Tag Archives: Arizona

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.”

GroundProbe chooses Tucson for location of second manufacturing facility

GroundProbe has announced plans to build a second dedicated manufacturing facility in Tucson, Arizona, USA, marking a new chapter in its commitment to better serve its customers in the Northern hemisphere.

The expansion of GroundProbe’s manufacturing capabilities comes following significant growth in recent years.

Announcing its plans at the recent International Slope Stability Symposium in Arizona, GroundProbe CEO, David Noon, said the new facility will open its doors in early 2023.

“As our global footprint and customer base continues to grow, so too does the volume and variety of products that we produce,” he said. “We saw it as an absolute necessity to bolster our offering and extend our manufacturing capability from Asia Pacific to the Americas.

“It means that, from early 2023, we will be able to more readily deploy our safety-critical systems – systems that are integral to their ongoing operations and productivity – to our Northern hemisphere customers.”

GroundProbe, which currently manufactures its products in Australia, says it is widely accepted as the global leader in real-time technologies that detect instabilities and predict when mine and dam collapses will occur.

The addition of a second manufacturing facility signifies an important step for GroundProbe’s future growth, especially for North and South America, for GroundProbe’s Chief Commercial Officer and VP Americas, Ben Moke.

“When scouting locations for a second site, Tucson quickly became the preferred location,” Moke said. “It’s central to our customers, and it’s close to a number of geotechnical consulting firms and university partners, including the Geotechnical Center of Excellence at the University of Arizona.

“It’s going to be fantastic to have a facility where the geotechnical community can experience our state-of-the-art technology being manufactured and deployed to mine sites across the Americas. With a track record that speaks for itself, GroundProbe’s technologies are the industry’s most robust and reliable, having never failed to detect a collapse.

“The second facility will manufacture every one of our products to the same level of quality that we are known for and that is expected of us as market leaders.”

Cemvita Factory and Arizona Lithium collaborate on bio-lixiviant production tech testing

Cemvita Factory and Arizona Lithium Limited have announced the signing of a broad Letter of Intent (LOI) encompassing Cemvita installing a bio-lixiviant production facility at AZL’s Lithium Research Center in Tempe, Arizona.

With this facility, Cemvita will perform pilot testing on both tank and heap bioleaching for lithium extraction from clay or sedimentary materials.

Using industrial biotechnology, Cemvita intends to revolutionise the mining industry and lower the environmental footprint of mining.

Cemvita’s Biomining team works with companies to optimise existing bioprocesses and develop new methods in mineral processing and extractive metallurgy to lower the energy and carbon intensity of the mining industry and enable extraction of the minerals needed for a renewable energy future, it says. Processes that can be enhanced by the latest industrial biotech apply across the entire mining supply chain including mining and mineral pre-processing, in-situ recovery, leaching, beneficiation, remediation and recycling.

Carbon intensity of lithium from sedimentary resources is expected to be substantially lower than hard-rock operations, and with a lower water use footprint compared with brine resources.

“Cemvita’s natural organic extraction technology takes sustainability further, opening the opportunity for even lower cost operations such as heap and in-situ leaching,” the company said. “Heap and in-situ leaching provide a substantially lower physical, chemical and energy footprint.”

Cemvita’s Vice President Mining Biotech, Marny Reakes, said: “This pilot work in Arizona is a great step forward in our drive to both reduce the footprint of mining and unlock the mineral resources that are crucial for our planet’s renewable energy future.”

AZL and Cemvita also plan to work towards deploying this technology for in-situ mining. This process aims to eliminate much of the ground disturbance and waste generation associated with typical mining operations.

Charles Nelson, Chief Business Officer of Cemvita, said: “Our goal is to enable the most environmentally friendly end-to-end process of mining lithium through the application of our technology. This includes utilising cleaner methods of extraction with the option of layering Cemvita’s other beneficial technologies, such as CO2 based fuels and decarbonising processing, in the mining space.”

Arizona Lithium’s Research Center, located in Tempe, is a facility designed as a commercial pilot to allow both AZL and third-party producers to take large volumes of ore from their prospective mines and test all components of the processing of the ore through the production of various grades of battery-grade lithium materials. The facility is planned to be in operation in early 2023.

