Tag Archives: Olympic Dam

BHP to trial Epiroc Boomer M2 battery-electric jumbo at Olympic Dam mine

BHP has unveiled a battery-electric Epiroc Boomer M2 jumbo at its Olympic Dam mine in South Australia to help support the company’s target to reduce operational greenhouse gas (GHG) emissions, including by minimising reliance on diesel.

The 28.7-t, 14.5-m long battery-electric rig will be powered by a 150 kW traction motor and 150 kW battery system, eliminating greenhouse gas emissions from diesel-powered tramming. It will be tested for efficiency, productivity and comfort over the 12-month trial period, BHP said.

Jumbos are used in underground mining development to drill holes, which are then loaded with explosives and open up new areas. Post-blasting, jumbos install large bolts to stabilise mine walls. BHP currently operates 16 Epiroc jumbos at Olympic Dam.

The fully-electric machine will also break new ground in its user experience by reducing noise and vibration, and eliminating heat and the emissions of diesel particulate matter, the miner said.

Andrew Harris, General Manager Olympic Dam Mine, said: “The world is going to need a lot more of South Australia’s high-quality copper, and the team at Olympic Dam is behind our push to produce that copper more sustainably.

“Collaboration with supply partners like Epiroc will be critical to developing the technology required to reduce emissions, while ensuring we continue to improve the safety and productivity of our operations. I can’t wait to see what this new fully-electric jumbo can do.”

BHP’s Group Procurement Officer, James Agar, said: “The fully-electric jumbo is yet another innovation that will support our progress towards achieving our medium-term target of reducing operational greenhouse gas emissions by 30% by financial year 2030.”

Alisa Bennett, Underground Business Manager for Epiroc Australia and Mongolia, said: “Epiroc are excited to partner with BHP in a new era of electrification in Australia. Epiroc’s ambitious sustainability targets like halved carbon emissions by 2030 matches BHP’s sustainability agenda well. The Boomer M2 Battery rig will facilitate a healthier and safer underground working environment for our customers without compromising on productivity.”

BHP has a medium-term target to reduce operational GHG gas emissions by at least 30% by the 2030 fincial year, from a financial year 2020 baseline. Approximately 40% of BHP’s operational emissions in its baseline year came from diesel-powered vehicles.

The trial of the jumbo also supports BHP’s efforts to minimise the operational impact of diesel particulate matter in underground mining operations by 2025, as part of BHP’s participation in the International Council on Mining and Metals’ Innovation for Cleaner, Safer Vehicles initiative.

The fully-electric jumbo trial builds on electric vehicle initiatives at Nickel West in Western Australia, Olympic Dam in South Australia and BMA’s Broadmeadow mine in Queensland. BHP is also collaborating with Caterpillar Inc and Komatsu to develop zero-emissions electrified haul trucks, and battery-electric locomotives with Wabtec Corporation and Progress Rail.

BHP has also signed Power Purchase Agreements to source renewable power for a number of its operations in Chile, Queensland, South Australia (with Iberdrola and Neoen) and Western Australia. BHP also has customer decarbonisation partnerships with steelmakers in China, Japan, Korea, India and Europe, which collectively represent around 17% of reported global steel production capacity.

BHP eyes South Australian copper basin consolidation with latest OZ Minerals offer

BHP has submitted a revised non-binding indicative proposal to the Board of OZ Minerals Limited (OZL) that, subject to a successful four-week due dilligence period, could see the major miner acquire the mid-tier base metal-focused miner.

The offer to acquire 100% of OZ Minerals by way of a scheme of arrangement for a cash price of A$28.25/share ($18.9/share) is a 13% increase on the offer BHP previously put forwad and was rejected by the OZ Minerals Board. It, according to BHP, represents the best and final price the mining major is willing to offer under, in the absence of a competing proposal.

The OZ Minerals Board has confirmed to BHP that it intends to unanimously recommend the revised proposal to OZ Minerals shareholders as being in their best interests in the absence of a superior proposal, subject to the parties entering into a binding scheme implementation agreement (SIA) following completion of BHP’s confirmatory due diligence and an independent expert concluding that the revised proposal is in the best interests of OZ Minerals shareholders, it said.

