Tag Archives: Carrapateena

Byrnecut to use six Sandvik 18-t-payload BEVs at OZ Minerals mines

Leading Australia-based contract miner Byrnecut is embracing the many benefits of battery-electric vehicles (BEVs) by purchasing six Sandvik battery-powered loaders with AutoMine® for use at OZ Minerals’ operations in South Australia.

Under a deal with Sandvik Mining and Rock Solutions, Byrnecut will take delivery of the LHDs in 2023 and 2024 for use at the Prominent Hill copper, gold and silver mine, south-west of Coober Pedy, and the Carrapateena copper and gold mine, north of Port Augusta. Byrnecut has been engaged by OZ Minerals to provide underground mining services at the mines and currently has a fleet of Sandvik LH621i loaders equipped with autonomous solutions operating on both sites.

We’re excited to be leading the way with battery-electric vehicles in Australia by putting these six Sandvik loaders into service over the next two years,” Max Woods, Asset Manager for Byrnecut, said. “Not only will the use of electric vehicles significantly improve the working environment underground, but it will also help our customers to work toward their emissions reduction goals – something that is increasingly important in the mining sector.”

Woods says the purchase of the electric loaders is part of Byrnecut’s commitment to explore and embrace new technologies that make its operations safer, more efficient and more sustainable.

“Eliminating emissions from loaders from the underground environment helps us create a better workplace, as does AutoMine technology that enables operators to work from comfortable remote control rooms,” he said.

Another major benefit to Byrnecut is the anticipated increased performance the new loaders could provide, Sandvik says.

The company worked closely with Sandvik prior to purchase to model various application scenarios, including both manual and automated operation.

“We’re expecting the loaders to provide greater throughput in both manual and automated modes while delivering a similar total cost of ownership per tonne delivered to their predecessors,” Woods says.

The new Sandvik loaders are also expected to bring major cost savings across their entire lifecycles, according to Woods. They are likely to require fewer replacement parts than their predecessors, and servicing is also more efficient and simpler.

Sandvik 18-t battery loaders are the most compact on the market, according to the OEM. The powerful electric motors, innovative electric driveline and the smaller tyres on the rear compared with the front, result in a small machine size, high payload with good visibility and unmatched speeds.

Battery machines produce no underground exhaust emissions and significantly less heat than traditional diesel engines, supporting the mines to reach sustainability targets, through reduced CO2 emissions.

Andrew Dawson, Business Line Manager for Load & Haul at Sandvik, praised Byrnecut for helping to pioneer the use of BEVs in Australia.

“The first Sandvik battery-electric loaders only began arriving in the country about a year ago, and the interest has been extremely strong,” he says. “We’re very pleased that Byrnecut and Oz Minerals see the benefits of this technology and is demonstrating it to the rest of the industry. We have always had an excellent working relationship with Byrnecut and look forward to cooperating with them throughout the roll-out and beyond.”

Zero Automotive overcoming barriers with BEV conversion offering

Zero Automotive is one of several Australia-based companies looking to supply the clean and green light utility vehicles the domestic hard-rock sector requires over the next decades to achieve crucial sustainability goals while retaining high productivity levels.

Thanks to the support of a significant copper-gold miner in Australia, its membership of the Electric Mine Consortium (EMC) and METS Ignited backing, the company finds itself in a strong position to deliver these machines against a backdrop of supply chain issues and ever-evolving safety and regulatory requirements.

“We’ve got commitments for six machines altogether and are in the process of offering our production version to the market,” Dan Taylor, Business Development Manager for Zero Automotive, says.

The first and second units are already running at OZ Minerals’ Carrapateena copper-gold mine in South Australia – Zero Automotive’s home state.

The first machine – a ZED70 Ti™ battery-electric light vehicle – was originally delivered to the mine at the back end of 2020 for testing. After successful trials, the company acquired this unit outright and, in early-2022, added a second Zero Automotive ZED70 Ti to enable its workforce to familiarise themselves with the capabilities and charging methodology that come with electric light utility vehicles.

Since then, the company has delivered a third ZED70 Ti conversion to Barminco, which is now on site at its client IGO Ltd’s Nova nickel-copper-cobalt operation in Western Australia. This vehicle is the first single cab conversion developed by Zero Automotive and will be deployed to site foremen to allow the mining contractor to gain a good understanding of its capabilities.