AZL Managing Director, Paul Lloyd, said: “We are very pleased to have signed this partnership with Cemvita. We are focused on our responsibility to our shareholders and to the environment, and believe that both of these stakeholders will greatly benefit from the successful implementation of Cemvita’s technology. We aim to be a model for sustainable development, and be the pioneer for Lithium producers to use technology like Cemvita’s. We are excited to see the results of the partnership start to show in the next three-to-six months at which time we will assess further partnership potential.”

AZL is currently focused on the Big Sandy project in Arizona, which is characterised largely by flat-lying basin sediments comprising predominantly of analcime and potassic alteration zones. The green lacustrine lithium bearing horizon is traceable for over 11 km from north to south and extends at least 2 km to the east as a flat sheet at or near surface, according to the company.

South32 making engineering and design headway at Hermosa project

A stellar set of annual financial results has provided the ideal backdrop for South32 to update shareholders on its rapidly progressing Hermosa project in Arizona, USA.

Released late last month, the company’s 2022 financial year results showed off record earnings of $2.6 billion, record free cash flow from operations of $2.6 billion and record return on invested capital of 30.1%.

With group copper-equivalent production expected to increase by 14% in the next financial year, South32 looked to be well leveraged to in-demand metal markets at the right time.

The company has progressively been repositioning its portfolio toward metals critical for a low-carbon future, having already established a pipeline of high-quality development options. One of these high-quality development options is Hermosa.

Hermosa, which the company acquired outright back in 2018 as part of a takeover of Arizona Mining, is key to the company’s critical metals pursuit, having exposure to base and battery metals that are expected to grow in demand – both domestically in the US and internationally.

It is being designed as South32’s first ‘next generation mine’, according to Hermosa President, Pat Risner, with a series of technical reports highlighting its use of automation and technology to minimise its impact on the environment and target a carbon-neutral mining scenario in support of the group’s goal of achieving net zero operational greenhouse gas emissions by 2050.

These same reports also highlighted the potential to develop a sustainable, low-cost operation producing zinc, lead and silver from the Taylor deposit, with the bonus of possible battery-grade manganese output for rapidly growing domestic markets from the Clark deposit.

In the latest results, the company said it was devoting $290 million of growth capital expenditure in the 2023 financial year to progressing Hermosa as it invests in infrastructure to support critical path dewatering and progress study work for the Taylor Deposit. This is ahead of a planned final investment decision expected in mid-2023, which should coincide with the feasibility study.

South32 is devoting $290 million of growth capital expenditure in the 2023 financial year to progress Hermosa

Some $110 million of this was assigned to construction of a second water treatment plant (WTP2) to support orebody dewatering at the asset, alongside dewatering wells, piping systems and dewatering power infrastructure.

An additional $95 million was slated for engineering and initial construction ahead of shaft sinking at the operation, plus work to support power infrastructure and road construction.

The remaining amount was expected to support work across the broader Hermosa project, including Clark study costs and the Taylor feasibility study.

All signs from these results are that the company is laying the groundwork to develop this project ahead of that mid-2023 deadline.

In another sign of progress, South32 recently signed a “limited notice to proceed” for shaft engineering and design at Hermosa with contractor Redpath, Risner confirmed, adding that the award represented a positive step forward for the project.

“We look forward to continuing our engagement with local communities and all of our stakeholders as we make further progress with the project,” he said.

Redpath will no doubt be evaluating the technical studies that have been signed off to this point and informing future reports.

The PFS design for Taylor is a dual shaft mine which prioritises early access to higher grade mineralisation, supporting zinc-equivalent average grades of approximately 12% in the first five years of the mine plan. The proposed mining method, longhole open stoping, is similar to that used at Cannington, in Australia, and maximises productivity and enables a single stage ramp-up to the miner’s preferred development scenario of up to 4.3 Mt/y.

Yet, the Clark deposit opportunity – which has become even more tantalising with the US Government invoking the Defense Production Act and supporting the production of critical metals including manganese – could see the plan change.

The company says it may accelerate the prefeasibility study for the Clark deposit, which is spatially linked to the Taylor deposit. A scoping study has previously confirmed the potential for a separate, integrated underground mining operation producing battery-grade manganese, as well as zinc and silver from the deposit.

South32 previously said Clark has the potential to underpin a second development stage at Hermosa, with future studies to consider the opportunity to integrate its development with Taylor, potentially unlocking further operating and capital efficiencies.

