Tag Archives: zinc

Trevali to test out FLSmidth’s Rapid Oxidative Leach tech on Caribou material

Trevali Mining has announced the commencement of a pilot plant testing program using Caribou run-of-mine and milled material at FLSmidth’s Rapid Oxidative Leach (ROL) process testing facility in Salt Lake City, Utah.

The program expands on previous laboratory test work and is aimed at demonstrating the potential to recover zinc, lead, copper, gold and silver as a precipitate or metal and additional zinc and lead from Caribou ore and mill tailings.

The leach test program is targeting an improvement to zinc, lead, copper, gold and silver metal recoveries, the potential to produce a precipitate or metal on site replacing the current ore concentrate that is produced at Caribou – which, if implemented, would lead to savings on transport costs and offsite treatment costs – and the opportunity to process historic mill tailings, which include gold and copper metals, in addition to run of mine ore. The latter would increase revenues and reduce closure liabilities, Trevali said.

Trevali says the use of FLSmidth’s ROL technology also provides the potential to reduce Trevali’s carbon footprint at Caribou and extend Caribou’s mine life and treat lower-grade deposits in the Bathurst camp of Canada.

FLSmidth says ROL leaches 97-99% of copper directly on-site in six to eight hours, from concentrates as low as 5% Cu. In gold, ROL has the potential to unlock the value of undeveloped refractory gold deposits with less than 3 g/t gold head grade, it says.

Unlike other refractory processing techniques, the ROL process uses the application of mechanical energy coupled with oxidation under atmospheric conditions. The process relies on stirred media reactors to accelerate the oxidation of sulphide minerals. This eliminates the need for ultrafine grinding, high temperatures and high pressure which makes it energy saving and very cost-effective, according to the mining OEM.

Trevali said a successful pilot plant test program using ROL may allow Trevali to replace the existing flotation circuit at Caribou with atmospheric leach vessels and potentially an SX/EW train, introducing the possibility of producing base and precious metals on-site and thereby save transport costs and offsite treatment costs.

Conceptual objectives of the program include:

  • Recovery of metals/minerals that are not recoverable using the current technology at Caribou (precious metals and magnetite); and
  • Improved payables/selectivity of the traditional flotation process using new and emerging technologies.

Ricus Grimbeek, President and Chief Executive Officer of Trevali, said: “FLSmidth’s ROL metallurgical technology has the potential to transform the Caribou mine and the wider Bathurst Mining Camp.

“This next phase of the testing program is an essential step in evaluating the suitability and economic viability of a processing solution with the potential to enhance the value of the in-situ material and tailings at Caribou as well as the surrounding deposits in the Bathurst region. The positive results to date support further study and analysis given the potential implications for the Bathurst Mining Camp in general and Trevali in particular.”

Beyond quantifying the ability to recover additional metal values, the objective for the pilot plant test program is to determine the various kinetic factors, mass and energy balance and engineering data to support future engineering on a preliminary economic assessment for potential processing of the Trevali mill feed and mill tailings and produce metal on site.

Continuous pilot plant trials commenced in June 2021 (Phase 1) to tune the pilot plant and provide material for precious metal leach tests in late July, followed by a test program at the Caribou Mine site that is planned for September 2021 (Phase 2). Leach data and results are expected to verify that batch testing results can be achieved in a continuous operation.

ANDRITZ ups the filtration ante with new ME2500 filter press

ANDRITZ has introduced a new filter press, the ME2500, to complete its range of “proven” A4F and the SE series filter presses for the mining and minerals industry.

The ME2500 is the best-fit for fast processing of tailings (also with high clay content) or mining concentrates like iron, copper, lead or zinc, the company says. The new model has an hourly processing capacity of up to 450 kg/sq.m, a filtration area of up to 840 sq.m, and features chained plates for faster filter cake discharge. These attributes enable the highest throughputs without compromising on safety, while reflecting a customer focus on saving water, ANDRITZ says.