All three of these machines – and the three to follow – are based off battery-electric conversions of the Toyota LandCruiser 79 Series, a vehicle that has been part of the Australian mining landscape for many years.

The modular nature of the Zero Automotive platform enables its long-life battery energy system to be reused in multiple chassis, lowering the total lifecycle cost of the fleet as well as the cost of Scope 1 emissions, according to the company.

They also include dual AC-DC charging with the CCS Combo2 connection, which is becoming increasingly standardised in the mining space.

Data and feedback from the second OZ Minerals machine and the initial Barminco vehicle will be fed back into the EMC ecosystem under the Light and Auxiliary Equipment Working Group as part of the consortium’s continual improvement and knowledge sharing remit.

The EMC said of the consortium’s ongoing light and auxiliary equipment electrification ambitions: “Converting light and auxiliary vehicles as rapidly as possible to electric is key to the industry building the broader understanding and familiarity with electric equipment and infrastructure that will accelerate adoption across all aspects of operations.”

The EMC is a growing group of over 20 mining and service companies driven by the imperative to produce zero-emission products for their customers and meet mounting investor expectations. The objective of the EMC, backed by METS Ignited, is to accelerate progress toward the zero-carbon and zero-particulate mine.

The following three machines are also expected to be deployed to EMC members, with METS Ignited agreeing to provide some A$400,000 ($297,938) of funding towards the diesel-to-battery conversion projects outside of the vehicles already delivered to OZ Minerals.

“The key thing with all of these vehicle deployments is the ZED70 Ti being able to do the job the miners need to perform safely and reliably, getting the associated charging infrastructure right and working with key stakeholders on the change management process,” Dave Mitchell, founder and CEO of Zero Automotive, says. “Operators also need to get used to the power under the hood and how to maximise the battery re-charging capabilities when going down ramp.

“As a matter of course, we train up and educate the sites about the best way to utilise these vehicles,” he said.

To this point, the two prototype vehicles already operating out at Carrapateena have shown that they can work for a typical shift without requiring a re-charge and can then utilise the battery’s AC/DC-DC fast-charge option during shift changeover to enable another user to run the machine for the following shift.

The use of LTO (Lithium Titanate Oxide) battery chemistry and a 60-kWh battery capacity has been behind this performance. This electric motor can generate continuous power of 75 kW and peak power of 134 kW, plus 358 Nm of continuous torque. These values will be increased to 100 kW, 200 kW and 520 Nm (1,200 Nm peak) for the production version.

To this point, the power dimension has often been the main metric quoted with any battery-electric machine, but Taylor pointed out that safety and regulatory considerations were often the biggest barriers to overcome in terms of getting machines operating at underground mines – a hurdle that Zero Automotive has cleared.

“We were able to successfully commission our second ZED70 Ti for OZ Minerals within two days of the machine arriving on site,” he said. “A lot of people are putting out offerings for light utility vehicles, but the required risk analysis in terms of deploying a vehicle underground has not been successfully worked through. This is rightfully a high bar to clear.

“We address any safety or regulatory considerations during our design process – not when the machine is on site – to make sure that operators can start using them quickly.”

Mitchell adds: “The user case is what we are focused on. That has allowed us to scale our offering quickly and ensure our clients can start running the machine underground as soon as they have it on site.”

Zero Automotive is expecting to deploy the other three machines on its books to the same companies (OZ Minerals and Barminco), but the final two machines of the six to be delivered will be under a revised platform to the original ZED70 Ti.

“It will be a platform that is designed from the ground up that incorporates the desired features and learnings from the first conversions, but we will simplify it to reduce complexity, weight and cost,” Mitchell said. “We’re sticking with the same battery configuration – which has proven itself in terms of power, safety and longevity – but we’re adding some auxiliary power outputs and ensuring the machine is multi-purpose.”

The latter element is tied to the company’s medium-to-long-term ambitions, which include the potential to supply battery-electric machines specific to the extended range space too.

For now, Zero Automotive is focused on getting its machines underground at hard-rock operations, ensuring operators and mining companies start realising the productivity and emission benefits that come with these zero-emission conversions.

OZ Minerals turns down BHP’s A$25/share cash offer

OZ Minerals says it has rejected an unsolicited, conditional and non-binding indicative proposal from BHP to acquire all shares in the company for A$25/share ($17.3/share) in cash, valuing the company at an reported A$8.34 billion.

