Tag Archives: Silver

Hycroft Mining continues evaluation of novel sulphide heap oxidation/leach process

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After testing out a “novel” oxidation and leaching process at the Hycroft Mine in Nevada, USA, Hycroft Mining Holding Corp is making plans to go back to a conventional oxide leaching setup in 2021.

The company produced 27,392 oz of gold and 178,836 oz of silver in 2020, an almost three-fold increase over 2019. It hit these numbers while operating at a pre-commercial scale using the novel process, which oxidises sulphides ahead of leaching.

It is now planning for run-of-mine production of 45,000-55,000 oz of gold and 400,000-450,000 oz of silver in 2021 using conventional cyanide heap leach.

It is anticipated that mining in the first four months of 2021 will be performed using the existing Hycroft fleet and a rental fleet, moving approximately 1.5 Mt/mth of ore and waste. For the remainder of the year, Hycroft intends to mine some 500,000 t of oxide and transitional ore and waste per month with a more cost-effective mining fleet.

Diane R Garrett, President & Chief Executive Officer, reflected on the results: “2020 was an important year for Hycroft as the company continued to focus on the restart of the Hycroft Mine. Throughout the year, we advanced work on the proprietary two-stage sulphide heap oxidation and leach process and made several important findings that will need to be addressed prior to our implementing the novel technology on a commercial scale.

“In 2021, we expect to mine predominantly oxide and transition material, which are more economic when treated using a conventional run-of-mine heap leaching method, which gives us the opportunity to continue to refine the operating parameters and flowsheet for the new heap leach pad and novel process. While the company continued to make significant progress in better understanding this proprietary process and its application on a commercial scale, the past year also presented some operational challenges, including learning to navigate in a newly emerged COVID-19 world.”

In the last few months, Hycroft says it has worked alongside consultants to identify and investigate opportunities for improvements in operating parameters for the two-stage sulphide heap oxidisation and leach process. The result of the work to date has identified several items that were not considered or included in the original plan and design but are critical to the success of this process. These findings include:

  • Adding a forced air injection system for the leach pad which is a key component of the oxidation process;
  • Developing a system for segregating solution flows to and from the heap leach pad to avoid co-mingling of solutions among heap lifts and ore processing stages that negatively impact recoveries and conditions on the leach pads;
  • Identifying that the finer crushed material requires agglomeration in order to achieve optimal permeability and gold/silver recoveries;
  • Understanding that higher soda ash, caustic soda, and cyanide consumption will be required which Hycroft experienced throughout the 2020 pre-commercial test pad programs and recently confirmed through the review of the test work;
  • Determining that some transitional ores are more economically attractive when processed as direct leach, run-of-mine material; and
  • Concluding that additional variability metallurgical and mineralogy studies will be required to better understand each of the geometallurgical domains in the orebody. While there was some variability work completed in the past, the recent test work has revealed that additional variability test work and compositing is necessary to fully understand the geometallurgy of each domain, and that additional sampling, including sampling below the water table where the predominance of the sulphide resources exist, is required given the complexity and variability of the large orebody.

The additional variability test work will also include detailed mineralogy studies as it is important to understand the role other minerals may play in the overall oxidation process and to enhance Hycroft’s ability to measure oxidation rates accurately and consistently, it said.

The team at Hycroft has developed an approximate $10 million program for drilling and additional metallurgical and mineralogical studies in 2021. This program of work has been approved by the Board of Directors of Hycroft and can be funded from existing cash and Hycroft’s current operating plans.

Hycroft expects to mine and stockpile at least 300,000 tons (272,155 t) of sulphide ore in 2021 that, once sufficient additional work on the novel process has been completed, will be available for testing to further refine operating parameters and measure its performance for large scale application of the oxidation heap leach.

Garrett added: “2021 is a foundational year designed to advance the work necessary in preparation for larger-scale sulphide operations. The team is working diligently to optimise current and future heap leach mine plans and to evaluate all opportunities for more profitable mine plans in the near and medium term. This work involves taking a ‘ground up’ approach working from the orebody out. The company’s prior plan was developed using a $1,200/oz gold price pit shell which leaves profitable ore behind in the current gold and silver price environment. By running pit shells at recent gold and silver prices, we have identified additional areas of oxide mineralisation that can generate cash flows over the next several years and we have already begun to identify areas of higher-grade mineralisation that will become important for mine sequencing and further improving cash flows prior to accessing sulphide material.”