The proposed transaction, valuing OZ Minerals at an enterprise value of A$9.6 billion, is expected to deliver significant value creation for both BHP and OZ Minerals shareholders, BHP says, explaining that OZ Minerals shareholders would receive an offer price significantly above trading levels and average broker price targets, prior to BHP’s initial proposal on August 5, 2022. At the same time, BHP shareholders would gain increased exposure to future-facing commodities, adding copper and nickel resources that are essential to support the global megatrends of decarbonisation and electrification.

The deal would also create a South Australian copper basin, which, according to BHP, could unlock potential operational synergies due to the proximity of OZ Minerals’ Carrapateena and Prominent Hill operations with BHP’s existing Olympic Dam asset (pictured) and Oak Dam development resource.

The West Musgrave project, meanwhile, will add a large greenfield nickel option to BHP’s Nickel West premier nickel sulphide resource position in Western Australia.

BHP has now entered into a Confidentiality and Exclusivity Deed with OZ Minerals in relation to the revised proposal. This has seen OZ Minerals grant BHP four weeks to undertake exclusive confirmatory due diligence and negotiate a binding SIA reflecting the key terms of the revised proposal. The four-week period is expected to commence on or around November 21, 2022.

BHP CEO, Mike Henry, said: “BHP’s proposal represents a highly compelling offer for OZ Minerals shareholders, providing certainty at a time of macroeconomic uncertainty and market volatility, and increasing risks for the industry.

“The combination of BHP and OZ Minerals’ assets, skills and technical expertise provides a unique opportunity not available under separate ownership, with complementary resources including the Oak Dam exploration prospect and existing facilities within close proximity, backed by BHP’s strong balance sheet, capital discipline and commitment to sustainable development.”

OZ Minerals Managing Director and Chief Executive Officer, Andrew Cole, said: “BHP’s revised proposal is a clear reflection of OZ Minerals’ unique set of highly strategic, quality assets in quality jurisdictions and an enviable multi-generational growth pipeline of copper and nickel
assets in strong demand due to global electrification. We look forward to working with BHP in a collaborative way to progress the revised proposal in the best interests of OZ Minerals’ and its stakeholders.”

Monadelphous banks work with Fortescue Metals and BHP

Monadelphous has secured new contracts and contract extensions in the resources and energy sectors totalling approximately A$150 million ($96 million), including work with Fortescue Metals Group and BHP.

The company has been engaged to provide construction services at the Iron Bridge Magnetite Project, an unincorporated joint venture between Fortescue subsidiary FMG Iron Bridge and Formosa Steel IB, in the Pilbara of Western Australia. The work, which includes the provision of structural, mechanical and electrical and instrumentation services at the wet process plant, is expected to be completed by the end of 2022.

Monadelphous has also secured the following work with BHP:

  • A contract for the remediation of balance machines at the Finucane Island and Nelson Point ports in Port Hedland in Western Australia, with work expected to be completed by mid-2024;
  • A 12-month extension to its existing contract to provide general maintenance and shutdown services at BHP’s Western Australian iron ore operations;
  • A 12-month extension to its existing maintenance, shutdown and project services contract across BHP’s Nickel West operations in Western Australia; and
  • A two-year contract to provide construction services under the Olympic Dam Construction Panel Framework Agreement at Olympic Dam in South Australia.

BHP partners with Neoen on Olympic Dam renewable power pact

BHP says it has signed a renewable Power Purchase Agreement (PPA) with Neoen, which is expected to meet half of Olympic Dam’s electricity needs from its 2026 financial year.

The agreement, which is based on current forecast demand, will allow Olympic Dam to record a net zero emission position for the contracted volume of supply, according to BHP.

The PPA is expected to supply 70 MW of electricity to Olympic Dam and will support Neoen to construct the 203 MW Goyder South Stage 1b Wind Farm, assuming all relevant consents are obtained, BHP said. This wind farm is to form part of the larger Goyder Renewables Zone in South Australia, and will introduce new renewable generation into the South Australian electricity grid.