Having assessed this proposal, which represents a 13.1% premium to the volume weighted average price (VWAP) of OZ’s share price for the six months prior, the Board has unanimously determined that the offer significantly undervalues OZ Minerals and, as such, is not in the best interests of shareholders.

For its part, BHP points out in a separate press release that the consideration represents an “attractive premium” of 32.1% to OZ Minerals’ closing price of A$18.92/share on August 5 and 41.4% to OZ Minerals’ 30-day VWAP of A$17.67/share up to and including August 5.

OZ Minerals says the proposal is subject to a number of conditions including:

  • The completion of extensive financial, legal, technical and operational due diligence over a proposed six-week timeframe;
  • Various financial assumptions;
  • A unanimous recommendation of the OZ Minerals Board; and
  • Entry into a scheme implementation agreement subject to a range of conditions including no material adverse change, regulatory, shareholder and court approvals and conduct of business restrictions.

OZ Minerals says the Board has been advised by BHP that it has accumulated an interest in OZ Minerals shares via derivative instruments amounting to an interest of less than 5%.

OZ Minerals Managing Director and Chief Executive Officer, Andrew Cole, said: “We have a unique set of copper and nickel assets, all with strong long-term growth potential in quality locations. We are mining minerals that are in strong demand particularly for the global electrification and decarbonisation thematic and we have a long-life resource and reserve base. We do not consider the proposal from BHP sufficiently recognises these attributes.”

In coming to its decision, OZ Minerals says the Board considered that the proposal does not adequately compensate shareholders for:

  • The unique nature of OZ Minerals’ core business which represents a high-quality portfolio of copper and nickel assets, located in a Tier-1 mining jurisdiction with long mine lives, first quartile cost positioning and extensive strategic optionality;
  • The unique investment proposition which OZ Minerals provides as the only primary copper company in the ASX 100;
  • The low carbon intensity of OZ Minerals’ assets relative to its peers with a defined and market- leading plan for further decarbonisation to meet our target of net zero Scope 1 and 2 operational emissions by 2030;
  • The high-quality nature of OZ Minerals’ growth projects which include the West Musgrave project (final investment decision scheduled for H2 2022), the Carrapateena Block Cave and the Prominent Hill Extension which together are expected to generate significant production growth over the next five years;
  • The strong long-term outlook for both the copper and nickel markets underpinned by increasing geological scarcity, global electrification and accelerating decarbonisation, to which OZ Minerals is highly leveraged; and
  • The strong and consistent returns that the OZ Minerals management team has delivered with a total shareholder return of circa-145% over the past five years.

In addition to the above, OZ Minerals would deliver significant synergies and other benefits to BHP which the Board considers are not reflected in the value of BHP’s indicative proposal.

Among there are the operational synergies in both South Australia (between Olympic Dam, Carrapateena and Prominent Hill) and in Western Australia (between Nickel West and West Musgrave).

BHP says the cash offer it has made would deliver immediate value to OZ Minerals shareholders and de-risk any value which may (or may not) eventually be reflected in the company’s share price.

BHP CEO, Mike Henry, said: “Our proposal represents compelling value and certainty for OZ Minerals shareholders in the face of a deteriorating external environment and increased OZ Minerals operational- and growth-related funding challenges.

“We are disappointed that the Board of OZ Minerals has indicated that it is not willing to entertain our compelling offer or provide us with access to due diligence in relation to our proposal.”

ZERO Automotive commissions second battery-electric ZED70 Ti at Carrapateena

ZERO Automotive has delivered its second ZED70 Ti battery-electric conversion to OZ Minerals at Carrapateena in South Australia.

This vehicle was successfully commissioned within a day after a prior inspection and collaboration with the underground operations team, according to ZERO Automotive.

This latest addition to the OZ Minerals zero emissions fleet has dual AC/DC-DC charging with the CCS Combo2 connection, and an In-Vehicle Monitoring System. This provides the capability to monitor the battery status remotely, the company said.

The first ZED70 Ti became one of the first Australia-made street legal light electric vehicles to enter an underground mine after making a trip into the Tjati Decline at Carrapateena back in early 2021.

Howden tapping into South African deep mining experience

Mines are getting deeper with every year that passes – 30 m deeper, if industry reports are correct.

With increased depth, comes increased ventilation and cooling needs, a fact Howden knows well from its experience of working with the deepest mines in South Africa.