With a PFS selection study expected later this year, investors and interested parties will soon know the role Clark could play in the wider Hermosa project.

What is easy to gauge already is that Hermosa is progressing on a track that many other development projects in in-demand sectors have gone down.

Rio Tinto signs pact to test Nuton copper heap-leach tech on Cactus primary sulphides

US-based copper developer and near-term producer, Arizona Sonoran Copper Company Inc, has 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 exclusivity was triggered by successfully modelling the Cactus and Parks/Salyer ore samples and achieving the previously contemplated indicative metallurgical recoveries of at least 72% (copper recovery to cathode), which included chalcopyrite, under an investor rights agreement, Arizona Sonoran said.

Nuton will continue to test the application of its copper heap-leach related technology to the primary sulphide component of the Cactus Mine and Parks/Salyer Projects, in Arizona, through column leaching and scoping out capital and operating costs and design parameters, it added.

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.

Within the current Cactus project resource base is a primary sulphide mineral resource of 77.9 million short tons (70.7 Mt) at 0.35% CuT (indicated) and 111.2 million short tons at 0.35% CuT (inferred).

George Ogilvie, Arizona Sonoran President and CEO, said: “The Nuton preliminary work results indicate optionality for unlocking the substantial primary resource at Cactus, which is currently stranded at the bottom of the pit. Although we are in the early stages of testing chalcopyrite recoverability on an economic basis, we are encouraged by the initial results and the significant potential to continue building scale at Cactus and potentially at Parks/Salyer in the longer term.”

The preliminary metallurgical testing program covered ore sample selection, preparation and mineralogical characterisation to produce CFD modelling results providing early-stage indicative recoveries in respect of various ore types and specifically the chalcopyrite ore at Cactus. Further test work underway covers test column leaching and scoping out capital and operating costs and design parameters, the company said.

Nuton is an innovative new venture that aims to help grow Rio Tinto’s copper business. At its core is a portfolio of proprietary copper leach related technologies and capability – a product of almost 30 years of research and development. The Nuton technologies offer the potential to economically unlock known low-grade copper sulphide resources, copper bearing waste and tailings, and achieve higher copper recoveries on oxide and transitional material, allowing for a significantly increased copper production outcome, according to Rio. One of the key differentiators of Nuton is the potential to deliver leading environmental performance, including more efficient water usage, lower carbon emissions, and the ability to reclaim mine sites by reprocessing mine waste, it claims.

Hudbay’s Constancia continuous improvement quest leads to MineSense XRF trial

Hudbay Minerals has one of the lowest cost per tonne copper sulphide operations in Peru on its hands at Constancia, but it is intent on continuously improving the mine’s margins and environmental performance through a commitment to continuous improvement. This has recently led it to exploring the potential of sensor-based ore sorting.

Hudbay’s operations at Constancia include the Constancia and Pampacancha pits, an 86,000 t/d ore processing plant, a waste rock facility, a tailings management facility and other ancillary facilities that support the operations.

The company increased reserves at the mine, located in the Cusco department, by 33 Mt at a grade of 0.48% Cu and 0.115 g/t Au last year – an increase of approximately 11% in contained copper and 12% in contained gold over the prior year’s reserves.

With the incorporation of Pampacancha and Constancia North, annual production at Constancia is expected to average approximately 102,000 t of copper and 58,000 oz of gold from 2021 to 2028, an increase of 40% and 367%, respectively, from 2020 levels, which were partially impacted by an eight-week temporary mine interruption related to a government-declared state of emergency.

Constancia now has a 16-year mine life (to 2037) ahead of it, but the company thinks there is a lot more value it can leverage from this long-life asset and it has been looking at incorporating the latest technology to prove this.

In recent years it has, for instance, worked with Metso Outotec to improve rougher flotation performance at Constancia using Center Launders in four e300 TankCells and installed a private LTE network to digitise and modernise its open-pit operations.

Peter Amelunxen, Vice President of Technical Services at Hudbay, said the Constancia ore sorting project – which has seen Hudbay partner with MineSense on a plan to trial the Vancouver-based cleantech company’s ShovelSense X-ray Fluorescence (XRF)-based sorting technology – was one of many initiatives underway to further improve the operating efficiency at Constancia.