As the company considers life-of-mine development and planning for the Hycroft deposit, particularly in the current gold and silver price environment, Hycroft says it is prudent to evaluate proven processing technologies for treating some ore types that may be more profitable than only using the two-stage sulphide heap oxidation and leaching process.

Potential opportunities being examined by the company in 2021 include: developing an understanding of the grade range distribution of the sulphide material; completing on-going work on the higher-grade areas of Hycroft; and following up on historical high-grade intercepts.

In order to capitalise on these potential opportunities, which take advantage of the current commodity price environment, Hycroft believes that it should also evaluate the benefits of a multi-process operation. Long-term operating scenarios may include conventional run-of-mine cyanide heap leaching for the oxide and transitional material, sulphide heap oxidation and leaching using the novel process, and an appropriately sized milling and flotation plant for processing the higher-grade ranges of sulphide material.

“The company believes that the plan it has put in place for 2021 will provide the new team the time to fully consider and evaluate these opportunities and make any necessary changes to improve the leach pads, process plants and process flowsheet, maintain and develop its workforce, and advance the project, in order to further enhance the value of the project,” it said. “As the test work advances and alternative processes are considered, the company expects to perform technical studies and trade-off evaluations which may result in an updated feasibility study.”

Rio Tinto Kennecott to recover tellurium from copper smelting

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Rio Tinto is to construct a new plant that will recover tellurium, a critical mineral used in solar panels, from copper refining at its Kennecott mine near Salt Lake City, Utah.

The company is investing $2.9 million to set up the plant, which will recover tellurium as a by-product of copper smelting, extracting a valuable mineral from waste streams. The plant will have a capacity to produce around 20 t/y of tellurium, the miner said.

Rio expects to begin production of tellurium in the December quarter of 2021, creating a new North American supply chain for the critical mineral.

Tellurium is an essential component of cadmium telluride, a semiconductor used to manufacture thin film photovoltaic solar panels. Thin films made of this compound can efficiently convert sunlight into electricity, according to the miner. Tellurium can also be used as an additive to steel and copper to improve machinability, making these metals easier to cut. It can also be added to lead to increase resistance to sulphuric acid, vibration and fatigue.

Rio Tinto Kennecott Managing Director, Gaby Poirier, said: “The minerals and metals we produce are essential to accelerate the transition to renewable energy. Adding tellurium to our product portfolio provides customers in North America with a secure and reliable source of tellurium produced at the highest environmental and labour standards with renewable energy. Rio Tinto is committed to using innovation to reduce waste in our production process and extract as much value as possible from the material that we mine and process.”

Utah Governor, Spencer Cox, said: “With abundant natural resources, Utah is ideally positioned to help supply the critical minerals essential to maintain American manufacturing competitiveness. Rio Tinto’s smelter at Kennecott is one of only two that is capable of producing copper and other critical minerals. The new tellurium plant is another valuable contribution to critical mineral independence and energy security in the US”

Along with producing almost 20% of US copper, Kennecott’s smelting process also recovers gold, silver, lead carbonate, platinum, palladium and selenium, while molybdenum is recovered from the Copperton concentrator. In total, nine products are currently recovered from the ore extracted at Kennecott.

Rio Tinto is a partner with the US Department of Energy’s Critical Materials Institute (CMI) and works closely with CMI experts to discover further ways to economically recover critical mineral by-products such as rhenium, tellurium and lithium. The company is also investing in new facilities to extract battery-grade lithium from waste rock at its Boron, California mine site and high quality scandium oxide from waste streams at its metallurgical complex in Sorel-Tracy, Quebec.

Polymetal 2020 profits rise as it accelerates ESG efforts

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Polymetal recorded a strong set of financials in 2020, with its revenue, adjusted EBITDA and net earnings metrics all benefitting from higher production volumes and commodity prices.

Revenue increased by 28% year-on-year to $2.87 billion, adjusted EBITDA rose 57% to $1.69 billion and net earnings hit a record $1.09 billion in 2020.

The company’s 2020 gold-equivalent output amounted to 1.56 Moz, a 4% increase year-on-year and 4% above the original production guidance of 1.5 Moz. Strong contributions from its Kyzyl, Varvara and Albazino mines offset a planned grade decline at Voro, as well as lower production at Svetloye, the company said.

