Tag Archives: Arizona

Metso-Arizona

Metso expands Arizona service centre on copper mining demand

Metso is expanding its service centre in Mesa, Arizona, to, it says, support the growing needs of mining customers, primarily in the copper segment, which plays a crucial role in supporting a responsible energy transition.

In addition to expanding its service and repair capabilities, a cutting-edge training centre will be built to continue to improve competence development in the region, it says.

Giuseppe Campanelli, President, North and Central America, Metso, said: “We are proud to be able to further demonstrate our dedication to customer success, supporting the production of critical minerals. This investment will provide great benefit to the southwest USA and beyond, with comprehensive and reliable services. Our expanded facilities in Mesa will allow access to unmatched OEM-quality repairs and refurbishments, and the new advanced Metso Training Center will help ensure that the next generation of miners are well-equipped.”

The total investment value is approximately €14 million ($15 million), with expansions expected to be ready during the first half of 2025.

With further investments in the Mesa Service Center, Metso will optimise safety, sustainability and broaden its service capabilities. The expansion will increase the repair shop area by nearly 60% and add new high-capacity cranes, CNC machines, welding and assembly stations. This will increase the capacity and capability to perform heavy equipment repairs and service a wider range of equipment, spanning process steps such as crushing, screening, grinding, HPGRs, filtration, flotation and pumps, among others.

Annami Toukoniitty, Senior Vice President, Professional Services, Metso, said: “Metso is proud to invest and support this sustainable journey as increased repair capabilities have a direct positive impact on the circular economy. Skilled people are a core asset as well, and the new Metso Training Center at Mesa will add value to the industry.”

Aligned with customer demand, this is the second expansion of the Mesa Service Center since its opening in 2015. Numerous upgrades to the facility to improve energy efficiency are also being implemented. In addition to the service centre, since 2021, the Phoenix region is also home to one of Metso’s largest warehouse operations globally.

Within the same property, an advanced and fully-equipped training centre will also be built, to bridge the knowledge gap between people, equipment and operational goals, Metso says. The centre will support multiple ways of learning, outfitted with state-of-the-art simulators and digital training assets, in addition to classroom and hands-on learning areas. Comprehensive and tailored training programs will be designed and offered to support mining professionals’ technical knowledge, at the part, equipment and plant level.

Metso says it has an extensive service centre network with over 3,000 field services professionals, technical support and more than 40 service centres on six continents.

Intramotev to put rail back in mining material movement competition

St Louis-based Intramotev is looking to rekindle the mining and rail relationship that made US operations viable in some of the country’s most remote places by using a modular battery-electric propulsion system and an autonomous-ready operating platform that can provide shipment certainty, safety and sustainability.

Founded by Tim Luchini, Alex Peiffer and Corey Vasel, Intramotev has come to the table in the last four years with a portfolio focused on autonomous, zero-emission rail solutions.

The company has brought together a team from the rail, aerospace and automotive sectors to revolutionise and revamp the rail sector, looking to provide the “speed and flexibility of trucks with all the advantages of rail”, Luchini, also CEO, told IM.

“Through our solutions, we can offer the rail industry 20% to 100% reductions in their emissions footprint, while lowering their all-in costs by 30-80%,” he says.

Such metrics, which could encourage mine site expansions as well as new greenfield operations to start up, will be achieved by deploying one of the two solutions Intramotev has in its portfolio:

  • TugVolt, a proprietary kit that can retrofit/upfit existing rail cars to become battery-electric; and
  • ReVolt, capturing waste energy in traditional trains via regenerative braking, and automated safety systems including gates and hatches.

TugVolt can decouple to independently service first- and last-mile legs, providing the type of flexibility that, Luchini says, will allow the system to more readily compete with trucking. ReVolt, meanwhile, stays in the consist to capture energy via regenerative braking and reduce the overall diesel consumption of locomotives.

Both solutions leverage battery-electric technology – with Luchini saying the rule of thumb would see a 100 kW battery on board a rail car able to transport a 100 t payload for 100 miles (160 km).

“This compares very favourably with the massive batteries companies are having to put into rail locomotives to provide hybrid consists,” he said. “We’re offering something much more scalable to allow operators transporting large volumes of materials via rail an opportunity to electrify their fleet and reduce their costs.”