The innovative closure system on the ME2500 largely replaces hydraulic components with electrical ones and further reduces cycle times, thus increasing capacity and operating availability.

“The increased use of electrical components enables highly sustainable operation of the filter press by reducing the amount of hydraulic oil needed, as well as improving safety thanks to more precise control and less reliance on high-pressure lines that are susceptible to leaks,” the company said.

In addition, and to further optimise the productivity of single machines or plants with multiple filter presses, all modules of the ANDRITZ intelligent filter press – controlled by the Metris addIQ control system – are also available for the ME2500 filter press and can be provided with the full range of options. This draws on smart sensors, data analytics and augmented reality, including multiple sensors to allow for online safety monitoring of the plate package and moveable parts.

The company concluded: “The safe disposal of tailings generated by the mining and minerals sector is a significant cost factor for the industry. ANDRITZ is known for its innovative range of overhead and sidebar filter presses that meet the industry’s most stringent requirements with regard to fast cake discharge and saving water and costs. The maintenance-friendly equipment from ANDRITZ is easily upgradeable, with a modular design for customised process solutions.”

BAUER builds foundations with Teck at Red Dog mine in Alaska

BAUER Foundation Corp and its jet grouting and Cutter Soil Mixing (CSM) methods are being put to the test in arctic conditions at Teck Resources’ Red Dog zinc mine in Alaska as part of a project to improve ground conditions at the operation.

Red Dog is one of the world’s largest zinc mines, located in the northwest of Alaska, around 170 km north of the Arctic Circle and nearly 1,000 km to the northwest of Anchorage. The mine has been operating since the late 1980s with around 10% of the world’s zinc extracted here by open-pit mining.

Its location in the Arctic Circle means the entire mine is in a geological permafrost area that keeps the ground permanently and completely frozen below a certain depth. There is, however, an active zone near the surface that thaws during the summer and refreezes during winter.

Based on an evaluation of the permafrost and soil on the site, ground improvements were identified as a prudent measure to counteract the effects of potential melting permafrost, BAUER said. To this end, BAUER Foundation was tasked by Teck with carrying out field tests using the jet grouting and CSM methods.

“The trials included detailed data capture and strict quality controls in close collaboration with Teck, the project owner, and other geotechnical consulting engineers,” Alejandro de la Rosa Knecht, Project Manager with Bauer Foundation, explained. “Trials were carried out from August to December of 2019, which ultimately identified the CSM method as the most suitable choice for the main scope of this project.”

The CSM method combines features of the diaphragm wall technique and the mixed-in-place ground improvement method (MIP). The soil is broken up using a cutter, then rearranged and mixed with an aggregate.

The trials for Red Dog also determined the extent to which existing subsoil were to be replaced with suitable filler material to facilitate later mixing.

In 2020, during the period from July to November, 50% of the pre-drilling was completed as well as 30% of the CSM. In addition, BAUER Foundation was tasked with the construction of a secant pile wall as an extension to an existing slurry wall. To achieve this, the required pile wall was integrated into the existing slurry wall and the underlying rock using primary and secondary piles. In all, 93 secant piles were constructed. A multi-purpose BAUER BG 30 drilling rig with special Arctic equipment along with various drilling tool and mixer sets were used for the execution of all the works.

One of the main challenges was the mobilisation of equipment in the limited time provided by the schedule, BAUER said. However, the required special equipment was mobilised in record time. Some equipment was transported by plane and then by ship from Seattle Harbour across the Bering Sea to a dock just over 80 km from the mine. Other equipment was transported via Hercules aircraft from Anchorage airport to the airport on the mine site. This logistical success was made possible by close collaboration with various BAUER subsidiaries and Teck, BAUER said.

“The remote and isolated location, the long deployment times and accommodation in camps pose additional challenges, as do the extreme Arctic climate conditions, precautionary measures associated with the corona pandemic and the specific safety requirements of the mining industry,” de la Rosa Knecht said.