Originally founded in 1854 by James Howden in Scotland as a marine engineering firm, Howden made an entry into South Africa in the 1950s seeking to cater to the demands of the mining and power industries. By the 1960s, it was helping equip the country’s deep gold mines with all the ventilation and cooling products they needed to extract ore safely and productively from kilometres below surface.

“Initially mines used only ventilation as a method of cooling, but, as mining depth increased, mechanical refrigeration was required to counteract the increasing heat loads in mines,” Theuns Wasserman: Team Leader – Howden SA’s Mine Cooling and Compressor Division, told IM.

This saw many deep gold mines in South Africa install Freon™ centrifugal chillers above and below ground to provide the necessary cooling for personnel and machines underground.

While an improvement on the status quo, the heat rejection system for underground machines proved problematic, with the machines’ cooling capacity limited by the temperature and amount of reject air available, according to Wasserman. At the same time, the water quality of the mines resulted in high fouling on the piping shell and tube heat exchangers employed on these early centrifugal chillers.

This resulted in the machines being limited to cooled water temperatures of 6-8°C, he said.

To rectify this, mines started to pump chilled air from surface to underground. While this boosted cooling capacity, the required infrastructure took up space in the shaft and the process was both energy- and opex-intensive.

Battling these issues, mines looked to maximise the amount of cooled air that was sent underground via chilled water plants.

This led Howden to introduce ammonia-based screw chillers into South African mines, which were initially employed in series after the existing surface centrifugal chillers. This enabled a step change in the amount of cooling that could be transported to these deep underground gold mines, bringing the average water temperature sent from surface down from 6-8°C, to 1°C. Mines were able to use the same shaft pipe infrastructure, which many of them had in place, while drastically increasing the amount of cooling sent to deep levels.

Some 20 years after their introduction, Howden, as a leading market player in the space, developed the WRV 510 – a large block screw compressor with a 510 mm rotor. This was, at the time, one of the largest screw compressors on the market, which suited the module sizes of the chillers required for refrigerating these deep South African mines.

“That changed the game as mines could install a single refrigeration machine with 10-12 MW of capacity, instead of a fleet of chillers,” Wasserman said. “At the same time, ammonia, as a ‘green’ refrigerant, perfectly suited the screw compressor and plate heat exchanger combination.”

The considerations around the use of ammonia were formalised into mining-specific ammonia codes and safety standards that Howden was instrumental in devising. These have since been updated and incorporated into South African legislation.

Such success is evidenced by more than 350 MW of ammonia-based refrigeration capacity installed in the South African mining sector, believed to be the most of any country in the world.

But Howden’s South Africa-based innovations did not end there, with the company, in 1985, adding ice production plants on surface to its expanding mine cooling remit.

With surface and underground refrigeration options maximised or deemed too expensive, mines needed a new cooling solution to further expand mining into even deeper levels.

The first surface ice plant (example below) was installed by Howden in 1985 at the ERPM (East Rand Proprietary Mines) mine, east of Johannesburg, which had a final total cooling capacity of some 40 MW with an ice production capacity of 4,320 t/h.

The basis of operation saw ice produced on surface and sent down the mine shaft to an underground ice dam, with water from the ice dam then circulated to underground cooling stations or used as service water for drilling. The ice melt was then pumped back to surface.

The primary benefit of this ice system was the pumping cost reduction, being some 75-80% less than the opex associated with a system where chilled water is sent from surface. This is down to the inherent “cooling energy stored in the phase change of the water”, Wasserman said, explaining that 1 kg/s of ice has the same cooling capacity as 4.5-5 kg/s of chilled water.

With a “superior positional efficiency”, an underground water dam can be maintained at 2-5°C to enhance the thermal performance of underground air cooling stations – again, maximising the cooling capacity.

Another benefit of ice production plants that has specific relevance in South Africa – a country renowned for grid instability – is the ability for the system to be used as a method of thermal storage where ice is produced and accumulated in the underground ice dam and used during peak periods.

This latter advantage led to the development of an Eskom-backed industry collaboration project involving Howden looking at using an ice plant to reduce peak power demand, with test cases situated at Mponeng, the world’s deepest underground mine, and Moab Khotsong.

“We froze up a dam of water during the night (off-peak) and that water and ice melt was used during peak time as a mine cooling source,” Wasserman explained. “The baseload refrigeration plant was switched off during peak periods, taking the pressure off the grid.”

