Tag Archives: Andrew Cole

OZ Minerals breaks through at Carrapateena sub-level cave

OZ Minerals has announced that the Carrapateena cave safely propagated to surface on December 29, 2022, marking the transition from development to production planning at the operation in South Australia.

OZ Minerals Managing Director and Chief Executive Officer, Andrew Cole, said: “The Carrapateena cave safely breaking through to surface marks a significant milestone for the mine and an important de-risking event for ongoing operations. With the cave now through to surface it enables mine planning to be optimised for production rather than prioritising the safe development of the cave, which has been the primary focus over the first two years of the mine’s life.

“I’d like to take this opportunity to congratulate the Carrapateena team for their dedication and focus to deliver a safe working environment and successfully managing the cave propagation to surface.”

Close to a year ago, the Crusher 2 level for the sub-level cave mine at Carrapateena was reached, enabling commencement of the Block Cave Expansion declines and an increase in sub-level cave production rates to from circa 4.7 to 5.0 Mt/y from 2023.

The expansion, which will involve converting the lower part of the current sub-level cave into a series of block caves, is expected to prolong operations at the copper-gold mine, while boosting production to 12 Mt/y. This will see average copper production come in at 110,000-120,000 t/y and gold output average 110,000-120,000 oz/y from 2026, compared with production of 55,262 t and 89,778 oz, respectively, in 2021.

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.”

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.”

OZ Minerals Board gives go ahead for shaft expansion at Prominent Hill

The OZ Minerals Board has approved construction of a hoisting shaft at the Prominent Hill copper-gold mine in South Australia, paving the way for a mine life extension and throughput expansion.

Prominent Hill mine began operation in 2009 as an open pit and is now an underground mine producing 4.5 Mt/y, moving to 4.5-5 Mt/y from 2022 via a trucking operation.

Coming with a pre-production capital expenditure of A$600 million ($436 million), the Wira Shaft expansion project will see the underground production rate increase to 6 Mt/y from 2025. At this point, the average annual copper and gold production is expected to be circa-54,000 t and circa-108,000 oz, respectively, some 23% more than expected in the current trucking operation.

The study leverages close to 100 Mt of mineral resources outside the previous Prominent Hill ore reserves of 38 Mt of underground material.

Sinking of the shaft is expected to commence in the March quarter of 2022. Mining and installation of underground and surface infrastructure is scheduled for completion along with commissioning of the Wira shaft at the end of 2024, with nameplate capacity expected in the first half of 2025.

The shaft design comprises a 1,329-m-deep, concrete-lined shaft with a diameter of 7.5 m. Construction of the shaft will be via conventional strip and line method, with the sinking period approximately two years.

The shaft mine expansion also enables generational province potential with further mine life extensions possible as 67 Mt of resource remains outside the shaft expansion mine plan, OZ Minerals says. Further, an exploration program has also identified that mineralisation remains open at depth beyond the current resource boundary, potentially accessible via the shaft.

Announcing the expansion today, OZ Minerals Chief Executive Officer, Andrew Cole, said: “We are thrilled to see a long and productive future for Prominent Hill with the Wira shaft mine expansion enabling access to areas previously thought uneconomic and opening up potential new prospects.

“Prominent Hill is a quality orebody and remains open at depth. The reliable performance of the operation and its consistent resource to reserve conversion rate were all influential in the decision.”

For the first time, the company has used a carbon price in determining the project valuation, a practice it plans to adopt in other OZ Minerals projects going forward, Cole said.

The company plans to reduce its underground loading fleet to eight vehicles, from nine after the shaft expansion, with its trucking fleet going from circa-14 to five, post-shaft.

Scope 1 emissions intensity per tonne of concentrate are also expected to drop from 0.47 t CO2-e/t to 0.28 t CO2-e/t after the shaft installation.

The pre-production capital of A$600 million, which was an increase on the A$450 million outlined in the November 2020 expansion study, enables transformation of the site in line with the strategic aspirations of OZ Minerals, it said.

Provisions have been included in site capital projections to support this transformation, including progressing underground fleet electrification, upgrading some of the existing infrastructure, remote operation capability and automation.