While production rose, the company’s greenhouse gas emissions intensity reduced by 4%, Polymetal said. It attributed this to energy efficiency initiatives, switching its mining fleet to electric vehicles, a shift from diesel to grid energy sources and green energy contracts.

Back in December, SMT Scharf AG signed an agreement with Polymetal to develop and produce battery-electric powered LHDs and mid-range underground trucks as prototypes for its gold and silver mines, with these units to be delivered to the company by October 2021.

Polymetal’s environmental, social and governance efforts did not stop there.

In 2020, the company invested $29 million at its Omolon hub in the Magadan region of Russia. This capital expenditure was mainly related to the construction of a dry tailings storage facility and engineering and preparatory works for a 2.5 MW solar plant (due to come online this year). This will be joined by another 5-10 MW solar facility at its Kyzyl operation (Kazakhstan) in 2022.

On its other tailings facilities, Polymetal said: “We operate eight tailings dams in Russia and Kazakhstan; each is rigorously monitored daily. We are confident that any emergency dam failure would have no impact on local communities and employees.

“We welcome the new Global Industry Standard on Tailings Management and have committed to achieving compliance in all operations by 2023.”

In addition to state authority inspections of these facilities, the company conducted an independent third-party audit of its Mayskoye (Chukotka, Russia) tailings site, which was carried out virtually, due to COVID-19 restrictions, by Knight Piésold Ltd. “To further improve tailings safety and minimise the risk of the possibility of dam failure, we are shifting towards dry stack storage methods,” it said.

“Such facilities are already in operation at our Amursk and Voro (pictured filter press) mines, and will be extended to Omolon (2021), Nezhda (2021), POX-2 (2022), Dukat (2024) and Veduga (2025).”

Bluestone widens production plans with Cerro Blanco open-pit mining PEA

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Bluestone Resources has come out with a new open-pit mining plan for its Cerro Blanco project in south-eastern Guatemala that effectively doubles production and triples the potential investor returns from the gold-silver asset.

The preliminary economic assessment on Cerro Blanco, which comes just under 11 months after entering into an agreement with G Mining Services covering basic engineering and overall project optimisation efforts for the project, outlines a project able to produce 231,000 oz of gold at an all-in sustaining cost of $642/oz Au over the 11-year life of mine. This is based on a 15,000 t/d operation with a $548 million initial capital expenditure bill.

Using a base case gold price of $1,550/oz and silver price of $20/oz, an after-tax net present value (5% discount) of $907 million was calculated.

The numbers are significantly different from what the company outlined in a previous feasibility study on Cerro Blanco, completed by a consortium of independent consultants led by JDS Energy & Mining. This showed an average output of 113,000 oz/y of gold at an all-in sustaining cost of $579/oz and a capital cost of $196 million (including contingency).

Using a base case of $1,250/oz gold and $18/oz silver, this underground project was estimated to generate a post-tax net present value (5% discount) of $241 million.

Bluestone said on the PEA publication: “The recent completion of advanced engineering and optimisation work has significantly enhanced the understanding of the project and presented an opportunity to capitalise on its near-surface, high-grade mineralisation through an open-pit development scenario. This is a major change to Bluestone’s corporate strategy that will fully maximise the value of the Cerro Blanco gold project for all stakeholders.”

David Cass, Vice President of Exploration, added: “The pivot to surface mining is a culmination of our increased understanding of the geology and grade distribution that will realise the full potential of the Cerro Blanco low-sulphidation mineralisation. The inverted wedge shape of the deposit with its upper half forming the Cerro Blanco hill lends itself to surface mining with a low strip ratio.”

The project currently hosts 3 Moz of gold in the measured and indicated resource category and 250,000 oz of gold in the inferred mineral resource category.

The open-pit mining scenario envisages an owner-operated mining fleet using 65-t trucks matched with 7 cu.m hydraulic shovels supported by 8.2 cu.m wheel loaders. Mill feed will be trucked to a primary crusher located to the east of the main pit. Waste totalling 123.5 Mt will be placed in a waste storage facility.

In terms of processing, the PEA looks at treating 5.04 Mt/y of mineralised material at an average feed grade of 1.6 g/t Au and 7.26 g/t Ag through a conventional cyanide leach process plant to produce doré. The flowsheet is very similar to the previous underground mine option and includes primary crushing, single train SAG mill and ball mill to produce a target grind size of 80% passing 53 microns, atmospheric pre-oxidation, 48-hour cyanide leach, carbon-in-pulp carousel adsorption circuit, Zadra elution circuit, gold room and filtered tailings. Based on PEA metallurgical test work, the expected recoveries are 91% for gold and 85% for silver.