It led to the development of a full turnkey ice plant at Mponeng where Howden carried out works including the civils, electrical and mechanical equipment for a 12 MW, 120 t/h ice plant.

The latest addition to the primary cooling strategy for Mponeng mine that already included soft ice, chilled water from surface, surface bulk air coolers (BACs) and underground refrigeration systems, the ice plant was equipped with duplex stainless steel plate ice makers to deal with the high concentrations of dissolved salts and chlorides present in the mine water at the operation.

It is this wealth of experience in South Africa and a focus on solutions rather than solely products that continues to be translated on a global scale, as MG Mynhardt, Howden’s current Manager of Compressors in South Africa and soon-to-be Head of Global Mine Cooling, said.

With more mines going deeper and space within the shaft at a premium, it is easy to see such a solution having applications in other parts of the world, as Wasserman hinted at.

Mynhardt said: “Howden has been ‘exporting’ its South African deep mine cooling expertise for decades. Back in the 1990s, for instance, we provided a mine cooling solution for an underground gold mine in Nevada.

“One interesting technology utilised by some South African mines is thermal ice storage that is used for load shifting – where thermal energy is stored in large ice dams. The ice is produced during peak periods and utilised in peak periods,” he said. “Conventionally, refrigeration plants are sized for maximum ambient temperature, which might be experienced for three hours a day in the summer months. Yet, if you have a facility to store your cooling energy, you could reduce this capacity.”

The parallels with battery energy storage for replacing excess spinning reserves are obvious here.

“If you have an electricity tariff plan where you have a quite high peak power tariff that you want to shift to a cheaper off-peak tariff, these ice plant solutions could make for a strong business case,” he said. “The upfront capital for the plant could be offset against the lower operating costs.”

At the same time as these, BACs used at mines in South Africa for decades are gaining prominence across the globe.

The newest generation BACs have higher thermal efficiency than their predecessors, lower limits on the shaft air temperature and a reduced footprint when compared with traditional BAC construction types. They are also embedded with the cooling on demand (CoD) module within Howden’s Ventsim CONTROL platform where the temperature of the shaft collar air can be automatically modified to meet the demand below surface.

Howden supplied three of these new-generation BACs in the past year to customers in Brazil and Burkina Faso.

The company can also manufacture customised solutions to deal with challenging operating environments; a recent example being the “unique BAC” operating with ammonia chillers installed at the Carrapateena mine in South Australia for OZ Minerals.

“Without any water available, in Australia, Howden installed dry condensers with Howden ammonia-based compressors along with a closed-loop dry bulk air cooler,” Wasserman said of this installation. “These coolers were engineered for ultimate efficiency considering it was a ‘dry’ plant as opposed to an open-headed spray cooler installed in applications where water resources are available.”

And the company is currently trialling an “uptime” condition monitoring solution at the 8 MW surface BAC plant (pictured below) it designed and engineered for Fortuna Silver’s Yaramoko mine (previously Roxgold) in Burkina Faso.

This system, monitored from Howden’s Johannesburg facility, allows the company to advise of potential efficiency gains and maintenance issues to ensure the plant is run as optimally as possible. The BAC installation at Ero Copper’s Caraiba mining complex in Brazil has also been designed to use such functionality.

This isn’t to say Howden is only focused on projects outside of South Africa – far from it.

Its Total Mine Ventilation Solution (TMVS) platform is continuing to build sustainable, value-adding relationships, which saw the company carry out two ventilation on demand (VoD) feasibility studies in the country in 2021.

Just over the border in Zimbabwe, it is working on a project that could see VoD-enablement of an automated door at an underground mine, to allow it to open at different increments and supply the required quantity of cooled air based on specific vehicle demand.

Such technology developments – using existing available mine infrastructure and readily available data feeds – will become part and parcel of the Howden offering in the future.

Howden’s South Africa experience – learning how to engineer cooling solutions to deal with the poor water quality at its deep gold mines, how to make solutions as energy efficient as possible to circumvent grid issues and how to cater to some of the strictest air quality, temperature and occupational hygiene regulations across the globe – will continue to pay off for mines all over the world.

OZ Minerals set to deploy mDetect’s ‘space particle’ tailings dam safety device

Australian start-up, mDetect, a spin-out company from Swinburne University of Technology, is using particles from space, known as muons, to, it says, help mining companies detect weaknesses in dams that secure highly toxic mining waste by-products, making them environmentally safer.

