Tag Archives: Eldorado Gold

Dingo predictive maintenance solution cuts equipment downtime at Eldorado Lamaque

Dingo Software is helping Eldorado Gold’s Lamaque mine in Quebec, Canada, optimise maintenance and reliability practices through leveraging the company’s predictive and condition-based maintenance solutions.

The Lamaque mine faced the dual challenge of controlling capital costs and lowering all-in sustaining costs while also navigating the complexities of the global supply chain. With a current life of mine of 10 years, the mine sought to address some of these persistent challenges.

Lamaque decided to first focus on limited access to personnel with reliability skillsets, underutilisation of some of the existing digital platforms and its exposure to the global parts shortage. The team sought solutions to help control and reduce costs, extend the lifespan of major asset components and build world-class reliability expertise, Dingo says.

The site team, in collaboration with Dingo, identified opportunities to enhance equipment maintenance and reliability key performance indicators (KPIs). The chosen strategy aimed to reduce unplanned breakdowns, extend component life cycles, increase equipment availability and mitigate the impact of the global parts shortage.

Martin Pichette, Mine Operations and Maintenance Director at Lamaque Mine, said: “Partnering with Dingo allows us to leverage remotely-located condition intelligence experts from the get-go for a fraction of the normal cost to the company. This allows our few reliability experts to focus on the top issues and make important decisions to ensure our fleet availability is where it needs to be instead of having them analysing data and looking for the issues.”

Dingo also helped Lamaque acquire new sources of business intelligence with a fully documented and centralised asset health database plus integration with the ERP/CMMS, ensuring a complete maintenance and reliability context is available to support all maintenance decisions, it said.

Phase 1 of the Dingo solution involved consolidating oil sample data into a single platform for the first time at the mine. Within a short timeframe after the go-live, critical issues were identified and shared with the site team.

In the first week after go-live, the Dingo Condition Intelligence team observed a 2% fuel dilution, decreased viscosity, increased wear metal values and combustion by-products on a Caterpillar AD30 underground truck with a C15 engine with only 1,391 operating hours.

In response, the Dingo team assigned a ‘Priority 1’ action, providing work-stop level recommendations and provided site with a troubleshooting guide from their library, including recommendations to check the fuel injectors.

Not long after, the local OEM (Toromont) supporting Lamaque identified five defective fuel injectors that required urgent replacement. However, due to the ongoing global parts shortage, the mine was left with no alternative but to perform an engine oil drain on a weekly basis until the necessary parts could be procured. Once available, the injectors were replaced under warranty. This preemptive action not only prevented potential engine failure on the Cat AD30 but also restored up to 90% of the engine’s at-risk lifespan, according to Dingo.

While this proactive intervention circumvented much larger production losses had the engine been lost, it also highlights the significant risk unplanned breakdowns can have on Mean Time in Repair and associated production losses.

Dingo said: “The joint effort between the Lamaque personnel, CAT Toromont and Dingo Condition Intelligence specialists not only averted a catastrophic breakdown but also showcased the effectiveness and rapid results achievable through Dingo’s predictive maintenance solutions. The successful identification and repair of the AD30 injectors resulted in significant cost savings for everyone. In a nutshell, such a breakdown, if it had not been prevented by the team, would have generated production losses of about $65,000 per day due to equipment downtime and significant corrective maintenance cost to the OEM under warranty.

“Beyond financial value capture, this case also aligns with Eldorado Gold’s vision of ‘breaking new ground’ by implementing innovative solutions and enhancing maintenance processes, thereby ensuring the continuous growth of their high-quality business.”

After the AD30 engine save, the Lamaque maintenance team have continued to leverage Dingo to save equipment. For example: three leaking fuel injectors were found on a 45 t haul truck and a transmission was saved on a 15 t LHD; two key prime movers that would have impeded the operation from monthly production targets. Overall, working together, Dingo and Lamaque have now secured three significant equipment ‘saves’ within the first four-month period, Dingo says.

Building on these early successes, Lamaque and Dingo plan to continue to extend the project to the entire fleet, according to Dingo. Next steps will include interfacing with the mine CMMS and leveraging Dingo’s global benchmark tool to help select best practices from similar mines worldwide and to help the mine evolve towards increasingly condition-based maintenance decision making.