In addition, Neoen will construct a large-scale battery energy storage system in Blyth, South Australia, to support the PPA, which will also assist in improving the stability of the South Australian electricity grid.

Goyder South Stage 1, consisting of Goyder South 1a and 1b, is the first stage of Neoen’s flagship project known as Goyder Renewables Zone – a hybrid wind, solar and storage project located in mid-north South Australia. Goyder South has development approval for a total of 1,200 MW of wind generation, 600 MW of solar generation and 900 MW of battery storage capacity – making it South Australia’s largest renewable project.

BHP Olympic Dam Asset President, Jennifer Purdie, said: “The world needs South Australia’s high-quality copper to build renewable technologies and infrastructure, and BHP is focused on producing that copper more sustainably.”

“This agreement will support BHP on its decarbonisation journey, and provide new firmed renewable energy and increased stability to the South Australian grid.”

This latest agreement follows commitments BHP has made in recent years, which have seen renewable electricity contribute to powering BHP facilities in Western Australia, South Australia, Queensland and Chile.

This PPA continues the actions BHP is taking to contribute to its medium-term target to reduce operational greenhouse gas emissions (Scopes 1 and 2 from its operated assets) by at least 30% from adjusted 2020 financial year levels by its 2030 financial year.

BHP’s Chief Commercial Officer, Vandita Pant, said: “BHP is consciously working towards our target of at least a 30% reduction in our operational emissions by FY2030. Renewable energy partnerships, such as this agreement with Neoen, are important steps towards that outcome, and our longer-term 2050 net zero goal.”

Louis de Sambucy, Neoen Australia’s Managing Director, said: “We are delighted to provide BHP with this highly innovative solution. We are convinced that our ability to combine our assets and our energy management capabilities to create bespoke commercial offers will be a key element of success for our future developments.”

Xavier Barbaro, Neoen’s Chairman and Chief Executive Officer, added: “We thank BHP for their vote of confidence. Thanks to its storage assets and deep expertise, Neoen is now able to offer 24/7 energy to its customers. This first baseload PPA is a significant step forward for Neoen and will serve as a template for future contracts, opening up new market opportunities in Australia and in the rest of the world.”

Neoen, BHP says, is one of the world’s leading independent producers of exclusively renewable energy, having close to 5.6 GW of solar, wind and storage capacity in operation or under construction across numerous countries.

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.”

Escondida, Spence and Olympic Dam production practices recognised with Copper Mark

BHP’s Chilean operations Escondida and Spence, and Olympic Dam in Australia, have been awarded the Copper Mark, recognising responsible production practices after an independent assurance process, the miner says.

The Copper Mark is an assurance framework specific to the copper industry, developed to ensure value chain participants demonstrate best practice in responsible production and contribute to the United Nations Sustainable Development Goals. Copper Mark is a voluntary program that independently assesses participants in 32 critical areas including environment, community, human rights and governance issues for mining, smelting and refining operations.

The Copper Mark uses the Risk Readiness Assessment (RRA) of the Responsible Minerals Initiative (RMI) and the Joint Due Diligence Standard for Copper, Lead, Nickel and Zinc, as the basis for evaluating participants’ performance.

BHP submitted Letters of Commitment for Escondida (pictured), Spence and Olympic Dam to the Copper Mark Responsible Production Framework on October 31, 2020. The Copper Mark was awarded to Olympic Dam on September 21, 2021, while Spence and Escondida were each awarded theirs on November 2, 2021.

BHP’s Group Sales and Marketing Officer, Michiel Hovers, said: “Long-term sustainability credentials are important to our customers and increasingly important to end consumers of copper products, such as buyers of electric vehicles and copper intensive consumer durables.”

BHP’s Mineral Americas President, Rag Udd, added: “Copper Mark is a step forward in developing an industry-wide approach to transparency and standards for the copper value chain and reinforces the value BHP places on responsible, sustainable production.

“Copper is a future-facing commodity and our operations have an important role to play in providing high quality and sustainable copper that is essential to the energy transition. Escondida, the largest copper producer in the world, operates 100% with desalinated water and, along with Spence, is aiming to achieve 100% renewable power by the mid-2020s.