Despite all these challenges, the Bauer and client teams were able to successfully conclude trial work between August and December 2019 and the first phase of production activities between July and November 2020.

The final production phase, which includes CSM and demobilisation, is due to be completed by June 2021.

Antamina leveraging MineSense’s in-shovel ore sorting technology

The largest mine in Peru, Antamina, has started using MineSense’s ore sorting technology as it looks to increase ore loading accuracy at the joint venture operation.

MineSense’s ShovelSense technology provides significant value to mine operators by identifying ore and waste, and classifying ore at the earliest stage possible in the mining process, the extraction face, using X-ray Fluorescence sensors, the Vancouver-based company says.

It has proved this technology out at multiple mine sites in North America, including Teck Resources’ Highland Valley Copper operations and Copper Mountain Mining Corp’s namesake mine, both of which are in British Columbia, Canada.

Enrique Parades Rivero, Mine Manager at Antamina Mine, stated at the recent Comasurmin 2021 conference that Antamina “plans to know what ore grades the mine is processing to the millimetre,” and this ore characterisation data is provided by MineSense’s ShovelSense technology. This technology, MineSense says, enables mines to generate more metal to increase profitability and improve operations, while optimising sustainability performance.

In terms of loading equipment, Antamina reportedly operates seven P&H 4100XPC electric shovels, four Hitachi EX5600-6 hydraulic shovels and two Cat 994F wheel loaders. Some of this loading equipment is interacting with the first fleet of electric drive 372 t class 798 AC Cat trucks in the country, which Ferreyros, the Caterpillar dealer in Peru, recently successfully put into operation.

The Antamina copper/zinc mine is owned 33.75% by BHP, 33.75% by Glencore 33.75%, 22.5% by Teck and 10% by Mitsubishi.

Telson Mining ready to experiment with metallurgical innovations at Campo Morado

Telson Mining, following a strong quarter of production from the Campo Morado mine, in Guerrero State, Mexico, is making plans to boost throughput and recoveries through the potential use of grinding, leaching and flotation technologies from the likes of Maelgwyn Mineral Services, Core Group and Glencore Technology.

The mine’s throughput averaged out at 58,100 t/mth in the March quarter, with total throughput for the quarter of 174,400 t being 4% higher than the December quarter. Some 11,013 t of zinc concentrate and 1,907 t of lead concentrate was produced over the period, compared with 9,974 t and 1,916 t, respectively, in the previous quarter.

Gold, silver, lead and zinc recoveries all improved, quarter-on-quarter, in the first three months of the year, the company added.

Ralph Shearing, Telson CEO and President, said: “These strong first quarter results continue to reflect our steady progression of improving the throughput and recoveries at Campo Morado. To this end, management intends to initiate a rigorous metallurgical testing program to advance through second phase testing the Leachox™ Process of Maelgwyn Mineral Services and the Albion Process™ of Core Group, both of which returned positive test results in first phase testing.”

He said this metallurgical testing program will also study the ability to increase base metal recoveries at microfine grinding with flotation recovery using Imhoflot Flotation (also Maelgwyn) and Jameson Cell (Glencore Technology) flotation technologies, both designed for such purposes.

“We are confident that additional recovery improvements are available utilising these exciting modern technologies which, if successful, can provide increased revenue streams,” Shearing added.

Maelgwyn’s Leachox Process consists of several Maelgwyn proprietary processes linked together including Imhoflot G-Cell flotation technology, ultra-fine grinding using the Ro-Star mill, Aachen Reactors and Aachen assisted cyanide destruction.

The Albion Process, meanwhile, is a combination of ultrafine grinding and oxidative leaching at atmospheric pressure. The feed to the Albion Process is refractory base or precious metal concentrates, where the sulphides in the feed are oxidised and liberated, allowing the target metals to be recovered by conventional means.