The hazardous waste early warning system, using muon technology, will revolutionise how mining companies monitor the stability of tailings dams, thanks to mDetect’s technology and a A$1.5 million ($1.09 million) co-investment grant from the Federal Government’s Advanced Manufacturing Growth Centre (AMGC) Commercialisation Fund and partners to fast track its commercial production, the university says.

Swinburne University of Technology’s Vice-Chancellor Professor, Pascale Quester, said research and education into space technologies and their terrestrial applications have extraordinary potential for positive economic and social impact.

“Swinburne is focused on ensuring that the vital research we do has significant positive impact,” Quester says. “The important work of mDetect, led by Swinburne’s Professor Alan Duffy, is emblematic of Swinburne’s cutting-edge research and our ability to market innovative ideas. This is paving the way for successful research commercialisation that provides real solutions for industries.”

OZ Minerals, as a key industry partner, has been integral to the development of the technology. The miner is expected to deploy the device at its tailings dam at the Carrapateena operation in South Australia.

Myles Johnston, General Manager of OZ Minerals Carrapateena Province, said: “OZ Minerals recognises our responsibility to meaningfully contribute to regional economic and social wellbeing as stronger communities create value for all stakeholders. By ethically and responsibly exploring for and mining copper, we contribute to a low carbon future and economic wellbeing, which helps us achieve our purpose and contribute to a better future.

“We congratulate mDetect on being awarded the AMGC grant, and the team at Carrapateena is excited to be collaborating with mDetect on the development of a fully supported, flexible 3D muon monitoring system.”

Professor Duffy said: “Muons are heavier versions of electrons that are made when cosmic rays slam into atoms in Earth’s atmosphere. We have patented new detectors, that, combined with powerful artificial intelligence techniques, take an X-ray style scan through solid rock revealing different density structures.”

This patented technology can provide intelligence on the internal structures and substances of buildings, infrastructure, and subterranean and aquatic features, opening up a range of commercial opportunities for the construction and mining industries, Swinburne University says.

“Simply put, muon technology can look through rock to create underground images and detect abnormalities which will provide the early warning signs needed to prevent potential structural failures.”

mDetect will work with local manufacturing company Elgee Industries and Swinburne’s Factory of the Future to produce the muon devices at scale. Connecting these devices and turning detections into underground images will be undertaken by Swinburne’s Astronomy Data and Computing Services software development team.

OZ Minerals, Titeline investigate hydrogen-powered surface diamond drilling opportunities

OZ Minerals, in partnership with Titeline Drilling, has commenced a trial to test a hydrogen direct injection system to improve engine combustion efficiency for surface diamond drill rigs.

The system has the potential to reduce emissions of greenhouse gases and particulates, as well as improve fuel consumption, according to the company.

The news came out with the release of the company’s June quarter results, which saw a 22% quarter-on-quarter uplift in copper production following a strong performance from the company’s South Australian operations (Prominent Hill and Carrapateena).

In addition to the trial of hydrogen-powered surface drill rigs, OZ Minerals said the mining tri-alliance it has in place with Byrnecut and Sandvik – designed to identify and introduce smart and innovative ideas – had progressed during the quarter, with in-roads made on several associated projects.

Significant work was undertaken towards trialling the use of tele-remote loading of trucks, which has now been implemented in a key stope in July, it said.

OZ Minerals previously said it was working with Byrnecut and Sandvik to roll out Sandvik’s AutoMine® platform at its Prominent Hill copper-gold mine in South Australia. This followed a project between the two to implement an automation upgrade for a Sandvik DD422i development drill at the operation.

OZ Minerals wades into uncharted renewables territory at West Musgrave

You do not get much more remote than OZ Minerals’ West Musgrave copper-nickel project. Located in the Ngaanyatjarra Aboriginal Lands of central Western Australia, it is some 1,300 km northeast of Perth and 1,400 km northwest of Adelaide; near the intersection of the borders between Western Australia, South Australia and the Northern Territory. The nearest towns include the Indigenous Communities of Jameson (Mantamaru), 26 km north; Blackstone (Papulankutja), 50 km east; and Warburton (Milyirrtjarra), 110 km west.

This makes the company’s ambition of developing a mine able to produce circa-32,000 t/y of copper and around 26,000 t/y of nickel in concentrates that leverages 100% renewable generation and can conduct ‘zero carbon mining’ even bolder.