“The ore sorting program is separate from the recovery uplift program at Constancia,” Amelunxen said, referring to a “potentially high-return, low capital opportunity” that could boost milled copper recovery by 2-3%.

He added: “The ore sorting program is expected to yield positive results at the mining phase of the operation and is expected to increase the mill head grade and reduce metal loss to the waste rock storage facility.”

Back in April 2021 during a virtual site visit, Hudbay revealed it was trialling bulk sorting at Constancia as one of its “optimisation opportunities”, with Amelunxen updating IM in mid-January on progress.

Hudbay has previously evaluated particle sorting at its Snow Lake operations in Manitoba – with the benefits outlined in a desktop study “muted” given “bottlenecks and constraints”, Amelunxen said – but, at Constancia, it considered XRF sorting from the onset for copper-grade only pre-concentration, due to its perception that this application came with the lowest potential risk and highest probability of success.

The company has a three-phase evaluation process running to prove this, with phase one involving a “bulk sorting amenability study”, phase two moving up to laboratory-scale testing and phase three seeing trials in the field.

The “bulk sorting amenability study” looked at downhole grade heterogeneity to estimate curves of sortability versus unit volume, Amelunxen detailed. Laboratory testing of drill core samples to evaluate the sensor effectiveness was then carried out before an economic analysis and long-range-plan modelling was conducted.

With the concept and application of bulk sorting having cleared all these stage gates, Hudbay, in November, started pilot testing of XRF sensors on a loader. This involved fitting a ShovelSense unit onto the 19 cu.m bucket of a Cat 994H wheel loader, with around 20 small stockpiles of “known grades” loaded onto the bucket and dispatched into a feeder and sampling system (pictured below, credit: Engels Trejo, Manager Technical Services, Hudbay Peru). With this process completed, the company is now awaiting the results.

At a similar time, the company moved onto demonstration trials of a “production” ShovelSense sensor unit on the 27 cu.m bucket of a Hitachi ECX5600-6 shovel operating in one of the pits. It has collected the raw spectral data coming off this unit since the end of November, with plans to keep receiving and analysing sensor data through to next month.

“We should have the finalised XRF calibration in February, at which time we’ll process the raw data collected during the three-month trial period and compare it with the short-term mine plan (ie grades of ore shipped),” Amelunxen said. “So, by the end of February or early March, we’ll be able to validate or finetune the economic model.”

Should the results look favourable, Amelunxen is confident that leasing additional sensors and installing them on the other two Hitachi ECX5600-6 shovels will not take long.

Credit: Engels Trejo, Manager Technical Services, Hudbay Peru

“Plans may change somewhat as the program unfolds,” he said. “For example, we may have success sorting ore, but feel additional calibration is required for waste sorting at Pampacancha, in which case we may install production sensors on Constancia ores while doing another trial program at Pampacancha.

“It all depends on the precision of the XRF calibration.”

Higher head grades and potentially higher copper recoveries may be the headline benefits of using ore sorting technology, but Hudbay is equally focused on obtaining several key environmental benefits, including reduced consumption of energy and water.

On the latter, Amelunxen said: “This is expected due to the processing of less ‘waste’ by removing uneconomic material earlier in the process and reducing the hauling and processing costs of the uneconomic material.”

Looking even further forward – past a potential commercial implementation of XRF-based ore sorting at Constancia – the company plans to evaluate the application of other sensors, too.

“For our future development copper project in Arizona, we plan to look at other sensors as well,” Amelunxen said, referencing the company’s Rosemont asset.

This ore sorting project is not the only project the processing team at Constancia are examining, as Amelunxen already hinted at.

As part of the recovery uplift project, it is installing equipment that will allow the operation to increase the overall mass recovery of the roughers, which is currently constrained by the downstream pumps and cleaning circuit.

“This will allow us to achieve an expected 2-3% increase in copper recoveries without impacting concentrate grade,” Amelunxen said.

It has various initiatives underway under the “Moly plant improvement projects” banner, too. This includes flowsheet optimisation, pH control in the cleaners and pH reduction in the bulk cleaners.

“This project has been in the works since late 2019, and the new mechanical agitator installation in the cleaning cells was completed during the August 2021 schedule mill maintenance shutdown and the new nitrogen plant was commissioned in the second half of the year,” Amelunxen explained. “The next steps are pH control in the cleaners (with CO2), water balance optimisation and potentially installing a Jameson flotation cell as a pre-rougher (the cell is already on site and not in use, it will be repurposed pending results of the pH trials).”