The first mining company to publicly commit to such a solution is Iron Senergy, which is set to receive three ReVolt rail cars for its 17 mile private rail line that transports coal produced by its Cumberland longwall coal mine, in Waynesburg, Pennsylvania, to its Alicia Harbor Facility on the Monongahela River, in western Pennsylvania.

This will be the world’s first deployment of self-propelled battery-electric rail cars in a traditional freight train when it starts up by the end of the year, according to Intramotev, using regenerative braking and battery technology to reduce diesel consumption from locomotives, resulting in lower costs for rail operators and reducing emissions impact from rail operations.

Tim Luchini, co-Founder and CEO of Intramotev

This might be the first, but there are plenty more in the works, according to Luchini.

“We have a pipeline of 168 rail cars today which are at different levels of commitment,” he said, adding that, of this total, there was a roughly even split between enquiries for TugVolt and ReVolt.

“We’re expecting payback periods on projects to be as little as six months, so there is a real economic case to employ these solutions, as well as the ability to reduce your emissions,” he said.

The US represents a massive market for the company to aim for – close to a million freight rail cars sit idle in switching yards, awaiting locomotives to bring them to their destination, according to the company – but Luchini also sees opportunities in Canada and South America where North American rail standards are already present.

“Then there is a region like Australia to consider, which obviously has a rich history of mining with remote operations in need of affordable and low-emission transport infrastructure,” he added.

The ability to add spur and extensions onto existing lines and run smaller units of battery-electric rail cars – like the company thinks can be achieved in the likes of Arizona, Nevada and Minnesota – could provide serious competition to the trucking sector there.

Luchini concluded: “If you are a mine site today, you have an obvious tension when it comes to material movement.

“Conveyors are great material movers but can cause huge issues when they fail; trucks are fast and flexible but come with excess emissions by today’s standards; rail is low cost, fast and environmentally responsible but in its current form is not very flexible.

“We’re looking to change this dynamic, going back to the rail sector’s heritage as a mine operation facilitator.”

Ivanhoe Electric planning for all-electric underground fleet and Railveyor tech at Santa Cruz copper project

Ivanhoe Electric has published the results of an Initial Assessment (IA) carried out on its Santa Cruz copper project, in Arizona, USA, highlighting the potential to build a 5.9 Mt/y underground mining operation that uses an all-electric underground heavy mining fleet, in combination with Railveyor technology for material movement.

The use of an all-electric underground heavy equipment fleet alone represents an estimated 70-80% reduction in Scope 1 emissions when compared to a traditional high-efficiency diesel-powered heavy equipment fleet, Ivanhoe says, adding thatthe use of Railveyor technology would further the efficiencies associated with moving mined mineralisation from underground to surface.

The IA base case assumes 70% of the total electric power requirements for the project will be generated by on-site renewable infrastructure, enabling copper production with very low carbon dioxide equivalent (CO2e) emissions of 0.49 t of CO2e per tonne of copper for Scope 1 and 2 emissions. This compares favourably with a global mining industry average of approximately 3.9 t of CO2e per tonne of copper equivalent, Ivanhoe says. The subsequent prefeasibility study for the project will evaluate the potential use of combined solar power, battery storage and a geothermal-driven microgrid as renewable power sources to provide up to 100% of the electricity requirements for the project.

The Santa Cruz IA outlines a potential 5.9 Mt/y underground mining operation, supported by 105.2 Mt of modelled mill feed with an average grade of 1.58% Cu from the Santa Cruz and East Ridge Deposits, resulting in an estimated 20-year mine life.

The IA focuses exclusively on the high-grade exotic, oxide and enriched domains of the Santa Cruz and East Ridge Deposits, with the oxide and enriched domains of the Texaco deposit not included in the current study (2.7 Mt indicated grading 1.42% total copper and 27.3 Mt inferred grading 1.39% total copper, using a 0.80% cut-off grade).

Future studies could evaluate the potential addition of the large primary sulphide domains at Santa Cruz (76.2 Mt indicated grading 0.88% total copper and 8 Mt inferred grading 0.92% total copper, using a 0.70% cut-off grade) and at the Texaco Deposit (900,000 t indicated grading 1.05% total copper and 35 Mt inferred grading 1.06% total copper, using a 0.80% cut-off grade), subject to market conditions.

Copper recoveries of 95.4% are expected to be achieved through a combination of solvent extraction and electrowinning and conventional froth flotation. The IA includes life of mine production for the project of 1 Mt of copper in the form of 99.99% pure copper cathode and 600,000 t of copper contained in a 48% copper concentrate with very low deleterious elements, such as arsenic or lead.