Filtered tailings will be configured in a dry-stack facility and eliminate the need for the construction and operation of a traditional tailings impoundment, the company says.

“The adoption of this technology (dry stacking) puts the Cerro Blanco project at the forefront of responsible mining practices being adopted for the future of sustainable mining globally,” it added.

Galena signs up Contract Power for hybrid power gen facility at Abra JV

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Abra Mining Pty Ltd, the joint venture company behind the Abra base metals project, has executed a power purchase agreement (PPA) with Contract Power Australia that could see the construction and operation of a hybrid power generation facility made up of a natural gas and solar energy array at the Western Australia project.

Announcing the PPA, Galena Mining, which owns 77.28% of the project, said Contract Power will build, own and operate an integrated hybrid power generation facility combining a 10 MW natural gas fired power station, a 6 MW solar array, 2 MW of battery energy storage and a 900 Kl LNG storage and regasification facility.

Power will be purchased by Abra under the PPA for an initial term of 16-years (extendable), it said.

Galena Managing Director, Alex Molyneux, said: “We’re pleased to partner with Contract Power on a clean, cost-effective power solution for Abra. Integrating solar with relatively clean natural gas instead of diesel achieves a marked reduction in Abra’s carbon footprint compared to alternatives considered in the tender process.

“Pleasingly, the design also offered the most cost-effective solution, in line with our feasibility study estimates.”

This definitive feasibility study outlined development of a mine and processing facility with a 16-year life producing a high-value, high-grade lead-silver concentrate containing around 95,000 t/y of lead and 805,000 oz/y of silver after ramp-up.

A Western Australia-based company wholly-owned by Pacific Energy Ltd, Contract Power specialises in the design, construction and operation of remote power stations for the mining and government sectors.

Contract Power has operated power stations around Australia under turnkey build-own-operate arrangements since 1999, and recent projects include a 56 MW gas fired power station for Mineral Resources Ltd’s Wodgina lithium project, a 18 MW gas fired station for Capricorn Resources’ Karlawinda project and a 18 MW gas and diesel power station at Wiluna Mining Corp‘s Wiluna gold project.

Contract Power’s Managing Director, Leon Hodges, said: “We are very pleased to be working with Galena on this important project and look forward to rewarding their confidence by delivering a world-class hybrid power station.

“Contract Power’s combined LNG and renewables integration capability has allowed our design team to maximise solar penetration as high as the economics and technology allows, providing the Abra project with the highest reliability and lowest cost of power on an unsubsidised basis.”

The PPA remains subject to the condition of Abra Mining Pty Ltd proceeding to final investment decision for the project, Galena said.

Peel Mining’s South Cobar preliminary flowsheet to factor in ore sorting

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Peel Mining says positive results from ore sorting test work at the Southern Nights and Mallee Bull deposits, part of its 100%-owned South Cobar Project, in western New South Wales, Australia, provide encouragement for the inclusion of this pre-concentration technology into future process plant design.

So encouraged by this testing is Peel that it has engaged GR Engineering to integrate ore sorting technology into an updated processing plant technical report for the project.

At the same time as this, Peel announced that GR Engineering had recently completed a preliminary process plant technical report for South Cobar that considers crushing, grinding, gravity, flotation and cyanidation process stages for the recovery of gold, silver, copper, lead and zinc from the various mineralisation styles within Peel’s deposits.

Meanwhile, the recently received positive preliminary ore sorting test work results from work undertaken on diamond drilling samples shows there is potential for improvements in the flowsheet.

The ore sorting test work, completed in conjunction with ongoing metallurgical studies, was undertaken by Steinert and TOMRA.

Steinert ’s test work on Southern Nights mineralisation demonstrated strong recovery and upgrade potential with two size range samples returning, on average, circa-93% Zn, circa-91% Pb, circa-91% Ag, circa-87% Cu and circa-82% Au recoveries to an average of circa-54% of the feed mass (circa-46% of feed mass rejection) increasing the lead and zinc grades by 61% and 64%, respectively.

TOMRA’s test work on Mallee Bull mineralisation achieved significant waste mass reductions while maintaining very high copper recoveries (≥95% for the higher-grade breccia copper and massive sulphide copper samples), the company said. A lower grade breccia copper sample upgraded from 0.59% Cu to 1.05% Cu with 77% Cu recovery and 56% mass rejection, it noted.