The company expanded on this: “A battery-powered mining fleet is part of the future vision as OZ Minerals moves towards its zero-carbon emission aspiration. For this study, diesel trucks were assumed. However, installation of enabling infrastructure is included in the Prominent Hill Expansion case to minimise future disruptions when the switch to an electric fleet occurs. This, implemented as part of the asset’s site-wide electrification aspiration, would contribute to a further reduction in Scope 1 emissions.”

A pilot study is also being undertaken to review a low-energy dry grinding option. The Prominent Hill Expansion Study is not directly connected to, nor dependent on this ongoing work, however, the work presents potential future cost reduction and other opportunities, OZ Minerals said.

OZ Minerals, Loesche team up following West Musgrave vertical roller mill test work

OZ Minerals, following a successful prefeasibility study of vertical roller mills (VRM) at the West Musgrave project in Western Australia, has signed a “Partnering Agreement” with Loesche.

The agreement with the leading original equipment manufacturer (OEM) of VRMs will help the company as it moves to the next phase of the project, OZ Minerals said.

“By working in a collaborative, innovative and transparent way, we believe we will deliver superior outcomes for the project when compared to more traditional ways of engaging with suppliers,” OZ Minerals said.

In November 2017, OZ Minerals and Cassini, which owns 30% of West Musgrave, announced that the West Musgrave project would progress to a prefeasibility study. This prefeasibility study timeline was extended in 2019 to complete a detailed evaluation of additional value-add opportunities, the most significant of which was the use of a dry VRM to reduce power consumption.

The study, released earlier this year, showed off plans for a 26-year open-pit mine with “bottom quartile cash costs” and average production of circa-28,000 t/y of copper and circa-22,000 t/y of nickel in concentrates, OZ Minerals said.

It also included details of an “innovative mineral processing plant” that would be built on site.

The grinding circuit for West Musgrave was expected to consist of two stages of crushing followed by two parallel VRMs treating nominally 5 Mt/y each. The second stage of crushing and VRMs replaced a traditional SAG mill, ball mill and pebble crushing circuit.

OZ Minerals explained in the study: “Vertical roller mills are widely used in the grinding of cement plant feeds and products, slag, coal and other industrial minerals, with thousands currently in operation worldwide. The mill has benefits in reducing power consumption by circa-15%, no ball charge grinding media, higher flotation recovery and can be ramped up and down in response to the availability of low-cost renewable energy.”

The VRM uses compression-style comminution principles taking 75 mm rock to flotation feed size in the one machine, according to OZ, adding that the application of the VRM had reduced processing costs and provided a circa-2% improvement in nickel recovery compared with a previous scoping study.

“The technology has been peer reviewed for West Musgrave by an independent expert and has been substantially de-risked through a series of pilot tests whereby 5 t of West Musgrave ore has been tested,” the company said.

Reviewing the prefeasibility study, OZ Minerals Chief Executive Officer, Andrew Cole, said: “We have been able to achieve a further significant reduction in carbon emissions and power demand through the adoption of vertical roller mills as the grinding mill solution and a flotation flowsheet which achieves metal recovery at a much coarser grind size than was previously considered in the design.

“This lower power usage has resulted in a reduction in operating costs, while the use of dry grinding from the vertical roller mills has also resulted in an improvement in nickel recovery.”

Another innovation the company plan to use at West Musgrave include the use of hybrid renewables that could include a combination of wind and solar energy, battery back-up, and diesel or gas.

Mining at West Musgrave is modelled to be conventional drill, blast, load and haul and is assumed to be contractor operated during the first five years of operation, transitioning to owner operate in year six.

The haulage fleet will comprise up to 25 220 t haul trucks and optionality is being maintained to allow for these trucks to be fully autonomous in the future, OZ Minerals said.

OZ Minerals eyes up block cave opportunities at Carrapateena underground mine

A prefeasibility study on an expansion of OZ Minerals’ Carrapateena copper-gold underground mine, in South Australia, has indicated a block cave conversion in the lower portion of the Carrapateena resource has the potential to almost double average production from 2026.

It is these results, plus the potential Block Cave 1 and Block Cave 2 expansion net present value of circa-A$770 million ($534 million) at final investment decision in 2023, that has seen the company confirm it will progress the plan to feasibility study stage, with the Carrapateena Block Cave Expansion Feasibility Study Stage 1 report expected before the end of 2021.