The IA contemplates initial project capital expenditures of $1.15 billion, and life of mine sustaining capital expenditures totaling $0.98 billion. A three-year construction period is envisioned to develop the underground workings and build the surface processing facilities.

As a result of the small surface footprint required for underground copper mining activities included in the IA, the total land area expected to be required for the mine, plant, tailings storage facilities and potential on-site generation of renewable solar power covers approximately one-third of the total land package.

The IA also contemplates placing 50% of the mine tailings back underground as cemented paste fill. The remaining 50% will be stored on the surface as thickened tailings at 65% solid content. Surface tailings will be contained within a ring dyke dam with a capacity to store 56.7 Mt. Water management associated with tailings storage is minimised as a result of thickened tailings and high evaporation rates in the Sonoran Desert, the company says.

Executive Chairman, Robert Friedland, said: “Completing the Initial Assessment for our Santa Cruz copper project is an important achievement for Ivanhoe Electric as we work to advance a new source of responsibly produced ‘green’ copper in the United States. Our goal is to develop a modern copper mine that produces copper with among the lowest levels of carbon dioxide output in the industry; a product we think has the potential to attract a premium price in the future.

“Using primarily on-site renewable electricity generation, and with the potential to increase that to meet the project’s entire future needs, the IA shows us that we are on the right track to achieving our goal at Santa Cruz and our larger goal of enhancing US supply chain independence for critical metals. We are excited about the future for our Santa Cruz project in Arizona.”

In the IA, twin declines, each measuring 4.3 km, would be developed to access the upper parts of the Santa Cruz and East Ridge deposits. One decline is required for air intake and access, while the other will be required for air exhaust and material movement. To develop the declines, the IA assumes that construction of the portal box cut would begin in 2026, decline development in 2027 and continues through 2028 to access the top portion of the mine. Under these assumptions, stoping activities would begin in 2029 with a one-year ramp up to the full 15,000 t/d capacity.

Mining of the upper portion would proceed for the first eight years before additional capital expenditures are required to extend the declines by 1.9 km. Additional surface infrastructure would be required once mining of the lower portion commences. This would include the second phase construction of a refrigeration plant, ventilation, water handling and material handling.

Mine sequencing would employ typical transverse longhole stopes for the Santa Cruz deposit on a primary-secondary sequence with paste backfill for support. Mining of the Santa Cruz exotic mineralisation has been evaluated using a drift and fill technique with access from the Santa Cruz longhole stoping levels. The East Ridge deposit will apply a drift and fill mining technique with access directly from the twin declines.

Over the total life of mine, 105.2 Mt of mineralised material is expected to be mined. This includes 88.6 Mt from the Santa Cruz deposit, 1.9 Mt from the Santa Cruz exotic mineralisation, 9.8 Mt from the East Ridge deposit and 4.9 Mt of low-grade material required to access the deposits.

Metso to supply SAG mills and mill liners to Origin Mining’s Mineral Park project

Metso says it has been awarded orders for the delivery of grinding plant equipment to Origin Mining Company’s brownfield Mineral Park Mill Restart project in the US.

Origin Mining is managed under the Waterton Global Resource Management umbrella of investments, with Mineral Park in a historic, copper-rich mining district next to Kingman, Arizona. The total value of the order is €16 million ($17.4 million).

Metso’s scope of delivery includes two Planet Positive Premier® SAG mills and Skega Poly-Met™ mill liners, and the possibility to supply other comminution and beneficiation process equipment technologies later.

Jack McMahon, President of Origin Mining, said: “We have been impressed with Metso’s commitment to support our vision to grow the USA copper supply. Metso’s leading comminution and beneficiation process equipment technologies will help us do our part to contribute to the transition to an electrified future.

“Metso has actively supported the project in a time responsive, technical and open manner, allowing for ’fit for purpose’ process solutions. We also value Metso’s ability to provide the necessary value added after-sales services in Arizona to support our operation.”

Tim Robinson, Vice President, Minerals Sales in North and Central America at Metso, said: “We are very excited to support Origin Mining in their drive to develop and supply locally key battery minerals, like copper, in the USA. Our industry-leading products and large service team in Arizona is committed to supporting them in this quest.”

South32 and Redpath kick off shaft sinking works at Hermosa

South32 has now broken ground on one of two exploration shafts at the Hermosa project in southern Arizona, USA, in a sign of major progress at the base and battery metal project.