“Positive results from ore sorting at Southern Nights and Mallee Bull deposits provide encouragement for the inclusion of this pre-concentration technology into future process plant design and, as a result, Peel has engaged GR Engineering to integrate ore sorting technology into an updated processing plant technical report,” the company said.

Peel’s Executive Director of Mining, Jim Simpson, said: “The completion of the processing plant technical report by mineral processing solutions experts GR Engineering is a critical first step in understanding the potential composition of the milling infrastructure required for the company’s development plans.

“The detail presented in the report by GR is impressive and the report will form the basis for ongoing preliminary studies for the refinement and improvement of the processing plant design as new information comes to hand.

“We are also very pleased with the potential of ore sorting as part of any future South Cobar project hub’s processing route with initial test work pointing to the amenability of both Southern Nights and Mallee Bull mineralisation to separation using 3D-XRT ore-sorting technology, allowing for the simultaneous rejection of barren or waste material whilst retaining the bulk of contained metal, and in the process, upgrading the value of the ore.”

Simpson added: “Apart from reducing the overall feed mass by the rejection of waste at early stage, other benefits of ore sorting include potentially upgrading lower-grade mineralisation and reducing the size of the processing plant offering potentially reduced capital, power, water and tailings storage needs.”

Capstone prepares Cozamin for introduction of paste backfill, dry-stack tailings

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An updated Technical Report on Capstone Mining’s Cozamin copper-silver mine in Zacatecas, Mexico, has shown the potential for a mine life extension to 2031, and a plan for dry-stack tailings and underground paste backfill. At the same time, the company says it is studying the use of “innovative mining techniques and enhanced pillar recovery” to make the most of existing reserves and resources.

The updated life of mine plan released outlined average annual copper production of 51.2 MIb (23,224 t) of copper and 1.6 Moz of silver production over 10 years at average C1 costs, including the 50% silver stream, of $1.02/Ib of payable copper. From 2021 to 2027, average annual production is slated to be 58.8 MIb of copper and 1.7 Moz of silver.

The company said a planned ramp-up to 3,780 t/d, or 1.38 Mt/y, by the end of March quarter is on track, with a new section of ramp to open the one-way traffic circuit to debottleneck the mine (pictured) completed in early December 2020, ahead of schedule.

Reserves increased by 39% and now stand at 14.1 Mt, relative to April 30, 2020. Contained copper and silver increased by 37% and 49%, respectively, with around half of this increase due to recovery of high-grade pillars using paste backfill, Capstone said.

The miner said “tailings management transformation” activities were progressing on schedule at site, including feasibility-level design and studies in support of permitting a filtered (dry stack) tailings storage facility.

“This conversion from a slurry tailings impoundment aligns with industry leading socio-environmental best practice for tailings management,” the company said.

Meanwhile, a prefeasibility study (PFS) for an underground paste backfill system was completed in December.

The study indicates a paste backfill system will allow ore extraction containing over 100 MIb of copper and 3.1 Moz of silver between 2023 and 2031, which would have otherwise been left as unmined pillars. The PFS design has a capital cost estimate ranging from $41-$45 million and an increase in operating costs of around $7.50/t of ore mined. Capstone says its management has approved the paste backfill project and work has commenced on procurement of long lead items.

The proposed paste backfill system includes a tailings filter plant, a paste mixing plant, twin boreholes to deliver paste underground and an underground distribution system. The system is expected to be commissioned starting in the December quarter of 2022, with ramp-up completed in the March quarter of 2023.

PFS design of these facilities was completed by Paterson & Cooke in December 2020 and a feasibility study is underway with completion expected in April 2021. Mine planning was completed by Cozamin, with design support provided by a geotechnical consultant, and paste backfill operational guidance provided by AMC Consultants.

Within the latest release, Capstone also flagged the initiation of its “Impact23 Growth” project, which has identified areas of exploration excellence, innovative mining techniques and enhanced pillar recovery at Cozamin.

“By 2023, the goal is to further extend mine life, increase environmental and safety standards, and improve operational efficiencies at Cozamin, utilising mineral resources already discovered in addition to testing new targets,” the company explained.

Included among the options are the innovative mining techniques for resource to reserve conversion flagged at the start of this story.

