Tag Archives: Fred Durand

Murray & Roberts Cementation and Palabora Mining celebrate last blast at new vent shaft

Explosives and blasting, Mine shafts and equipment, Mineral project development, Mining services, , ,

Leading underground mining contractor Murray & Roberts Cementation and its client Palabora Mining Company (PMC) have celebrated the last blast at the new ventilation shaft, which took its depth to a final 1,200 m below surface on January 9, 2024.

The 8.5-m diameter upcast vent shaft – which holed through to an already-developed return air way at depth – is vital to PMC’s Lift II project. Lift II will develop access to ore resources sufficient to extend the life of this copper mine beyond 2040. Murray & Roberts Cementation Senior Project Manager, Fred Durand, says a key achievement was the project’s fatality-free record, earned over more than a million hours worked.

“The achievement of a million fatality free hours – reached in November 2023 – is more than just a number,” Durand says. “It reflects the deep-rooted safety culture that has permeated every aspect of the project.”

The innovative sinking methods, used for the first time in South Africa, were also carefully focused on achieving zero harm. Murray & Roberts Cementation employed its Canadian shaft sinking methodology, adapted to what became called ‘the PMC way’. This method included a solution to poor ground conditions, where the sidewall of the shaft was closed up within 48 hours by means of the shaft concrete lining after every three metres of advance.

“Among the improvements that this facilitated was the removal of the hazardous work by rock drill operators at the shaft bottom, who would traditionally have to install temporary support,” Durand explains. “We also decided not to conduct concurrent work in the shaft, so there was no risk of danger to anyone below when work was carried out from the stage.”

Durand emphasised the close collaboration between Murray & Roberts Cementation and PMC to ensure the success and safety of the shaft sinking. The project was significant insofar as there were many lessons learnt to be taken forward into future projects, he says, further improving the safety record of shaft sinking practice.

“We are already looking ahead to two more important shaft sinking projects within the South African mining sector, where there is potential for certain of these learnings to be applied,” Durand says.

A veteran of over 15 shaft sinking projects around Africa during his career, Durand admits finding aspects of the PMC way initially quite unusual when he joined the project in 2022.

“Ultimately, though, we all want to deliver safe projects, so there are many brilliant ideas that we have proven on this project,” he says. “These strategies have been combined with the company’s leading mining and engineering expertise, and made us very excited about the future of shaft sinking and contract mining.”

To facilitate streamlined programming on the project, the work ran on continuous operations with two 12-hour shifts. This, he notes, improves on the usual eight-hour shift system, which requires three shift changes – each change taking up valuable project time. The two-shift system requires only a morning and evening change.

The vent shaft will replace the two existing vent shafts from the Lift I project, which are likely to be affected as they are in the Lift I zone of influence. In the final stages of the project, Murray & Roberts Cementation will strip out its services from the shaft, lift out the stage and dismantle the headgear. Final demobilisation of the company’s infrastructure will be carried out during the March quarter of 2024, according to Durand.

Murray & Roberts Cementation hits 1,000 m shaft sinking milestone at Palabora’s Lift II expansion project

Base metals, Explosives and blasting, Mine shafts and equipment, Mineral project development, Mining services, , , , ,

Leading underground mining contracting company, Murray & Roberts Cementation has achieved what it says is a remarkable milestone at the end of July 2023, successfully reaching the 1,000 metre mark on its contract to sink the 1,200 metre ventilation shaft at Palabora Mining Company’s Lift II expansion, in South Africa.

This significant feat stands as a testament to the company’s exceptional capabilities and dedication to safety, it says.

The Palabora Mining Company Lift II expansion project is a crucial endeavour for PMC, aimed at enhancing the efficiency and capacity of its operations. The 8.5-m-diameter ventilation shaft will serve the Lift II block cave and plays a pivotal role in the overall mining infrastructure.

Reaching a depth of 1,000 metres in the ventilation shaft is a major accomplishment, highlighting the expertise and commitment of Murray & Roberts Cementation in tackling complex mining projects, it says.

Fred Durand, Murray & Roberts Cementation’s Senior Project Manager, says one of the most remarkable aspects of this project is the unwavering focus on safety.

“Despite the immense challenges involved in underground mining and especially blind sinking, we have maintained an impeccable safety record throughout the Lift II expansion project,” he says. “The team’s relentless dedication to safety protocols and best practices resulted in an impressive milestone earlier this year of 574 consecutive days without a Lost Time Injury (LTI).”

He says that the achievement of this safety milestone showcases the company’s commitment to ensuring the wellbeing and safety of its workforce.

Durand concluded: “As the ventilation shaft project enters its final stages, the excitement and anticipation among all stakeholders, including PMC and Murray & Roberts Cementation, are palpable. The successful completion of this project will not only mark a significant engineering feat but will also have a profound impact on PMC’s mining capabilities.”

Murray & Roberts Cementation has aligned with the owner’s team to display technical excellence, professional management and passionate safety leadership from the day site establishment commenced in October 2019, according to Aidan Schoonbee, Senior Manager for PMC’s Lift II Construction, Concentrator and Vent Shaft.