This milestone achievement commemorates the initial surface excavation that will be continued by Redpath USA to a planned depth of 900 m, the contractor stated in a LinkedIn post. Redpath and South32 signed a “limited notice to proceed” for shaft engineering and design at Hermosa last year.

Redpath said in this latest post: “The shafts will enable underground access for continued exploration of a world-class deposit containing the US critical mineral zinc as well as lead and silver – minerals needed for supporting electrification and renewable energy.”

In South32’s March quarter results, the company said it invested $176 million over the last nine months as it continued critical path activity and study work for the Taylor zinc-lead-silver deposit and the Clark battery-grade manganese-zinc-silver deposit. It also directed $12 million to capitalised exploration in the nine months ended March 2023 as it continued exploration programs at Taylor and Clark and the copper-lead-zinc-silver Peake prospect 8.

Just last month, the Hermosa project was confirmed by the United States Federal Permitting Improvement Steering Council, an independent federal agency, as the first mining project added to the FAST-41 process, which is focused on supporting informed decision-making while reducing and eliminating unnecessary and costly delays associated with projects.

Epiroc’s Erik Svedlund: ‘the answer…is always electrification’

Not a financial report goes by without Epiroc referencing its electrification offering. Whether it be new products, an uptick in customer demand or plans to roll out more battery-electric retrofit options for its customer base, ‘going electric’ has become a consistent quarterly theme for the Sweden-based OEM.

Epiroc’s development timeline for battery-electric machines started all the way back in 2012 – the first Scooptram ST7 Battery was produced in 2013 before a 2014 machine trial with Goldcorp’s Red Lake mines department (now owned by Evolution Mining). The Minetruck MT2010 battery-electric vehicle then came along in 2015.

Its electrification roots go back even further though thanks to Atlas Copco’s acquisition of GIA Industri AB in 2011; a transaction that brought the renowned Kiruna electric trucks into the portfolio.

Over this timeframe, Epiroc has also deployed cable-electric large blasthole rigs across the globe, removing diesel from the drilling process at surface mines.

A constant throughout this period has been Erik Svedlund, Senior Zero Emission Manager at Epiroc, who has helped steer the company’s electrification direction from its first generation battery-electric vehicles to the position it is in now: having integrated automation into the battery-electric mix with the Scooptram ST18 SG and, on the retrofit side, having the resources in place to offer mid-life rebuild options to convert its diesel-powered Scooptram ST7, Scooptram ST1030 and Scooptram ST14 loaders, plus its Minetruck MT436 and Minetruck MT42 trucks, to battery-electric vehicles.

Ahead of his keynote presentation at this month’s The Electric Mine 2023 conference in Tucson, Arizona (May 23-25), IM put some questions to Svedlund on the evolution of the market since he started ‘selling’ the electrification concept to stakeholders.

IM: You have been heading up Epiroc’s electrification efforts since 2010; how have you seen the reception to these solutions and developments change in that 13-year period? Has the speed of the transition surprised you?

ES: The speed is both fast and slow; I estimate that we are in the beginning of the steep part of the S-curve. Previously the drive was more on improved safety and health or a lower total cost of ownership. Now I notice a bigger drive towards low-carbon solutions. But the answer to all these focus areas is always ‘electrification’.

IM: Epiroc has some very ambitious targets when it comes to electrifying its fleet – both underground and on surface with drills. Given the various applications you are serving, how are you able to create a platform that can cater to all the specific parameters at mining operations?

ES: Indeed, Epiroc was quite early in developing battery-electric machines and has set very ambitious sustainability targets that go hand in hand with our customer’s targets. Making one or a few models is not too difficult but enabling everything to go electric required us to develop a new technology platform that would allow all models to become electric. This platform has allowed us to scale up to meet our targets.

IM: Is this why you are pursuing so many different development avenues with customers – diesel-electric trucks, battery-trolley, new battery solutions, BEV retrofits, etc?

ES: There is no one silver bullet to solve all models and applications. As a base there will be an energy-efficient electric driveline. However, how to get energy to that machine will vary depending on application. We will need many solutions in the future.

Erik Svedlund, Senior Zero Emission Manager at Epiroc

IM: How important do you see Batteries as a Service (BaaS) being as your BEV rollout accelerates? What level of interest or uptake have you had so far, and do you see the majority of BEV fleet users opting for this?