Capstone says a study will be initiated this year to assess alternative mining techniques with the objective of lowering costs and dilution to convert resources to reserves from the indicated resource base. The current mining methods are longitudinal longhole open stoping and AVOCA, with possible alternatives to be studied including cut-and-fill, drift-and-fill and longhole open stoping with ore sorting technology.

Brad Mercer, Capstone’s SVP and Chief Operating Officer, said: “The life of mine plan announced today maximises extraction of the orebody’s high-grade core by deferring stoping in this area until the paste backfill plant is in operation in 2023. Projected production averages nearly 60 MIb of copper per year for seven years at first quartile costs.

“The Impact23 Growth project that we are kickstarting today is aiming to demonstrate in a 2023 technical report how Cozamin can sustain these levels of performance well into the 2030s.”

Darren Pylot, Capstone’s President and CEO, added: “After 14 years in operation, the best years of Cozamin are ahead. The mine is world class with sustainable low costs and leading safety and environmental performance entrenched throughout the organisation. The growth initiatives are supported by an entrepreneurial fabric at Capstone, as we embrace innovation and technology to create high impact value for our shareholders.”

Canada Silver Cobalt Works enlists SGS Canada for Re-2OX pilot plant build

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Canada Silver Cobalt Works has signed an agreement with SGS Canada Inc to proceed with its Re-2OX pilot plant in Ontario, Canada.

This critical step will allow the company to, it says, accelerate the production of client-specific battery metals for the North American electric vehicle (EV) market, one of its key strategies.

In 2018, SGS Lakefield used the environmentally friendly Re-2OX process to recover 99% of the cobalt and 81% of the nickel from a composite of gravity concentrates while also removing 99% of the arsenic, a long-time issue in this cobalt-rich Cobalt Camp. The gravity concentrates graded 9.25% Co, 5.65% Ni, 49.9% As and 9,250 g/t Ag.

The Re-2OX process, which skips the normal smelting process to create battery-grade cobalt sulphate, was used at SGS to produce a technical-grade cobalt sulphate hexahydrate at 22.6%, directly from cobalt-rich gravity concentrates produced from the first level of Canada Silver Cobalt Works’ Castle mine in the Cobalt Camp. The 22.6% cobalt sulphate compound exceeded the specifications required by battery manufacturers at that time, the company said.

The latest plan calls for SGS to design and build the Stage 1 pilot plant at Lakefield, Ontario. Feed material for this test work will come from the underground at the Castle mine, the high-grade silver discovery Robinson Zone, Beaver and Castle tailings, recycled batteries, and from newly acquired properties.

Management sees the Re-2OX pilot plant as a long-term strategic advantage that will facilitate the production of battery metals for the EV market for many years.

“More importantly, production can be certified as ethically sourced within stringent Canadian environmental standards and traceable verification of a closed-loop supply chain that will ensure this product is highly sought after and could even possibly garner a premium due to source verification,” the company said. “The cobalt ore will come from the Cobalt region including from the Castle property currently being aggressively drilled for high-grade silver and battery metals.”

The company has retained the services of ONSite Labs as an independent contract operator of the Temiskaming Testing Laboratories facility Canada Silver Cobalt Works acquired last year. ONSite is a commercial analytical lab operator.

Over the next four months, ONSite Labs will process samples to prove the ability to produce viable data with the highest standards of quality control, the company said, adding that the lab could be fully operational and open for business by the summer of 2021.

The Castle property is 15 km east of Pan American Silver’s Juby gold deposit, 30 km due south of Alamos Gold’s Young-Davidson mine, 75 km southwest of Kirkland Lake Gold’s Macassa Complex, and 100 km southeast of new gold discoveries in the Timmins West area.

Trevali Mining and Redpath plot Caribou zinc-lead mine restart plan

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Trevali Mining has enlisted the help of Redpath Mining to restart its Caribou zinc-lead mine near Bathurst, New Brunswick, Canada.

The mine has been on a care and maintenance program since March 2020 following a deterioration of the global zinc market and the continued challenges presented by COVID-19.

Armed with the implementation of several operational and commercial enhancements, as well as improved zinc market conditions, the company now expects to return to mining in early February, with first payable zinc production expected by the end of March.

Following ramp-up in 2021, the all-in sustaining cost (AISC) for Caribou is forecast to be between $0.84-$0.90/Ib of zinc in 2022. The AISC for 2021 is expected to be $0.91-$0.97/Ib.