A flotation reagent optimisation study is also on the cards, aimed at reducing zinc and lead contamination in the copper concentrate.

“A depressant addition system is on the way to site and should be installed in February, with plant trials commencing in March,” Amelunxen said, explaining that this followed laboratory test work completed in 2021.

Resolution Copper, Stantec leverage hydropanel tech to provide new clean water source for locals

Native American communities in eastern Arizona, USA, look set to benefit from a new source of clean drinking water through a project sponsored by Resolution Copper and Stantec to deploy innovative renewable “hydropanel” technology, the mine developer says.

Resolution Copper and Stantec are partnering with White Mountain Apache community members to provide 64 hydropanels on the Fort Apache Reservation and supporting hydropanel installation programs in other Native American communities.

White Mountain Apache Tribe District II Councilman, Jerold Altaha, said: “Water is valuable; it’s the life force of humanity. Thanks to this wonderful opportunity with Resolution Copper, our community of Carrizo will have access to safe, clean drinking water. Due to high levels of manganese in the main water wells, our community has had to depend on portable water tanks as a means to obtain drinking/cooking water for years. The hydropanels will now enable us to draw water from the air which will provide up to 10 litres of water or about 20 16 oz bottles a day, at no cost to the family. We are grateful for these opportunities which continue to make a difference in everyday life for our people and community.”

Stantec Water Business Operating Unit Leader, John Take, added: “We are proud to be a part of this effort to provide safe, reliable drinking water to the Native American communities in eastern Arizona. Innovative and renewable methods such as the hydropanel technology are playing an increased role in helping solve these complex problems in a sustainable manner.”

Hydropanels are a one-of-a-kind renewable water technology that uses the solar energy to provide a safe and consistent supply of drinking water by drawing pure, constantly replenished water vapour out of the sky, according to Resolution Copper. The self-contained system converts water molecules in the air into liquid water, which is collected and mineralised in a reservoir inside the panel, creating high-quality drinking water that can be delivered directly to homes, businesses, and community distribution centres.

Resolution Copper Project Director, Andrew Lye, said: “Water is a fundamental resource, and many members of our neighbouring Tribes do not have reliable access to safe drinking water. Projects like the hydropanel deployment will help alleviate some of the burden, and make a difference where it matters most. Resolution Copper continues to look for ways in which we can work in partnership to be part of the solution and support the communities around us.”

So far, Resolution Copper has invested nearly $2.8 million through partnerships and donations to projects with Native American Tribes and other communities in the Copper Corridor in 2021.

The Resolution Copper project is a proposed underground mine 96 km east of Phoenix, Arizona, near the town of Superior. The project is a joint venture owned by Rio Tinto (55%) and BHP (45%).

To date, more than $2 billion has been spent to develop and permit the project, including reclamation of the historic Magma Copper Mine site, sinking a second shaft to mining depth, rehabilitating an existing shaft and deepening to mining depth, extensive drilling and orebody testing, and the federal approval and public engagement process.

Taseko Mines starts commercial construction move at Florence ISR copper project

Taseko Mines, having just completed a $400 million bond refinancing and fundraising program, is moving forward with developing a commercial operation at its Florence in-situ recovery (ISR) copper project in Arizona, USA.

Capital requirements for the commercial production facility at Florence, which followed an ISR pilot project, are estimated at $230 million.

Pending final regulatory approvals and financing, Taseko has previously stated it could start construction of the commercial operation this year, with first production in late 2022.

Stuart McDonald, President of Taseko, said: “With the majority of the required funding for our Florence Copper project now in hand, we are moving forward with final design engineering of the commercial production facility as well as procurement of certain critical components.”

McDonald said the company is continuing to advance discussions with potential joint venture partners at Florence, but its strong cash balance and improved Gibraltar mine cash flows from copper prices currently over $3.70/Ib ($8,159/t) means it has “numerous options available” to obtain the remaining funding.

Russell Hallbauer, CEO of Taseko, added on Florence: “Florence is one of the least capital-intensive copper production facilities in the world and, when fully ramped up, will produce 40,000 t of high-quality cathode copper annually for the US domestic market.