ES: The majority of our batteries go out with BaaS but not all; some customers like to own their assets. The setup of these agreements may be tailored to the customer’s needs.

IM: The combination of automation and electrification have been spoken about in the last few years as BEVs have started to be rolled out at a faster pace, with the development of your ST14 SG and ST18 SG representing key milestones in this area. Are mining companies continuing to push you to further automate your BEVs and remove all people from the process? What avenues are you pursuing for this in terms of automating the battery swapping process, recommending trolley charging, leveraging BluVein’s dynamic charging solution, etc?

ES: The trend for safer and more efficient operations will continue. Autonomous machines will have to be supported by autonomous chargers. Dynamic or stationary charging will be dependent on the type of machine and application. But we must not forget the solutions we as OEMs introduce must be able to work together with the grid. When it comes to surface mining, we have already seen that automation and electrification are a perfect match. We already have a complete range of cable-electric large blasthole rigs with a large number of drills in operation in all continents, some of which are automated.

IM: Your keynote presentation is titled, ‘The green transition is a material transition.’ Could you explain what is meant by this, and how Epiroc is involved in this material transition as a mining OEM?

ES: Zero-emission vehicles and renewable energy require metals; we in the mining industry have a special responsibility to do our part. Adopting a ‘green mining’ concept will prepare and position our industry as adding value to our solutions.

Erik Svedlund, Senior Zero Emission Manager at Epiroc, will present: ‘Keynote: The green transition is a material transition’ at The Electric Mine 2023 conference in Tucson, Arizona, on May 24 at 9:00-9:30. For more information on this three-day event, head to www.theelectricmine.com

Arizona Sonoran Copper hires Ausenco for Cactus and Parks/Salyer project PFS

Arizona Sonoran Copper Company says it has engaged Ausenco as lead engineer to deliver an integrated prefeasibility study (PFS) at the Cactus and Parks/Salyer project, in Arizona, USA, by early 2024.

The project, on private land, is a brownfields site with in-place infrastructure and is accessible via highway.

Additionally, the company is pleased to announce the appointment of Victor Moraila as Chief Engineer, joining as the company transitions into a US-based copper developer.

Ausenco will initially review the Cactus draft PFS and incorporate into the new re-scoped PFS, which includes Parks/Salyer. The study will explore a simple heap leach operation, targeting a potential of 50,000 tons (45,359 t) per annum of LME Grade A Copper Cathode from an on-site solvent extraction/electrowinning (SX/EW) plant.

Mineralised material will be sourced from four deposits initially, including Stockpile, Cactus East, Parks/Salyer and Cactus West.

Pending a successful metallurgical program with Rio Tinto’s Nuton Technologies, and a subsequent commercial agreement, the company and Ausenco will layer in the primary sulphides as a fifth source of mineralised material for the SX-EW plant.

Back in July, Arizona Sonoran announced it had entered into a one-year exclusivity period with Nuton™, a Rio Tinto Venture that, at its core, is a portfolio of proprietary copper leach related technologies and capability. The sulphide potential is not included in the 2021 Cactus preliminary economic assessment, which contemplated a simple heap leach and SX-EW operation over an 18-year mine life, producing an average of 28,000 t/y of LME Grade A copper cathode.

In addition to its own technical staff, Ausenco will lead a technical consultant team comprised of Samuel Engineering, AGP Mining Consultants, Stantec, MineFill Services, Clear Creek Associates and Call & Nicholas Inc.

As part of the PFS work for the project, the company and Ausenco have agreed to complete trade-off and optimisation studies and detailed mine production scenario analysis, in conjunction with AGP Mining, around the following areas:

  • Mineralised material sources from an open-pit expansion (Cactus West), underground development (Cactus East and Parks/Salyer), and the existing stockpile;
  • Ore handling, storage, and agglomeration;
  • Leach pad design and operation;
  • Acid storage, consumption and handling;
  • Solvent extraction and electro-winning;
  • Existing and new infrastructure (as required);
  • Preliminary design of access roads in coordination with mine access roads;
  • Preliminary design and location of mine support facilities; and
  • Mine and geotechnical design.

A PFS detailing the oxide and enriched mineralised material is projected to take approximately 10 months to complete, with results currently expected in the December quarter of 2023. Based on the results of current metallurgical testing with Nuton, layering in the primary sulphide material into the mine plan would extend delivery into early 2024.