This cost performance will be supported by a partnership with Redpath Mining as underground mining contractor at Caribou. Trevali says Redpath’s operational experience will help it safely and efficiently mine Caribou’s narrow mineralisation, with the company able to mobilise people and equipment quickly.

Also supporting the restart plan is the signing of a 21-month fixed pricing arrangement for a significant portion of the forecasted zinc production from the mine. Pursuant to existing offtake agreements, an affiliate of Glencore has agreed to purchase 115 Mib of payable zinc, which represents some 80% of the forecasted zinc production from Caribou, at an average price of $1.25/Ib.

These agreements are for the period from March 2021 to December 2022 and are in addition to Trevali’s existing hedging program, which covers the period from October 2020 to December 2021.

Trevali said it was also looking to enter into fixed-pricing arrangements for both lead and silver at meaningful levels of forecasted production from Caribou.

Production guidance for 2021 is estimated at between 60-65 Mib of payable zinc, 21-23 MIb of payable lead and 585,000-650,000 oz of payable silver. Zinc payable production is expected to increase to 72-77 MIb of payable zinc in 2022 as the mine receives the benefit of a full year of production.

During the initial 21-month operating period, Trevali says it will also continue to study metallurgical and operational opportunities to extend the current two-year mine plan, as well as other longer-term value enhancing initiatives in the Bathurst mining camp.

Ricus Grimbeek, Trevali’s President and CEO, said: “Our team has worked diligently to reduce the overall cost structure of the Caribou mine, and I am pleased that we are in a position to restart mine operations in a manner that we expect will generate positive cash flow.

“Our initial two-year plan includes several enhancements which are designed to improve the mine’s economics, including the involvement of a contracted mining operator and the entry into fixed-pricing arrangements for a significant portion of the mine’s forecasted production. We have benefited from the engagement of the provincial government, and with the recall of employees and the restart of production we look forward to being a more significant part of the New Brunswick economy.”

SNC-Lavalin to manage construction of Coeur’s Rochester silver-gold mine expansion

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SNC-Lavalin has been awarded a $30 million contract by Coeur Rochester Inc, a wholly-owned subsidiary of Coeur Mining, to provide construction management services for the Plan of Operations, Amendment Number 11 (POA 11) expansion project, at Coeur’s Rochester mine near Lovelock, Nevada, USA.

The contract commenced in the December quarter and is estimated to be completed by the end of 2022. This win is aligned with SNC-Lavalin’s new strategy moving forward in the Services segment, it said.

The POA 11 expansion project includes the construction of a new crushing plant, including a primary, secondary and tertiary crushing circuit (high pressure grinding rolls), a new heap leach pad (272 Mt), a new Merrill-Crowe process plant (62,509 litres/min), and upgrades to existing electrical utility system infrastructure, including a new substation and power distribution lines.

Coeur says this will more than double planned annual crusher throughput capacity from around 12.7 Mt to over 25.4 Mt, post-expansion. This will see average annual silver and gold production total over 8 Moz and some 80,000 oz, respectively, for the initial 10 years, post-expansion

SNC-Lavalin said: “This mandate is well aligned with our expertise in silver, gold and base metal project delivery as well as our commitment to delivering real value to our clients.”

SNC-Lavalin’s offices in Reno, Nevada, and Toronto, Ontario, will continue to support the construction management phase of the project. In addition, a team based locally at the site will manage construction-related activities.

César Inostroza, Senior Vice-President, Mining & Metallurgy, SNC-Lavalin, said: “SNC-Lavalin’s Mining & Metallurgy strategic plan is gaining traction with this mandate. It is an example of the mining services work that our team is winning across our core geographies, including the USA. SNC-Lavalin and Coeur continue to foster a strong relationship that finds and executes services solutions to create world-class operations

“This award is a testament to the continued partnership between SNC-Lavalin and Coeur. It leverages our knowledge of the Rochester mine and engineering expertise from the previous phase of this project and expands our work in the US.”

Terrence FD Smith, Coeur’s Senior Vice President and Chief Development Officer, added: “The strong business partnership between Coeur and SNC-Lavalin will help ensure a robust project delivery for Rochester, paving the way for improved performance in the future.”

Since approval of the initial Plan of Operation in 1986, the Rochester mine has undergone periodic mine plan amendments to support development projects and continued operations. The POA 11 proposes another mine life extension, which is expected to maintain the current workforce and support full production activities at Rochester until 2033.