The PFS plan includes the potential to transition to dry-stacked tailings to reduce reliance on groundwater resources and a trial of electric light vehicles and establishment of a renewable energy hub – both of which are aligned with OZ Minerals’ strategy and aspirations, OZ Minerals Chief Executive Officer, Andrew Cole, said.

Carrapateena produced first concentrate in December 2019 following a three-year construction period and is targeting a 12-month ramp-up period to achieve a production rate of 4.25 Mt/y by the end of this year.

Currently an underground sub-level cave operation with an estimated mine life of 20 years, the latest study, which comes with a A$1.2-1.3 billion capital expenditure bill shows the potential for a future expansion of the bottom half of the operation into a series of block caves.

Cole said: “The prefeasibility study analysed the whole Carrapateena Province and determined that replacing the lower half of the current sub-level cave with a block cave and expanding the expected annual throughput rate from 4.7-5 Mt/y (currently planned from 2023) to 12 Mt/y, has the potential to create significantly more value than the sub-level cave alone.”

He said the block cave would leverage existing underground infrastructure, supported by expanded surface processing capability.

OZ Minerals added: “The proposed block cave is different from previous Carrapateena block cave studies as it targets a smaller, higher-grade footprint in BC1 (block cave one) with 600 m height of draw, followed by a lower-grade BC2 (block cave 2) with 400 m height of draw. The Carrapateena block cave builds on modern block caving experience, and aims to deliver an automated, electrified, data-driven mine with technology embedded in the design.”

The conversion to block cave operations enables a series of future add-on block caves, all of which were considered in the Life of Province scoping study, Cole added.

The plan could see annual production double to around 110,000–120,000 t of copper and 110,000–120,000 oz of gold from 2026, with life of mine all-in sustaining costs of some $0.75-0.85 c/lb ($1,654-1,874/t), he said.

Key upgrades to underground infrastructure include faster conveying systems with improved utilisation and a larger crusher station three for the block cave with increased capacity over that required for the sub-level cave.

An additional primary ventilation fan and circuit will be required for the transition period from sub-level cave to block cave before a reduction in the mine’s ventilation requirements for the life of mine, the company added.

The prefeasibility study currently recommends the process plant upgrade to 12 Mt/y via a parallel processing circuit to minimise brownfield interfaces and introduce energy load scheduling via the vertical roller mill as the primary surface crushing option, OZ Minerals said.

“The parallel process plant approach also allows both plants to be run independently, and for mine production to continue during plant shutdown periods,” the company said.

However, pivoting back to a traditional SAG/ball grinding circuit in the parallel process plant or tertiary crushing, to increase sub-level cave process plant throughput, will remain as options until final detailed design, OZ Minerals explained. This will not have a material impact on project value and allow time for optimisation of the current sub-level cave process plant before a final decision, it added.

OZ Minerals Carapateena copper-gold mine ramp up begins

OZ Minerals says it has now produced its first saleable copper-gold concentrate from the Carapateena underground mine, in South Australia, just over two years since the board approved the development.

The company said the first concentrate had been produced into the pre-filter press feed tank at the mine, with the achievement meeting the December quarter 2019 schedule mapped out when Board approval was given in August 2017.

Pre-production capital cost at first saleable concentrate is around A$970 million ($669 million) with 2019 growth capital spend on track for guidance of A$540-$570 million, the company said.

OZ Minerals commented: “Sufficient saleable concentrate is expected to be produced to the filter feed tank over the coming days to then complete our first concentrate press. Over 280,000 t of development ore is stockpiled on the surface as the mine now enters a faster circa 12-month ramp-up towards reaching a 4.25 Mt per annum throughput rate by the end of 2020, dependent upon the cave performing as expected.”

Chief Executive Officer, Andrew Cole, said: “This project began three years ago with initial decline works kicking off in Q3 (September quarter) 2016 followed by Mining Lease approval in April 2018 and first underground development ore in April this year.

“Today’s milestone represents the collaboration, support and hard work of a great many people including our operations and construction teams and the large number of contractors involved.”

He said the company’s key operational focus remains on underground development as the company ramps up the mine.

“The streamlined mine design with an expanded footprint will improve cave establishment, reduce risk during the ramp-up phase and may enable future annual throughput expansion opportunities as we continue to assess options to expand capacity above 4.25 Mt annually,” he said.