George Ogilvie, ASCU President and CEO, said: “As Arizona Sonoran Copper Company emerges as a mid-tier copper developer, we are thrilled to welcome the depth of experiences of both Victor and Ausenco; each rooted in quality and value-driven projects. Looking forward, Arizona Sonoran Copper Company is bolstering the technical services team, necessary team to deliver domestically produced copper into the US copper supply chain, from the third largest independent copper deposit in the US.”

Freeport furthers its leading copper leaching excellence

Among the new applications, technologies and data analytics Freeport-McMoRan is advancing as part of a plan to improve copper recovery from its leach processes in North and South America is Jetti Resources’ patented catalytic technology, the company has confirmed to IM.

In its December quarter and 2022 annual results, released late last month, the leading copper miner said it believed the leach innovation initiatives it was pursuing provided potential opportunities to produce incremental copper from its large existing leach stockpiles and lower-grade material currently classified as waste.

The company has been exploring the potential for incremental low-cost additions to its production and reserve profile for some time, saying in the latest results release that it had identified opportunities to achieve an annual run rate of 200 MIb/y (90,718 t/y) of copper through these initiatives by the end of 2023.

Freeport has a long history of copper leaching production with its Americas division, which includes assets such as Morenci and Cerro Verde, having developed and implemented industry-leading technologies for leaching of oxide ores.

The company has been pursuing internal and external initiatives to expand this leading position, focusing on traditional ores and sulphide orebodies that have been typically considered difficult to leach, like chalcopyrite.

This is where Jetti’s technology comes in.

The Colorado-based company has developed catalytic technology to allow for the efficient and effective heap and stockpile leach extraction of copper. This bolts onto existing solvent extraction/electrowinning (SX/EW) leaching plants so it can be deployed rapidly with limited capital expenditure and, because it uses no heating or grinding, has low operational costs. In addition, there are huge environmental benefits from using leaching over pyrometallurgy, according to Jetti.

A Freeport spokesperson confirmed to IM that the company was in a trial of the Jetti technology through “a commercial installation” at its Bagdad mine in Arizona, USA. This mine is one of its major leaching test hubs, with the company targeting over 3 MIb/y of incremental copper cathode production from the open-pit copper mine through this work.

Bagdad has a 77,100 t/d concentrator that produces copper and molybdenum concentrate, an SX/EW plant that can produce approximately 6 MIb/y of copper cathode from solution generated by low-grade stockpile leaching, and a pressure-leach plant to process molybdenum concentrate.

The spokesperson added: “There is potential to expand production via the treatment of additional stockpiles at Bagdad in the future based on results.”

The use of Jetti’s technology is one of several leaching initiatives the company is pursuing – some with outside vendors, some using its own technology and some with joint venture partners.

All of these are focused on not only adding low-cost production to Freeport’s large production base, but also achieving a lower carbon footprint.

Jetti, which Freeport is an investor in, has been conducting a carbon footprint study and Life Cycle Assessment (LCA) of its technology, with the LCA including analyses of typical copper mining operations without Jetti’s technology and a mining operation with Jetti’s technology installed. The LCA is being conducted in conformance with the ISO 14040/44 standard and will be critically reviewed by an independent expert.

Jetti Resources has developed catalytic technology to allow for the efficient and effective heap and stockpile leach extraction of copper

Jetti has also committed to starting to track water usage and waste at all its operations and sites, which includes the installation it has at Capstone Copper’s Pinto Valley operation, also in Arizona.

At Capstone’s operation, Jetti technology is being used extensively as part of a plan to recover up to 350 MIb of cathode copper over the next two decades from historic and new mineralised waste piles.

Teck Resources has also taken an interest in Jetti’s technology having signed an agreement for the evaluation of the solution at a number of Teck’s assets with potential copper resources outside of existing mine plans. BHP, through its BHP Ventures arm, is also an investor in Jetti.

As to Freeport’s wider leaching plans, it said it was looking to use data analytics to provide new insights to drive additional value, while new applications to retain the heat in the stockpiles were “yielding results”.

The company has assessed that it has some 38,000 MIb of contained copper in leach stockpiles deemed “unrecoverable” by traditional leach methods. Of this amount, about 50% is from the massive Morenci mine, which already has leaching production capacity of 900 MIb/y of copper.

Excelsior Mining to explore Nuton leaching options at Johnson Camp mine

Excelsior Mining says it has entered into a collaboration agreement with Nuton LLC, a Rio Tinto venture, to evaluate the use of its Nuton copper heap leaching technologies at Excelsior’s Johnson Camp mine in Cochise County, Arizona, USA.