“It is important to our customers, investors, employees, communities and governments to ascertain the ethical and sustainable production of copper along the value chain.”

BHP Olympic Dam Asset President, Jennifer Purdie, said the team was thrilled that Olympic Dam has become the first site in Australia to be awarded the Copper Mark.

“Olympic Dam is a multi-generational orebody and one of the world’s most significant deposits of copper, gold, silver and uranium,” she said. “The Copper Mark accreditation provides an industry-wide approach to transparency and sustainability in the copper value chain and provides our customers with confidence in the copper they purchase. Award of the Copper Mark will help us to keep sustainably delivering jobs, investment and economic and social value.”.

The Copper Mark’s Executive Director, Michèle Brülhart, said: “We are delighted to welcome Escondida, Spence and Olympic Dam among the recipients of the Copper Mark. We are particularly pleased to see the first Australian site to receive the Copper Mark with Olympic Dam while we continue to grow our footprint in the world’s main copper producing country, Chile. We congratulate the three sites for their achievement and their commitment to responsible production practices.”

BHP closes in on renewable energy supply for Olympic Dam mine

BHP says it expects to shortly enter into renewable energy supply arrangements to enable the Olympic Dam mine in South Australia to reduce its emission position to zero for 50% of its electricity consumption by 2025, based on current forecast demand.

The arrangements will be supplied by Iberdrola, including from the Port Augusta Renewable Energy Park in South Australia, which is expected to be Australia’s largest solar-wind hybrid plant once in operation in July 2022.

BHP is to become the primary customer of this new renewable facility, with the renewable energy supply arrangements referred to including a retail agreement with Origin Energy, who will facilitate the arrangements.

This announcement follows BHP’s entry into renewable energy agreements for BHP’s operations in Western Australia in 2021, Queensland in 2020 and in Chile in 2019.

BHP Olympic Dam Asset President, Jennifer Purdie, said: “These arrangements will support an exciting new renewable energy project which will contribute to South Australia’s renewable energy ambitions.

“Olympic Dam’s copper has an important role to play to support global decarbonisation and the energy transition as an essential product in electric vehicles and renewable infrastructure. Reducing emissions from our operations will further enhance our position as a sustainable copper producer.”

Iberdrola Australia Chief Executive Officer and Managing Director, Ross Rolfe, said: “We are delighted to be partnering with BHP, helping them meet their decarbonisation and sustainability objectives. We worked very closely with BHP to design these bespoke renewable energy supply arrangements. Olympic Dam is to be the primary customer for the Port Augusta Renewable Energy Park, a demonstration of their commitment to local procurement and sustainable economic development.”

The arrangements, intended to commence on July 1, 2022, are one of the actions BHP is taking to contribute to its medium-term target to reduce operational greenhouse gas emissions (Scope 1 and 2) from its operated assets by at least 30% from financial year 2020 levels by financial year 2030.

BHP contracts indigenous-owned Zancott Knight for Olympic Dam refuelling services

In the lead-up to the 20-year rebuild of the flash furnace at BHP’s Olympic Dam mine in South Australia, the miner has awarded a A$1.8 million ($1.3 million) contract for refuelling services to local, indigenous-owned company Zancott Knight.

The flash furnace rebuild is part of the current smelter maintenance campaign, SCM21, at Olympic Dam, with BHP actively seeking out opportunities for local, small and indigenous businesses to be part of the action, Jenny Purdie, Asset President Olympic Dam, told attendees at the Copper to the World Conference in Adelaide, yesterday.

Purdie said Zancott Knight is a local, indigenous-owned company closely connected to the Arabana community. She added that Zancott Knight has brought in a sub-contracting partner, WB Enterprises, who are closely connected to the Kokatha community, to carry out the refuelling services contract.

Both these groups make up two of the Traditional Owner partners Olympic Dam engages with, she said.

BHP’s global operations spend approximately $2 billion with small, local and indigenous businesses each and every year, Purdie added.

