we cannot only rely on human behaviour. The most difficult thing to do is to always control human behaviour. How do we make sure we keep our people aligned, safe and alive every single day? Zero harm is achievable. We’ve shown that. We must keep on doing what we are doing with what we know is working. Collaboration is critical because we cannot do it alone as just the employers.” A big part of collaboration is information sharing.
Source: Minerals Council South Africa
What is FOGAP:
The Minerals Council implements the FOG Action Plan (FOGAP) project in partnership with:
- Association of Mine Managers of South Africa (AMMSA)
- South African Collieries Managers (SACMA)
- South African National Institute of Rock Engineering (SANIRE)
- Organised labour
- The regulator (DMRE)
- Research institutions
- Addresses FOG fatalities
- CEO endorsed
- R46-million budget over five years
- Owned by AMMSA, SACMA, SANIRE
- Oversight by RETC
- Holistic – six pillars
- Adoption of leading practices
- Research and Development
- Skills development
- Policy issues
- Achieving zero harm production
- Implementation and monitoring
FOGAP framework is delivering:
- In 2022, there were 6 FOG-related fatalities, a 70% reduction from the 20 deaths the year before.
- The number of FOG fatalities had fallen to an average of 24 a year in the 2016-2020 five-year period from an average of 111 a year in 2001-2005, a 78% improvement.
- Some of the key interventions were:
- The implementation of entry examinations and actively making working areas safe daily from 2009.
- In 2012, the ‘netting and bolting’ of tunnel roofs and walls was introduced, and the use of steel nets has become a common feature in South Africa’s deep-level mines.
- Impact of planning and modelling of seismicity risks in certain work areas.
- In-stope lighting/improved illumination.