Rio Tinto has developed the Nuton technologies, an extensive portfolio of advanced copper heap leaching technologies targeted at primary sulphde minerals (including lower-grade minerals), which could not otherwise be processed using traditional leaching or sulphide processing technologies. These technologies offer the potential to produce additional copper in a cost-effective manner that has significant environmental benefits and reduces waste from new and ongoing operations.

The agreement with Excelsior adds to similar pacts Nuton has signed with Regulus Resources, McEwen Copper, Lion Copper and Gold Corp and Arizona Sonoran Copper Company.

The first stage of the collaboration involves Nuton completing certain test work on materials collected from the company’s Johnson Camp mine project to confirm that suitable conditions exist to deploy the Nuton technologies. Assuming this test work is successful, the parties would then work toward negotiating commercial terms for a full-scale deployment of the Nuton technologies at the Johnson Camp mine.

Test work is expected to commence during the March quarter of 2023 with a view toward potentially negotiating commercial terms dependent on the test results and other factors during the September quarter of 2023.

Excelsior is a mineral exploration and production company that owns and operates the Gunnison copper project in Cochise County, Arizona. The project is an in-situ recovery copper extraction project permitted to 125 million pounds (56,699 t) per year of copper cathode production. Excelsior also owns the past producing Johnson Camp Mine and a portfolio of exploration projects, including the Peabody Sill and the Strong and Harris deposits.

Taseko Mines using innovation to increase production and efficiencies

The Taseko Mines story is indicative of the current environment miners find themselves in – maximise productivity to grow margins at existing operations or invest in innovative new methods of extracting critical metals that come with a reduced footprint.

The Vancouver-based company is pursuing both options at the two main assets on its books – the Gibraltar copper mine in British Columbia, Canada, and its Florence Copper project in Arizona, USA.

Gibraltar, owned 75% by Taseko, initially started up in 1972 as a 36,000 t/d operation. It was shut down in 1998 due to low copper prices before Taseko restarted it in 2004. In the years since, the company has invested over $800 million in the mine, increasing the throughput rate to 85,000 tons per day (77,111 t/d), where it’s been operating at since 2014.

The asset now sits as the second largest open-pit copper mine in Canada – with life of mine average annual production of 130 MIb (59,000 t) of copper and 2.5 MIb of molybdenum.

Stuart McDonald, President and CEO of the company, says the company continues to work on the trade-off of upping throughput – potentially past the nameplate capacity – and improving metallurgical recoveries at the operation.

This became apparent in the latest quarterly results, when Taseko reported an average daily throughput of 89,400 tons/d over the three-month period alongside “higher than normal” mining dilution.

The company believes Gibraltar can improve on both counts – mill throughput and mining dilution.

“We were optimistic coming into the new pit (Gibraltar Pit) that, based on the historical data, we could go above 85,000 tons/d as we got settled in and mined the softer ore,” McDonald told IM. “We still believe there are opportunities to go beyond that level, but, at some point, it becomes an optimisation and trade-off between throughput and recoveries.

“In our business, we’re not interested in maximising mill throughput; we’re interested in maximising copper production.”

On the dilution front, McDonald believes the problem will lessen as the mining moves to deeper benches in the Gibraltar Pit.

“As we go deeper, the ore continuity improves, so we hope the dilution effect will continue to improve too,” he said.

“The dilution rate is still not quite where we want it to be, so it’s a matter of looking at our operating practices carefully and following through a grade reconciliation process from our geological model through to assays from our blast holes, assays into the shovel bucket and all the way through to the mill.”

‘Assays into the shovel bucket’?

McDonald explained: “We do use ShovelSense® technology on two of our shovels, so that helps us assess the grade of the material in the shovel bucket.”

To this point, the company has leveraged most value from this XRF-based technology, developed by MineSense, when deployed on shovels situated in the boundaries between ore and waste. This offers the potential to reclassify material deemed to be ‘waste’ in the block model as ‘ore’ and vice versa, improving the grade of the material going to the mill and reducing processing of waste.

ShovelSense has been successful in carrying out this process with accuracy at other copper mines in British Columbia, including Teck Resources’ Highland Valley Copper operations and Copper Mountain Mining’s namesake operation.

McDonald concluded on this grade reconciliation process: “We just have to make sure we are tracing the material through all of those steps and not losing anything along the way. Gibraltar is a big earthmoving operation, so we must continue to keep the material flowing as well as look at the head grade.”