OZ Minerals is not taking this challenge on by itself. In addition to multiple consultants and engineering companies engaged in a feasibility study, the company has enlisted the help of ENGIE Impact, the consulting arm of multinational electric utility company ENGIE, to come up with a roadmap that could see it employ renewable technologies to reach its zero ambitions.

“We’re providing an understanding of how they could decarbonise the mine to achieve a net zero end game,” Joshua Martin, Senior Director, Sustainability Solutions APAC, told IM.

While ENGIE Impact is focused solely on the energy requirements side of the equation at West Musgrave, its input will prove crucial to the ultimate sustainability success at West Musgrave.

Having worked with others in the mining space such as Vale’s New Caledonia operations (recently sold to the Prony Resources New Caledonia consortium), Martin says OZ Minerals is being “pretty ambitious” when it comes to decarbonisation.

“Our job is to assess if the renewable base case stacks up for West Musgrave, create multiple decarbonisation pathways for their consideration and look at what technology should be adopted to achieve their overall aims,” he said.

This latter element is particularly important for an off-grid project like West Musgrave, which is unlikely to start producing until around mid-2025 should a positive investment decision follow the upcoming feasibility study.

While solar, wind and battery back-up are all likely to play a role in the power plans at West Musgrave – technologies that are frequently factored into hybrid projects looking to wean themselves off diesel or heavy fuel oil use – more emerging technologies are likely to be factored into a roadmap towards 100% renewable adoption.

“We are developing a series of roadmaps that factor in where we think technologies will be in the future,” Martin said. “These roadmaps come with a series of decision gates where the company will need to take one option at that point in time if they are to pursue that particular decarbonisation pathway.”

These roadmaps utilise ENGIE Impact’s consulting and engineering nous, as well as the consultancy’s PROSUMER software (screenshot below) that is used on any asset-level decarbonisation project roadmap, according to Martin.

“This software was specifically built for that purpose,” Martin said. “There is nothing on the market like this.”

Progress at PFS level

OZ Minerals’ December 2020 prefeasibility study update went some way to mapping out its decarbonisation ambition for West Musgrave, with a 50 MW Power Purchase Agreement that involved hybrid renewables (wind, solar, battery, plus diesel or gas).

The company said in this study: “Modelling has demonstrated that circa 70-80% renewables penetration can be achieved for the site, with the current modelled to be an optimised mix of wind, solar and diesel supported by a battery installation.”

OZ Minerals said there was considerable upside in power cost through matching plant power demand with the availability of renewable supply (load scheduling), haulage electrification to maximise the proportion of renewable energy used, and the continued improvement in the efficiency of renewable energy solutions.

ENGIE Impact’s view on hydrogen and electric haulage in the pit may be considered here, complemented by the preliminary results coming out of the Electric Mine Consortium, a collaborative mine electrification project OZ Minerals is taking part in with other miners such as Evolution Mining, South32, Gold Fields and IGO. And, on the non-electric pathway, ENGIE Impact’s opinion is being informed by a study it is undertaking in collaboration with Anglo American on developing a “hydrogen valley” in South Africa.

If OZ Minerals’ early technology views are anything to go by, it is willing to take some risk when it comes to adopting new technology.

The preliminary flowsheet in the prefeasibility study factored in a significant reduction in carbon emissions and power demand through the adoption of vertical roller mills (VRMs) as the grinding mill solution, and a flotation component that achieves metal recovery at a much coarser grind size than was previously considered in the design.

Loesche is working with OZ Minerals on the VRM side, and Woodgrove’s Direct Flotation Reactors got a shout out in the process flowsheet.

While mining at West Musgrave is modelled to be conventional drill, blast, load and haul, the haulage fleet will comprise up to 25, 220 t haul trucks, with optionality being maintained to allow for these trucks to be fully autonomous in the future, OZ Minerals said.

‘True’ zero miners

OZ Minerals is aware of the statement it would make to industry if it were to power all this technology from renewable sources.

“With a future focus on developing a roadmap to 100% renewable generation, and reducing dependency upon fossil fuels over time, West Musgrave will become one of the largest fully off-grid, renewable powered mines in the world,” it said in the updated PFS. “The solution would result in the avoidance of in excess of 220,000 tonnes per annum of carbon dioxide emissions compared to a fully diesel-powered operation.”