The company said this ramp-up period would allow it to test and optimise the plant throughout the first half of 2020 leading to gradual throughput and recovery increases to drive progressively higher output in the second half of the year. The now larger sub-level cave footprint along with an optimised mine design is expected to enable a faster cave ramp-up, provided the cave performs as modelled, the miner added, explaining that this would see the target 4.25 Mt/y run rate reached by end-2020 and the potential for a throughput boost.

Cole concluded: “Although we announce first saleable concentrate today, we have already commenced a block cave expansion scoping study looking at increasing both the life and production capacity of Carrapateena from 2025.”

Capital expenditure in 2020 will include permanent mine development, the circa-50 km Western Access Road construction and completion of conveyor installation and crusher, OZ said.

Production for 2020, as the ramp up progresses, is expected to be in the range of 20,000-25,000 t of copper and 35,000-40,000 oz of gold.

OZ Minerals Explorer Challenge winners crowned

OZ Minerals has awarded multiple prizes as part of the online crowdsourcing Explorer Challenge, organised in partnership with energy and resources open innovation platform Unearthed.

The submissions for the crowdsourcing competition to find new exploration targets at the Mount Woods tenements of the Prominent Hill copper-gold mine (pictured), in South Australia, ranged from cutting edge machine learning to advanced physical modelling, with OZ Minerals making more than six terabytes of public and private exploration data available to competitors.

The three month long competition concluded on May 31, 2019, having seen over 1,000 global participants from 62 countries register for the chance to not only win a A$1 million ($701,156) prize pool, but also have its concepts tested in real life, with the top targets scheduled to be drilled by the end of 2019.

First prize (A$500,000) went to Team Guru, a team made up of Michael Rodda (data scientist), Jesse Ober (environmental scientist) and Glen Willis (process engineering) for an approach that included interpretable machine learning models for mineral exploration using geochemistry, geophysics and surface geology.

Second prize (A$200,000) went to DeepSightX, a team made up of Dong Gong, Javen Qinfeng Shi, Zifeng Wu, Hao Zhang, Ehsan Abbasnejad, Lingqiao Liu, Anton van den Hengel, Karl Hornlund, and John Alexander Anderson. This team exploited multi-disciplinary skills at the intersection of artificial intelligence and geoscience, leveraging this to generate an artificial intelligence model to provide promising exploration targets in the Prominent Hill Region (PHR) supported by best practice geoscience.

Third prize (A$100,000) went to Hugh Sanderson, Derek Carter and Chris Green from team Cyency. Cyency has a strong data science and geoscience background, with Sanderson practising “deep learning” for several years, Carter being involved with the technical and software side of mining for over 10 years, and Green being an experienced geologist. The team said: “With so much data, it was difficult to know where to start, so we started with what we knew – the results from the Data Science Stream. We had a set of models that we knew were pretty good at predicting mineralisation across Australia, so we ran them over the tenement…we applied several data science techniques to estimate a set of candidate points, and then selected the 10 best of these.”

The Student Team prize of A$50,000 went to deCODES’ Christopher Leslie, Matthew Cracknell, Angela Escolme, Shawn Hood, and Ayesha Ahmed. A team of early career researchers from CODES, University of Tasmania, its approach was driven by considering an iron oxide copper gold (IOCG) metallogenic model, and then “striving to produce digital proxies for all aspects of that model. Our prospectivity layers were created using a mix of manual and traditional data handling methods as well as basic machine learning approaches”.

The Genius prize (A$25,000) went to Team OreFox’s Warwick Anderson, Sheree Burdinat, Kudzai Dube, Amy Leask, Alan Ryou Pearse, Ashleigh Smyth, and Nick Josephs. The brainchild of two exploration geologists, Anderson and Burdinat, OreFox has built up a team of experts with backgrounds in geophysics, data science, statistics, geology and prospecting to tackle the Explorer Challenge, using its proprietary artificial intelligence systems to analyse the data supplied by OZ Minerals as well as open source data obtained through Geoscience Australia and the SARIG database.