Foran Mining assembles FS team for ‘world first’ carbon neutral copper mine project

Foran Mining says it has bolstered the design team for its ongoing definitive feasibility study at the McIlvenna Bay project, in Saskatchewan, Canada, providing the company with the technical expertise to execute on its strategy of building the world’s first copper mine designed to be “carbon neutral” from day one of production.

The advisors are anticipated to employ a range of technologies and initiatives in the design of the mine and processing facilities to materially reduce greenhouse gas emissions and the environmental impact of the operations.

Foran says its due diligence to date has highlighted the potentially superior returns achievable through implementing this strategy, while the use of battery-electric vehicles will also be safer for employees, reducing risk of injury and physical stressors, such as vibration and noise.

The FS team includes experts from:

  • Stantec – mine design and engineering;
  • Knight Piésold Ltd – tailings storage facility design;
  • Halyard Inc – process plant design;
  • Micon International Limited – resource estimate;
  • Base Metallurgical Laboratories Ltd – metallurgical testing;
  • Canada North Environmental Services Ltd – environmental; and
  • Synergy Enterprises – sustainability and carbon accounting

Dan Myerson, Executive Chair of Foran, said: “The appointment of these world-class environmental and engineering specialists reflects our ambition to develop a technically and economically compelling solution to the environmental and social challenges which have been traditionally associated with the sector. We are therefore thrilled that professionals of this calibre have agreed to support us on this journey.”

He added: “Together, we intend to ensure that our operations emit net zero greenhouse gases and set new safety benchmarks for the industry, while also ensuring that the local community and the broader Canadian population benefit from our operations. The responsible production of copper and zinc is critical as the world transitions to a low carbon future; these metals are used in the production of renewable energy assets and electronic industries, for example. We look forward to providing more updates, in relation to our infill and expansion drilling, as well as announcing more detailed plans about how we will be putting our ambitions into practice.”

The 2020 prefeasibility study on McIlvenna Bay envisaged a 3,600 t/d underground operation with on‐site crushing and mineral processing facilities, a paste plant and filtered tailings storage facility. It considered a nine-year life of mine and scheduled treatment of the full reserve of 11.34 Mt grading 4.01% Zn, 1.14% Cu, 0.54 g/t Au and 20.97 g/t Ag. It also included plans for McIlvenna Bay to be an early adopter of battery-electric haul trucks.

Foran recently commenced its largest drill program ever (pictured), with over 30,000 m of infill and expansion drilling in the deposit. This has been designed to maximise the conversion of the current inferred resource to the indicated resource category, which can then be interrogated for inclusion in the updated reserve statement.

Foran says the feasibility study will, among other things, look to:

  • Further optimise and detail the McIlvenna Bay project engineering, including the estimation of reserves, mine design, stope sequence, development and production schedules;
  • Refine power and equipment requirements to support the company’s commitment to carbon neutral operations;
  • Update and detail the design and feasibility of the tailings desulphurisation process, dry stack storage facility and cemented paste backfill processes;
  • Provide detailed construction scheduling, including optimisations that would arise from pre-fabrication and/or modular (off-site) construction to the greatest extent possible;
  • Identify further mine optimisation to increase productivity and reduce operational expenditures; and
  • Consider equipment usage and activities where greenhouse gas emissions can be eliminated, reduced or offset to ensure that McIlvenna Bay is a carbon neutral operation.

BQE Water achieves several firsts with Zhongkuang SART plant operation

BQE Water says it has advanced the SART plant it designed for a gold metallurgical facility owned by Shandong Zhongkuang Group Co Ltd, in China, to full production.

Located in the Shandong Province in eastern China, the plant is now being operated under the ongoing technical supervision of BQE Water.