The company’s Hybrid Energy Plant at Carrapateena in South Australia, whose initial setup includes solar PV, battery storage, diesel generation and a micro-grid controller, will provide a test case for this. This is a “unique facility designed to host experiments on how various equipment and energy technologies interact on an operating mine site”, the company says.

Martin and ENGIE Impact agree OZ Minerals is one of many forward-thinking mining companies striving for zero operations with a serious decarbonisation plan.

“The mining projects we are working on are all looking to achieve ‘true’ net zero operations, factoring in no offsets,” he said. “Having said that, I wouldn’t say the use of offsets is an ‘easy out’ for these companies. They can form part of the decarbonisation equation when they have a specific purpose, for instance, in trying to support indigenous communities.”

These industry leaders would do well to communicate with each other on their renewable ambitions, according to Martin. Such collaboration can help them all achieve their goals collectively, as opposed to individually. The coming together of BHP, Rio Tinto, Vale, Roy Hill, Teck, Boliden and Thiess for the ‘Charge on Innovation Challenge’ is a good example of this, where the patrons are pooling resources to come up with workable solutions for faster charging of large surface electric mining trucks.

“In the Pilbara, for example, there is a real opportunity to create a decarbonisation masterplan that seeks to capitalise on economies of scale,” he said. “If all the companies work towards that end goal collaboratively, they could achieve it much faster and at a much lower cost than if they go it alone.”

When it comes to OZ Minerals, the miner is clearly open to collaboration, whether it be with ENGIE Impact on decarbonisation, The Electric Mine Consortium with its fellow miners, the recently opened Hybrid Energy Plant at Carrapateena, the EU-funded NEXGEN SIMS project to develop autonomous, carbon-neutral mining processes, or through its various crowd sourcing challenges.

ZED70 Ti battery-electric vehicle takes trip underground at OZ Minerals’ Carrapateena

The Zero Automotive ZED70 Ti has become one of the first Australia-made street legal light electric vehicles to enter an underground mine after making a trip into the Tjati Decline at OZ Minerals’ Carrapateena copper-gold operation in South Australia.

The vehicle made the trip in January and, according to OZ Minerals, managed over four complete round trips ‒ from the surface to the bottom of the mine and back ‒ without requiring a plug-in charge.

OZ Minerals said: “A big shout out to Zero Automotive for their hard work in developing such a great vehicle and commissioning it for underground use within two days!”

The Zero Automotive ZED70 Ti uses LTO chemistry and comes equipped with a specially selected battery housing, control systems and charging capability to endure the “hyper saline underground environment” at Carrapateena, OZ Minerals previously said.

OZ Minerals previously tested a Zero Automotive ZED70 battery-electric light vehicle on site at Carrapateena.

In June 2020, it also outlined a prefeasibility study on an expansion of Carrapateena that included a trial of electric light vehicles and establishment of a renewable energy hub.

Byrnecut adds Carrapateena to OZ Minerals underground contract mining portfolio

OZ Minerals Ltd has changed underground mining contractor at its Carrapateena copper-gold mine in South Australia following Downer EDI’s move to divest its mining services businesses to MACA.

The company has now signed an agreement with Byrnecut Australia for the delivery of underground mining and associated mining services at Carrapateena. The two companies know each other well, with Byrnecut already carrying out underground mining services at OZ Minerals’ Prominent Hill for the past 10 years.

The five-year alliance-style contract with Byrnecut is valued at circa-A$130 million/y ($101 million/y), OZ Minerals said. Byrnecut has already commenced a seven-week mobilisation to the Carrapateena site and will assume full responsibility for mining services delivery from March 4, 2021.

“OZ Minerals, Byrnecut and Downer will work together during the transition period to ensure continuity of operational performance and development, and employee support and opportunities, with the objective of providing roles for the majority of the incumbent underground workforce,” the company said. “This transition will include the transfer of equipment from Downer to Byrnecut.”

Byrnecut will now provide underground mining services to both the Carrapateena and Prominent Hill mines.

“Byrnecut is a proven top-tier underground mining contractor who has been providing underground mining services to Prominent Hill for the past 10 years, with their Prominent Hill contract having been renewed in 2020,” OZ Minerals said.

The scope of work comprises all underground mining activity for the duration of the contract including production and development mining and associated mining services; and bedding in steady-state operations at nameplate site capacity.