The Insights prize (A$25,000) was awarded to Avant Data Solutions, a multidisciplinary team consisting of data science and programming, and geological domain expertise. The team took a heavily data driven approach with verification and interpretation using geology, with the challenge tackled, first, by analysing and exploring the data in detail and finding what data might be overlooked.

The Data Hound and Fusion Prizes (both A$25,000) went to Team Phar Lap and SRK Consulting, respectively.
Team Phar Lap consists of a mathematician, a physicist, a German trained geologist and ecologist, a pilot, and a US trained geologist, offering a latticework of geosciences and data science. The consortium used a mixed approach between geological interpretation and data crunching with a strong focus on controlled learning.

SRK’s team was made up qualified structural geologists across offices in Perth, Melbourne, Toronto and Vancouver, with “the approach including the re-interpretation and/or value-add of the provided and available datasets followed by a multi-pronged and integrated targeting approach applying data-driven machine learning (based on a balanced random forest algorithm) and weights of evidence to guide a set of knowledge-driven mineral systems informed fuzzy inference solutions”, Unearthed said.

OZ Minerals Chief Executive Officer, Andrew Cole, said: “The innovators who participated in the Explorer Challenge have provided approaches to mineral exploration that we never would have imagined internally, including ways to fuse datasets together, combining multiple layers of information, and making predictions based on the extensive datasets.

“Reviewing the diverse range of solutions that have come back from this process has been truly remarkable.”
Unearthed Industry Lead – Crowdsourcing, Holly Bridgwater, previously worked for a decade as a geologist in resource exploration and definition. She believes that crowdsourcing will transform the lengthy and intensive exploration process.

“We are extremely excited by the incredible range of solutions submitted by these pioneers that can generate high quality exploration targets in an efficient way,” Bridgwater said.

“Many industry professionals and mining companies are beginning to realise that their true competitive advantage in exploration is speed, not necessarily data or technological intellectual property. I think that the ability that the crowd gives you to generate new ideas, develop solutions, and automate processes, is something that can make a big difference and provide that competitive advantage.”

CEEC’s latest workshop to examine new gen energy options for miners

With more and more mining sector interest in energy efficiency and uptake of renewables, the global not-for-profit communication hub for energy efficient mineral processing, CEEC, says it is running a series of workshops to share the latest developments in this field.

The next one-day Mineral Processing and Innovation Workshop on Energy Curves, Productivity and New Gen Energy, will be held at the National Wine Centre in Adelaide on June 19.

This event is due to kick off with a keynote address from OZ Minerals CEO and MD, Andrew Cole, who will share his vision for steering smart energy and productivity for sustainable mining, processing and communities.

Marc Allen, CEEC Director and Technical Director at engeco, said there was a worldwide trend towards new-generation energy options such as solar, battery-electric power and hydrogen – not only in the sector but for global power generation to combat climate change.

“The paradox is that these low carbon technologies are minerals intensive, and metals such as copper, nickel, lithium and cobalt will be required in greater volumes to make this transition possible,” Allen said.

“The shift towards a decarbonised energy future has significant ramifications for the global mining industry, particularly given the energy intensive nature of comminution and mining, coupled with the remoteness of most mineral deposits.”

Allen said renewable energy sources with low carbon energy backup options and/or energy storage were becoming more and more common in mines, with one leading example being the solar project at Degrussa Copper-Gold Mine in Western Australia.

Sandfire Resources’ Degrussa Solar project, commissioned in 2016, is reported to be the world’s largest integrated off-grid solar and battery storage facility. It supplies about 20% of the mine’s annual power requirements and has reduced emissions by close to 12,000 t/y of carbon dioxide, according to CEEC.

“South Australia is also leading the way with adopting new-gen energy. BHP is trialling zero-emission light electric vehicles at its Olympic Dam mine and has plans to progressively replace diesel fuel with lithium-ion batteries,” Allen said.

Canada’s first all-electric mine (Borden) is also on the cards, being constructed by CEEC sponsors Newmont-Goldcorp, Sandvik and MacLean Engineering.

Allen said: “Newmont-Goldcorp’s target is to increase energy efficiency by 15% over five years and source 5% of its energy from renewables. It’s pleasing to see that other major mining companies are fast following suit, introducing bold targets to shrink their carbon and energy footprint.”

Another standout country is Chile, with reports of nine companies, including copper miners Codelco and Antofagasta Minerals, introducing renewable energy such as wind and solar power.

