Tag Archives: Palabora Mining Company

M&R Cementation ready to make shaft sinking transition at Palabora copper mine

The sinking of the 1,200-m deep ventilation shaft at Palabora Copper, in South Africa, is proceeding apace, notwithstanding the COVID-19 shutdown and restrictions, contractor Murray & Roberts Cementation reports.

Work began on the 8.5 m diameter shaft early in 2019, with pre-sinking recently reaching a depth of 50 m and the changeover from pre-sink to main sink almost complete, according to Murray & Roberts Cementation Project Executive Mine Development, Graham Chamberlain.

Part of the development of Palabora Copper’s new LIFT II underground block cave mining area, the shaft will be developed to a final blind sink depth of 1,190 m, with a drop raise to its final depth. Completion is expected in the September quarter of 2022, Murray & Roberts Cementation says.

“We were required by the client and national lockdown regulations to pause our work schedule, but operations resumed as planned when restrictions were relaxed,” Chamberlain said. “The priority is to ensure that safe working conditions are maintained, and the COVID-19 infections are avoided.”

The project is using automated machinery at the shaft bottom, removing employees from high-risk contact areas. Modern, high-penetration rate hydraulic drills are deployed on robotic arms nested on the shaft sinking stage. This allows operators to conduct drilling at any position in the shaft without physically being in contact with the drills, the company says.

“We shorten our cycle times with the use of explosive delivery pods containing sensitised emulsion,” Chamberlain said. “Electronic systems deliver real-time data on blast holes numbers, volumes and pressures, improving blasting efficiency and quality.”

To reduce potential disruption from the intersection of poor ground conditions, Murray & Roberts Cementation takes the shaft lining to the bottom of the shaft during sinking. In the past, industry practice tended to carry this lining to about 20 m from the bottom.

“Our lining approach is applied with the use of a modified version of the traditional shuttering, and our specialised concrete mixes which we design for this specific purpose,” Chamberlain explained. “The mixes are prepared and delivered by our on-site batch plant.”

Chamberlain adds that the company’s focus on Zero Harm and a rigorous safety regime continues to deliver a high level of safety on the project.

MacLean breaks new ground in Africa mining sector

MacLean Engineering’s secondary breakers have been proving their worth in Africa, with a number of machines safely and effectively eliminating ore flow blockages and releasing trapped reserves above the draw point.

Built for the tough underground mining environment, these machines provide the solution to attacking high boulder hang-ups without endangering mine workers, according to MacLean.

One only needs to look at the Palabora copper mine, in South Africa, for proof of this, where three MacLean hang-up rigs have been working underground for over 15 years.

Palabora endorses MacLean’s commitment to promoting safety and productivity in the underground environment, through purpose-built, rugged and reliable mine vehicles, MacLean says. The SB8 and SB12 Secondary Breakers (993MR, previously) are part of MacLean’s Ore Flow suite, a leading ore recovery fleet in global underground hard-rock mining, and these rigs have brought down thousands of hang-ups at the operation, ensuring smooth running of both the mine and its mill, and a safe and sustained block cave operation, according to the company.

For lower hang-ups in a drawpoint, or oversize rocks on the ground too large for scoops to handle and too disruptive to get rid of with concussion blasting, the secondary reduction rig, the Blockholer, solves the problem and ensures production isn’t held up, MacLean says.

The past 24 months have been exciting for MacLean’s branch in Africa.

Petra Diamonds ordered a BH3 for its Koffiefontein diamond mine, in Free State Province, South Africa, with the company’s success showcasing increased safety used as a “proof point” to secure another order for a BH2 (pictured), according to MacLean, this time from the Kimberley Ekapa Mining joint venture, in the Northern Cape. Palabora has since placed an order for two secondary breakers for delivery in 2020.

“Both Koffiefontein and Kimberley mines echo the same message of improved safety, increased production, and long-term savings in infrastructure upkeep due to the inclusion of MacLean secondary breaking units in their mining cycle,” MacLean said.

The two-stage process of their conventional approach to reduce oversize and bring down hang-ups (drill with one machine and manually load explosives by hand) has now been combined into a single-stage process with the Blockholers. This process eliminates the need for manually loading explosives, thus improving operator safety, and reduces damage to the draw point infrastructure.

“In addition, these units are used by both mines as utility drills to drill off cubbies as well as eye bolt holes due to their mobility and self-sustaining drilling capabilities of diesel power,” MacLean explained. “This versatility makes the MacLean Blockholers an invaluable tool to the mines.”

Murray & Roberts Cementation to sink ventilation shaft at Palabora copper mine

Murray & Roberts Cementation says it has been awarded a contract by Palabora Mining Co for a 1,200 m deep ventilation shaft at its copper complex in Phalaborwa, Limpopo Province, South Africa.

The shaft, with a lined diameter of 8.5 m, will reach a final blind sink depth of 1,190 m before a drop raise takes it to its final depth, according to Braam Blom, Project Executive at Murray & Roberts Cementation.

“The duration of this project is expected to be just over three years,” Blom said. “After mobilisation, site establishment and surface civils have been completed, we expect to conduct pre-sinking until the end of 2019, with the use of our special shaft sinking gantry to a shaft depth of 65 m.”

A surface headgear and winder installation will then be constructed from January to March 2020. This will facilitate the slow sink to 200 m and the main sink until February 2022. Canadian shutter and lining methods will be employed, the company said. The team is expected to conduct shaft stripping by mid-April 2022 and to dis-establish the site by the end of May 2022, it said.

“There will be no stations or other excavations required, so this will help keep the team in a sinking cycle and optimise production levels,” Blom said. “We will run full calendar operations with 12 hour shifts and cycles of five day shifts, five night shifts and five shifts off.”

A relatively small labour force of 123 people is planned for steady main sinking conditions, with some sub-contractors conducting surface piling and civil works for the winder, headgear and other site construction. Shaft drilling itself will be done with two twin-boom Komatsu shaft drill rigs, and mucking by a Komatsu excavator with close to 1 t of loading capacity.

Blom said ground conditions were expected to be a challenge in some areas, as profiled from the cover and core drilling “However, we have various ways of reducing the risk and downtime during these intersections – such as keeping the shaft lining as close as possible to the shaft bottom,” he said.

Palabora operates a large block cave copper mine and smelter complex employing around 2,200 people, according to the company’s website. It has developed a $410 million underground mine with a production capacity of 30,000 t/d of ore.