Implementing SART (sulphidisation, acidification, recycling and thickening) at the site improves both the environmental performance and project economics of the metallurgical facility, BQE said. Specifically, the SART plant eliminates the need for cyanide destruction, recovers copper and zinc as separate sulphide concentrates, and recycles free cyanide recovered by the plant to gold leaching.

BQE was awarded the SART plant contract back in 2019 following the positive outcome of an engineering feasibility study and on-site testing completed by BQE Water earlier in the year.

The Zhongkuang SART plant also represents many firsts, according to BQE:

  • It is the first application of SART globally where the cyanide competing base metals, copper and zinc, are recovered simultaneously from the leach solution as two separate high-grade concentrates that can be sold to generate incremental revenues;
  • It is the first commercial scale application of SART in China;
  • It is the first SART plant where lime is used to control gas emissions to reduce operating costs and control the build-up of salts in the process water; and
  • It is the first SART plant to be integrated into a complex metallurgical flowsheet that combines mineral flotation with cyanidation and SART in a Zero Liquid Discharge metallurgical facility with complete water recycle.

Songlin Ye, Vice President for Asia at BQE Water, said: “We are very proud of our China-based operations team for this significant achievement and that they were able to do so considering the challenges associated with the COVID-19 pandemic. The Zhongkuang SART plant is our flagship project for the China gold sector and other gold producers in the country are taking notice.”

David Kratochvil, President & CEO of BQE Water, added: “The many firsts associated with the Zhongkuang SART plant demonstrates our leadership in SART technology. And through the unique combination of engineering know-how and operations expertise, the project also shows our ability to reduce risks and achieve predictable outcomes for our clients.”

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

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.”

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

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.”

Canada Nickel investigates Crawford processing potential at Glencore’s Kidd concentrator

Canada Nickel Co says it has entered into a non-binding Memorandum of Understanding (MoU) with Glencore Canada that could see material mined from Canada Nickel’s Crawford nickel-cobalt sulphide project treated and processed at Glencore’s Kidd concentrator and metallurgical site in Timmins, Ontario.

Crawford, around 40 km north of Glencore’s operations, hosts a 657 Mt measured and indicated resource grading 0.26% Ni and 0.013% Co. It is currently the subject of a preliminary economic assessment (PEA).

The Kidd operations consisting of the Kidd metallurgical site and the Kidd mine. The concentrator is located on the property of the Kidd Metallurgical Site, 27 km east of Timmins, in the Townships of Hoyle and Matheson. Built in 1966 with numerous upgrades over the years, the concentrator currently processes metal ore to produce copper and zinc concentrates. The facility has a design rated capacity of 12,500 t/d and is fully permitted with water taking and discharge permits and thickened tailings storage. The site has incoming and outgoing rail service via Ontario Northland Railway.

Canada Nickel says it has completed an initial high-level assessment of the potential arrangements envisaged under the MoU and will proceed with a detailed study on the potential for upgrading excess capacity at the Kidd concentrator and/or using the existing infrastructure in place at the Kidd metallurgical site for milling and further processing the nickel-cobalt and magnetite concentrates that are expected to be produced from Crawford.

Mark Selby, Chair and CEO of Canada Nickel, said: “The opportunity to utilise the excess capacity and existing infrastructure at the Kidd Met Site provides the potential to allow a faster, simpler, smaller scale start-up of Crawford at a vastly lower capital cost while the company continues to permit and develop the much larger-scale project currently being contemplated.

“Given the potential for this significant change in the scope of the project start-up, the release of the PEA will be delayed until the end of March 2021 to allow this option, if successful, to be incorporated.”

This study is being led by Ausenco Engineering Canada Inc, which is also supporting the assessment of the Kidd Met Site facilities.

Canada Nickel’s plans include the development of a “Zero-Carbon footprint operation”. This considers the use of electric rope shovels and trolley trucks which utilise electricity, rather than diesel fuel, as a power source wherever possible, along with a natural mineral carbonation approach for the deposition of waste rock and tailings during mining to allow material to absorb CO2.