In addition to transitioning to clean energy technologies, mining operations are striving to improve the energy efficiency of comminution. In Australia, alone, copper and gold mines’ comminution processes consume 1.3% of national electricity production, as well as being key constraints to site productivity, value and mining footprint.

Speakers and panellists at the CEEC Mineral Processing and Innovation Workshop in Adelaide on June 19 will share the latest technologies and methodologies being employed to boost energy efficiency, value and productivity in processing plants and mine sites, according to CEEC.

Keynote speaker Cole will be joined by leading mining, METS and research experts from across Australia, including Energy Curve researcher Dr Cathy Evans, Senior Research Fellow, University of Queensland Sustainable Minerals Institute; Professor Stephen Grano, Executive Director, Institute for Mineral and Energy Resources, University of Adelaide; and Professor Bill Skinner, Research Leader, Future Industries Institute, University of South Australia.

With data science and AI also being key drivers for improving operational efficiency and dispatch of electrical energy, workshop participants will hear from PETRA Data Science’s Managing Director, Dr Penny Stewart, and Technical Director, Dr Zeljka Pokrajcic.

Innovative METS leaders, including Greg Lane, Ausenco; Sandy Gray, Gekko Systems; and Bear Rock Solutions’ Dr Ted Bearman and Adjunct Professor Rob Dunne, will present practical advances in comminution technology.

Insights into South Australia mining and mineral processing innovations will be provided by Joe Seppelt, OZ Minerals Processing Manager at the Carrapateena copper-gold project, north of Port Augusta, and Enzo Artone, BHP Area Manager, Mill and Process Minerals, BFX Project, Olympic Dam.

To register or find out more about the workshop, which will be held at the National Wine Centre, click here.

OZ Minerals outlines block cave potential at Carapateena copper-gold project

OZ Minerals’ scoping study on an expansion at the Carrapateena copper-gold project, in South Australia, has shown that converting the lower portion of the sublevel cave to a block cave from 2026 could yield up to 60,000 t/y more copper output at the same time as reducing operating costs.

The Carrapateena sublevel cave is still in the development phase and is expected to hit first production in the December quarter of this year. This project is expected to produce an average of 65,000 t/y of copper and 67,000 oz/y of gold over a 20-year mine life.

The study outlined a more than doubling of mine throughput from 4.25 Mt/y to 10-12 Mt/y from 2026 through the development of the block cave and expanded surface infrastructure. This was expected to cost A$1-$1.3 billion ($704-$916 million) in upfront capital and lead to all-in sustaining costs going from $1.05/Ib ($2,315/t) in the sublevel cave operation to $0.90-$0.95/Ib during block cave operation.

The plan would see OZ Minerals access the higher-grade bornite mineralisation first, via the top-down sublevel cave, followed by a bottom-up block cave, OZ said.

Mine expansion and transition to a block cave would require adjustment to the location of future underground infrastructure below crusher station two, including a change in orientation of the decline, conveyor and ventilation, OZ said. In the current operation plan, this is not due for installation until after 2021.

The materials handling system and crushing infrastructure would require additional drive motors and a faster conveyor system to hit the new 10-12 Mt/y capacity, while there would need to be upgrades to the primary and secondary ventilation systems; electricity and communications infrastructure; and water supply, dewatering and underground facilities.

In terms of the process plant, there would need to be either a new parallel processing plant installed or an upgrade of the current sublevel cave processing plant.

OZ Minerals CEO, Andrew Cole, said: “The Carrapateena Block Cave Expansion work showed the conversion to a block cave to be the most value accretive next step for the Carrapateena resource and conceptually for the entire province, as it potentially enables a series of future add-on block caves, which themselves will now be the subject of a Carrapateena Life of Province Plan scoping study.”

He said the sublevel cave construction project remained on schedule for first production later this year, with ramp up to full production of 4.25 Mt/y taking place over the following 18 months.

The company will now move onto a prefeasibility study for the block cave expansion plan, which is expected to be completed by mid-2020.

Factoring in the scoping study results increases life of mine tonnes from 84 Mt at 1.8% Cu and 0.7 g/t Au, to around 145 Mt at 1.2% Cu and 0.5 g/t Au over a 20-year period.