A different type of recovery

In Arizona at Florence Copper, Taseko has a different proposition on its hands.

Florence is a project that, when fully ramped up, could produce 40,000 t of high-quality copper cathode annually for the US domestic market.

It will do this by using a metal extraction and recovery method rarely seen in the copper space – in-situ recovery (ISR).

The planned ISR facility consists of an array of injection and recovery wells that will be used to inject a weak acid solution (raffinate – 99.5% water, 0.5% acid) into copper oxide ore and recover the copper-laden solution (pregnant leach solution) for processing into pure copper cathode sheets. The mine design is based on the use of five spot well patterns, with each pattern consisting of four extraction wells in a 100 ft (30.5 m) grid plus a central injection well. This mine outline and associated infrastructure comes with a modest capital expenditure figure of $230 million.

The company has been testing the ISR technology at Florence to ensure the recovery process works and the integrity of the wells remains intact.

Since acquiring Florence Copper in November 2014, Taseko has advanced the project through the permitting, construction and operating phase of the Phase 1 Production Test Facility (PTF). The PTF, a $25 million test facility, consists of 24 wells and the SX/EW plant. It commenced operations in December 2018.

Over the course of 18 months, Taseko evaluated the operational data, confirmed project economics and demonstrated the ability to produce high-quality copper cathode with stringent environmental guidelines at the PTF, the company says.

McDonald reflected: “We produced over 1 MIb [of copper] over this timeframe and then switched over from a copper production cycle into testing our ability to rinse the orebody and restore the mining area back to the permitted conditions.

“We’re proving our ability to do the mining and the reclamation, which we think is a critical de-risking step for the project.”

Over an 18-month period, Taseko produced 1 MIb from the ISR test facility at Florence

Taseko says Florence Copper is expected to have the lowest energy and greenhouse gas-intensity (GHG) of any copper producer in North America, with McDonald saying the operation’s carbon footprint will mostly be tied to the electricity consumption required.

“Our base case is to use electricity from the Arizona grid, which has a combination of renewables, nuclear and gas-fired power plants,” he said. “In the longer-term, there are opportunities at Florence to switch to completely 100% renewable sources, with the most likely candidate being solar power.

“At that point, with renewable energy powering our plant, we could be producing a copper product with close to zero carbon associated with it.”

Gibraltar has also been labelled as a “low carbon intensity operation” by Skarn Associates who, in a 2020 report, said the operation ranked in the lowest quartile compared with other copper mines throughout the world when it comes to Scope 1 and 2 emissions.

When it comes to the question of when Florence could start producing, Taseko is able to reflect on recent successful permitting activities.

In December 2020, the company received the Aquifer Protection Permit from the Arizona Department of Environmental Quality, with the only other permit required prior to construction being the Underground Injection Control (UIC) permit from the US Environmental Protection Agency (EPA).

On September 29, the EPA concluded its public comment period on the draft UIC it issued following a virtual public hearing that, according to Taseko, demonstrated strong support for the Florence Copper project among local residents, business organisations, community leaders and state-wide organisations. Taseko says it has reviewed all the submitted comments and is confident they will be fully addressed by the EPA during its review, prior to issuing the final UIC permit.

Future improvements

In tandem with its focus on permitting and construction at Florence, and upping performance at Gibraltar, the company has longer-term aims for its operations.

For instance, the inclusion of more renewables to get Florence’s copper production to carbon-neutral status could allow the company to benefit from an expected uptick in demand for a product with such credentials. If the demand side requirements for copper continue to evolve in the expected manner, it is easy to see Taseko receiving a premium for its low- or no-carbon product over the 20-year mine life.

At Gibraltar, it is also pursuing a copper cathode strategy that could lead to the re-start of its SX-EW plant. In the past, this facility processed leachate from oxide waste dumps at the operation.

“As we get into 2024, we see some additional oxide ore coming out of the Connector Pit, which gives us the opportunity to restart that leach operation and have some additional pounds coming out of the mine,” McDonald said.

Alongside this, the company is thinking about leaching other ore types at Gibraltar.

“There are new technologies coming to the market in terms of providing mines with the opportunity to leach sulphides as well as oxides,” McDonald said. “We’re in the early stages of that work, but we have lots of waste rock at the property and, if there is a potential revenue stream for it, we will look at leveraging that.”