Murray & Roberts Cementation shaft sinking alternative takes safety to a new level at PMC Lift 2

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The sinking of a 1,200 m ventilation shaft as part of the Palabora Mining Company (PMC) Lift 2 expansion in South Africa is proving to be a partnership success story, based on an unshakeable commitment to safety, according to Murray & Roberts Cementation.

PMC commissioned this new ventilation shaft – which measures 8.5 m in diameter – to service its Lift 2 block cave, awarding the project to Murray & Roberts Cementation in February 2019. Now in its final phases, the project has earned an impressive safety record; it has been fatality-free, and, last year, achieved 574 days without a Lost Time Injury (LTI), the contractor reports.

The Lift 2 project will extend mine life by more than 15 years. Originally an open-pit mine, the Palabora mine transitioned to underground block cave operations in the early 2000s when Lift 1 was commissioned. Back in February, Murray & Roberts Cementation outlined that it had recently celebrated the achievement of a major milestone – reaching the 800 m mark – at the project.

“Feasibility studies indicated that a blind sink was the optimal method, despite its higher cost and longer time frame,” Jas Malherbe, Murray & Roberts Cementation’s Project Manager, explained. “Ground conditions were among the reasons why raiseboring was not an option, as the side walls needed immediate support to prevent scaling.”

Traditionally, the shaft would be lined to within 12-18 m of the shaft bottom, with the sidewalls being temporarily supported with split sets and mesh. However, the difficult ground conditions led to high levels of scaling that made this practice unviable.

“With ground conditions being such a key challenge on the project, we responded in an innovative way by taking the shaft lining right down to the blasted face,” Malherbe says. “The shaft sinking methodology in this project is, therefore, based on the Canadian shaft sinking method pioneered by Murray & Roberts Cementation – but has been adapted to ‘the PMC way’. This has involved lining the shaft to within 1.5 m of the shaft bottom, after mucking out the waste.”

Murray & Roberts Cementation uses a specialised concrete mix for rapid setting and early strength which hardens to 3 MPa within four hours – and this would be in place for at least eight hours before blasting. This solution requires that the blast is conducted while the shutters are still in place – so the shutters are strengthened and a toe added that would better handle the blast. The exposed concrete above the shutter is able to withstand the blast, as it has already cured for 48 hours.

Malherbe explains that drilling is undertaken by two twin-boom electro-hydraulic jumbo drill rigs. These are slung down the shaft from surface and nested in the four-deck stage for drilling the shaft bottom, a procedure which is repeated for each 48 hour blast-to-blast cycle. Waste rock is lashed using an excavator with a 0.36 cu.m bucket, which is lowered from surface through the stage to shaft bottom.

After blasting, an excavator is used for loading rock from the shaft bottom, which is safer than the conventional cactus grab, according to Murray & Roberts Cementation. Ground conditions lend themselves to the generation of large rocks during blasting, which can be difficult to handle. These are broken up using an hydraulic breaker, which can be coupled to the excavator. An 11-t kibble transports the waste rock to surface.

The Lift 2 project will extend mine life by more than 15 years

“Lashing a shaft with an excavator is not a new idea, but it is usually a back-up method to the cactus grab,” Malherbe says. “In this project, we decided that the excavator would be the primary lashing method, to further enhance safety on site.”

Steps have also been taken towards automating the headgear, to avoid the safety hazards of manually hooking the kibble to tip out the waste rock. This includes the winding engine driver being able to use a camera to check for correct hooking.

“We also opted to use electric actuators in this project, rather than the traditional pneumatic and hydraulic cylinders on equipment such as the bank doors, swing chutes and tipping chutes,” Malherbe continues. “This has allowed us to mitigate the risks such as hearing loss from the noise of certain actuators, and contamination from oil leaks.”

According to Sechaba Letaba, PMC’s Package Manager on the project, PMC took a deliberate decision to prioritise safety in the sinking of this ventilation shaft.

“By taking the PMC way, we have accepted that the pace of sinking would have to be compromised,” Letaba says. “This has proved to be a positive approach, as we have an outstanding safety record on the project. This is in stark contrast to the history of shaft sinking, which would often claim lives and cause injuries. We are therefore very proud of what we have achieved to date.”

He highlights the pivotal roles played by Sam Ngidi, PMC Senior Manager Operation & Lift 2 Project, and Aidan Schoonbee, Senior Project Manager Construction – in driving the project and ensuring its success.

Fred Durand, Murray & Roberts Cementation’s Senior Project Manager, points out that unexpected challenges tend to have an impact on scheduling, so the strong relationship of trust with PMC was vital to solving any issues as they arose.

“Our approach has always been to work closely with customers on solutions, and to ensure they are regularly updated on progress,” Durand says. “As a team, for instance, we decided that the rock breaker was the right solution for the issue of oversized rocks, and it was accepted that this would have an impact on the cycle times.”

Similarly, encountering more challenging ground conditions than expected required a significant mindset change about how the team approached the project.

“With the supportive relationship between PMC and Murray & Roberts Cementation, we were able to agree on the necessary remedies and adjust the timeframe to suit our priority – which was safety,” he says.

Malherbe concludes that, for Murray & Roberts Cementation, the lessons learnt on this project have shown the industry a viable alternative method of shaft sinking that takes safety to a new level.