Monadelphous Group banks engineering work with BHP, Rio and Codelco

Monadelphous Group Ltd has secured several new construction and maintenance contracts in the resources sector totalling around A$215 million ($163 million).

Included within this slate of new work is a contract for smelter campaign maintenance works at the BHP owned Olympic Dam copper mine in South Australia. Monadelphous said work will commence immediately and is expected to be completed in December 2021.

Monadelphous has also been awarded a two-year extension to its existing maintenance services contract at Olympic Dam. The contract scope includes civil, structural, mechanical, building maintenance and electrical services, as well as the addition of underground rail maintenance services.

In the iron ore sector in the Pilbara region of Western Australia, Monadelphous has been awarded several contracts, including several sustaining capital contracts under its panel agreements with BHP and Rio Tinto; and a contract with Rio for the provision of construction and support services associated with the Gudai-Darri iron ore project, with work expected to be completed by the end of 2021.

In Chile, the company’s maintenance and construction services business, Buildtek, has secured a number of new contracts, including a three-year contract with Codelco for the operations and maintenance of water infrastructure at the Chuquicamata underground mine in Calama. Buildtek has been providing these services on this site since 2018.

In addition, the engineering company has secured two new contracts with Codelco for maintenance activities associated with the concentrator plant at El Teniente mine in Rancagua; and a contract with BHP Minera Escondida for the construction of modularised pump stations and associated infrastructure of the Escondida copper mine in Coloso.

Finally, Monadelphous, in collaboration with global heavy lifting services company Fagioli, has secured a contract with NMT International (Australia) to deliver specialist heavy lifting and haulage services at the Iron Bridge magnetite project, a joint venture between Fortescue Metals Group subsidiary FMG Magnetite Pty Ltd and Formosa Steel IB. The strategic collaboration with Fagioli enables Monadelphous’ specialist Heavy Lift business to increase capacity and broaden capability for the Australian resources and energy markets, it said.

CRC ORE simplifies complexity for value

“There are a lot more variables to bulk ore sorting than just the technology,” Jon Rutter says.

The Principal Geologist of the Cooperative Research Centre for Optimising Resource Extraction (CRC ORE), Rutter knows his stuff. He has worked underground in both narrow-vein and mass-mining operations, as well as at large scale open-pit mines; in the base and precious metal arena.

During a presentation at International Mining Events’ IPCC Virtual event in early-February, he shared a slice of this knowledge while reviewing a recent installation project CRC ORE had been involved in at a platinum group element (PGE) operation.

“The intrinsic value of bulk ore sorting comes from the delivered heterogeneity,” Rutter said. “We have got to be able to sense and divert a higher-value pod of material versus an adjacent pod of lower-grade material on a conveyor.

“You essentially want to put more material into the mill that adds value – and not what destroys value.”

Looking at the wider bulk sorting opportunity in mining, Rutter explained the sensor diversion units (SDU) in bulk ore sorting were smaller than what the mine itself can typically offer in the form of a selective mining unit (SMU), which may be comprised of a dig block totalling around 15,000 t.

A truck offers a 100-300 t opportunity, while a shovel typically comes with a 50-100 t opportunity.

Even with a modest conveyor running at a 2,000 t/h rate, an on-board sensor (eg PGNAA or PFTNA) running at a 30 second integration time (the time to analyse one grade) would provide an SDU of 16.7 t. A sensor with lower integration time (eg XRF at 10 seconds) comes in at 5.6 t.

The ability to provide analysis down to this level has enticed several major companies into testing bulk ore sorting solutions.

Anglo American has trialled bulk ore sorting solutions at copper and platinum group metal mines, while BHP recently engaged CRC ORE to examine deployment of cutting-edge preconcentration techniques under its Grade Engineering® platform at the Olympic Dam mine, in South Australia.

The SDU with bulk sorting may be that much smaller than the SMU of a typical mine plan, but lab-level precision is not required for these solutions to work, according to Rutter.