“It is a green project, with carbon emissions and water and energy consumption all dramatically lower than a conventional mine, and, with C1 operating costs of $0.90/Ib of copper, it will also be in the lowest quartile of the global cost curve.”

Capstone considering Eriez HydroFloat tech to boost Pinto Valley performance

Capstone Mining is continuing to leverage innovative, low-cost technology at its Pinto Valley mine in an attempt to further utilise its existing solvent-extraction and electowinning (SX-EW) plant at the Arizona, USA, operation.

In the December quarter of 2019, Pinto Valley commenced a PV3 Optimization project designed to achieve safer, more reliable and higher capacity operations without major investments in new comminution equipment. A goal was set to achieve increased reliability, and higher throughput at maximised copper recovery with lower costs by leveraging new inexpensive technologies.

In its September quarter results, the company provided an update on this project, saying, to October 27, it had spent $17 million as part of its Phase 1 developments. This included crushing and mill equipment replacements, which are 60% complete with full completion expected by July 2021.

As part of its Phase 2 developments, Capstone spent $10 million in conveyor, mill auto controls, cyclone packs and tailings thickener upgrades. These upgrades are planned to be completed by the end of the September quarter of 2021.

On top of this, the miner completed a blast fragmentation optimisation project to target 30% fines (minus-0.5 in) in run of mine feed in the June quarter. In the same quarter, it completed a $300,000 tele-remote Cat D10 Dozer project to increase worker safety for high-risk applications. Another $6 million was spent on new mine equipment to increase efficiency while lowering diesel consumption, greenhouse gas emissions and other operating costs by $800,000/y. This project was completed in the September quarter.

In terms of its metallurgical innovation, the company continued to use novel catalytic technology developed by Jetti Resources at Pinto Valley, expected to deliver 300-350 MIb of copper cathode over the next 20 years from high-grade mine waste and historic stockpiles at all-in costs under $2/Ib. This technology uses a catalyst on primary sulphide minerals to disrupt the sulphur metal bond of the mineral and allow for a leaching solution to contact the copper. This enables the extraction of the metal to take place unimpeded.

Capstone also made plans to use new reagents to improve worker safety and improve overall metallurgical performance at its molybdenum plant re-start project. This would involve “minimal capital” and completion was targeted by the March quarter of 2021, it said.

Capstone says it is targeting to reach 60,000-63,000 t average daily throughput at Pinto Valley at an 85-90% recovery by 2022-2023. This is 17-30% higher than 2019 performance and is subject to further test work and studies to be completed in the first half of 2021, including tailings management, the company explained.

Added to this, following positive laboratory results on Pinto Valley flotation circuit samples, Capstone and Eriez are planning to commence pilot plant testing of the HydroFloat technology.

The HydroFloat fluidised bed assisted flotation cell has previously proven effective at floating coarse ore particles, up to two to three times the size limit of conventional flotation cells in commercial applications such as at Newcrest Mining’s Cadia Valley operation in Australia. Newcrest has recently decided to expand the use of this technology at the operation.

Capstone says the lab results at Pinto Valley had led Eriez to report an opportunity to reduce copper losses by up to 50%, thereby boosting overall recovery by up to 6% at Pinto Valley.

“Furthermore, the ability to recover coarse particles could allow for higher mill throughput while achieving high copper recovery,” Capstone said.

Other benefits could be lower grinding costs, lower water and energy consumption and increased tailings stability via coarser tailings.

Pilot testing is due to commence in November with results expected back in the March quarter of 2021.

Lastly, work on PV4 expansion scenarios to take advantage of around one billion tonnes of measured and indicated resources at 0.30% Cu continued during the September quarter.

“Given management’s confidence in PV3 Optimization progress to date, including the successful implementation of the novel catalytic technology from Jetti Resources to enhance leaching performance, Capstone has decided to evaluate expansion scenarios using existing assets rather than building new mill infrastructure,” the company said.

The study is assessing higher mining rates, higher cutoff grades to the mill, and an increased tonnage available for leaching.

While a significant mill expansion is not currently being contemplated, an expansion of Pinto Valley’s SX-EW capacity of 25 MIb/y may be necessary, it said. Extensive column leach test work will be conducted over 2021, with the overall PV4 expansion study expected to be released in 2022, Capstone added.