“What I need is the ability to measure the metal content adequately,” he said. “When I say adequate, this incorporates the entire error bar of the system. That system includes the inherent geology, the mineralisation style and heterogeneity. We also need to consider the precision, accuracy and integration time – which is the technology constraint; but we also need to include the weightometers, the flop gates, the diversion gates, as well as that entire mining and materials handling process right from the start – from blasting, loading, hauling and dumping to the plant.

“But for bulk ore sorting what I end up requiring from this combined data is usually a binary decision: am I above or below a certain threshold?”

He expands on the bulk ore sorting (BOS) assessment process: “The other way of looking at this is simply considering it as planned ore loss and dilution. If we go back into that dig block, in that 15,000 t of material, I’ve already incorporated planned ore loss and dilution decisions or parameters into that SMU decision. So, if we look at bulk ore sorting, I am just talking about those different attributes – the error bars of a BOS system – as the inputs or parameters for BOS planned ore loss and dilution – it’s now just at a smaller and more precise opportunity.”

The company took a two-phase approach to the BOS opportunity at the PGE operation in question.

The first phase involved carrying out heterogeneity analysis of the orebody; correlation analysis of PGEs to base metals; selection of sensor technologies (XRF and PGNAA were selected in this case), design, layout and equipment selection for the bulk ore sorting plant; natural deportment analysis of the orebody; development of a preliminary business case; the ore type selection and sampling strategy; and project planning and management.

CRC ORE and the company in question settled on a solution where a Caterpillar 992 wheel loader dropped material off to a system using a combination of grizzly, feeder, sizer, conveyors, diverter, stackers and associated equipment from MMD, used in conjunction with an ore sensing system equipped with both PGNAA and XRF sensors to continuously measure the elemental composition. The PGNAA sensor provided a “penetrative” analysis calculation whereas XRF provided a “surface” sensing calculation, Rutter explained.

An incline conveyor ahead of the diverter gate and the accept/reject stream provided the 30 second integration time the PGNAA analyser required.

Phase two of the project involved online and offline (pre-install) work; sensor calibration; proving the technology; and proving the technology can drive physical separation.

Rutter said the completion of static calibration of the sensors saw the PGNAA sensor 20-30% calibrated, and the XRF sensor 70-80% calibrated.

This outcome harked back to Rutter’s assertion that “bulk ore sorting implementation is not a plug and play opportunity”.

A dynamic calibration in online mode completed under normal conditions was required to get the PGNAA sensor up to speed. This process, meanwhile, solidified the operation of the XRF sensor.

While the two sensors were calibrated in different ways, Rutter showed data that confirmed both were in unison when it came to reading the ore/waste that came through the conveyor (see right-hand graph below).

“The two sensors are independent of each other and fundamentally very different, but they can work well together, or separately,” he said.

CRC ORE was able to prove the technology by running the same sample through the circuit a number of times, as Rutter explained: “We fed 15-20 t of run of mine material into the hopper and repeated the process 15 times, putting the same 15-20 t sample through the system. We could then start to determine the precision and accuracy of the sensors and the system.”

For further verification, the sample was crushed, sub sampled and assayed.

“We wanted a binary response to ore and waste to build confidence,” Rutter added.

Phase three involved the ramp up to production scale, going from, say, 500 t/h to 1,000 t/h; carrying out validation by campaign; and finally integrating with the operation.

There were several lessons all mining companies – and bulk sorting vendors – should keep in mind from such a project, Rutter said.

Operations need to assess the impact of mixing across the entire materials and mining handling process as soon as possible, for one.

“The earlier we can put this data into the system, the better,” Rutter said. “Without a heterogeneity signature, we cannot implement bulk ore sorting.”

He also stressed the importance of timely feedback. Sensor calibration, a secondary crushing/sampling plant and assaying were all required to build confidence in the solution.

Rutter added: “The proper calibration of sensors does require a considerable and ongoing effort…but that is no different from any other process plant or equipment.”

Operators also need to be wary of where they set these solutions up in mines, recognising this heterogeneity dynamic.

“Bulk ore sorting is quite unlikely to be universally suited to the entire deposit,” Rutter said. “The analogue for this is a flotation plant; there are ore types in the mine where you achieve better performance in the flotation plant and others where you get worse performance.”