Dingo concluded: “This success story exemplifies how proactive maintenance strategies, coupled with innovative partnerships, can not only address immediate challenges but also pave the way for a more efficient future in the mining industry.”

Resourcing Tomorrow

Major miners join Resourcing Tomorrow lineup

Representatives from the world’s largest mining companies Anglo American, BHP, Glencore, Rio Tinto and Vale have confirmed their attendance for this year’s Resourcing Tomorrow event, in London, event organisers say.

These attendees will join other leading mining companies including AngloGold Ashanti, Antofagasta Minerals, Barrick, B2 Gold, Eldorado Gold, Endeavour Mining, Freeport-McMoRan, Newmont, Sibanye-Stillwater and Teck Resources.

As Europe’s largest mining event, Resourcing Tomorrow: Accelerating the Energy Transition takes place in London on November 28-30 and is poised to be yet another agenda-setting edition for the industry, fostering collaboration and knowledge exchange among professionals in the field, event organisers say.

Resourcing Tomorrow unites all stakeholders in the mining industry, including global mining and energy companies, investors, government delegations, researchers, educators, regulators, suppliers and operators. The conference program will provide 100-plus sessions in which all of the aforementioned miners will participate, giving attendees the opportunity to engage and network with leaders and industry specialists from around the world.

The event will draw participants from more than 100 countries, including Australia, USA, UK, Canada, India, Brazil, South Africa, Ghana, Chile, Nigeria, Peru and Germany, demonstrating its international appeal and the global significance of the mining industry, organisers say.

With the increasing pace of change and emerging technologies in the mining industry, Resourcing Tomorrow will focus on the future of our industry and presents a unique opportunity for international representatives of the world’s leading resource economies to meet, find new partners, discuss current challenges, and share the latest research, technology and best practice.

International Mining is a media sponsor of Resourcing Tomorrow.

Eldorado’s Lamaque mine receives first Sandvik TH550B battery-electric truck

Eldorado Gold Quebec, which operates the Lamaque underground mine in Val-d’Or, says it has become the first mining company in Quebec to integrate a Sandvik TH550B battery-electric truck into its fleet.

This truck, with a maximum capacity of 50 t, will play a key role in improving production efficiency, protecting the health and safety of workers, but above all in mitigating our gas emissions, the mining company said.

Back in March, IM reported that Eldorado was expecting to receive its first battery-electric truck in June for use at Lamaque, with the operator confirming a second truck was scheduled to arrive by the end of the year.

The introduction of these electric trucks is part of the strategy of progressive electrification of the equipment fleet at Lamaque, and also supports efforts to electrify transportation in the Sigma-Lamaque underground ramp, the company said. As the first mining company in Canada to adopt this technology, Eldorado Gold Québec has worked closely with Sandvik to develop these trucks.

Sylvain Lehoux, Vice-President, Canada, said: “We are pleased to be able to begin the electrification of our underground operations thanks to the arrival of this electric truck, which will bring us several benefits, particularly in terms of mitigating our GHG emissions, but also for improving certain aspects of the health and safety of our employees. Over the next few weeks, our employees will be trained and this equipment will be in the testing phase in our operations. We are all looking forward to seeing this technology in action and actively pursuing our efforts to decarbonise our operations.”

Although the Lamaque mine is already recognised as one of the lowest GHG-emitting gold mines in the world, thanks in large part to access to hydroelectricity and the implementation of energy efficiency projects, it is expected that the use of these electric trucks will, once fully functional, reduce GHG emissions estimated at 1,700 tCO2 per year, the company says. This reduction is explained by the absence of diesel consumption and the 100% use of renewable electricity supplied by Hydro-Québec.

Eldorado testing LTE-backed Newtrax ventilation on demand solution at Olympias

Eldorado Gold has confirmed it is testing Newtrax’s environmental monitoring platform and ventilation on demand (VoD) solution at the Olympias mine in Greece.

Mine ventilation represents the single largest electrical load at the Olympias mine and, in response to the EU energy crisis and Eldorado’s own Energy and Carbon Management System, the company has been aggressively advancing VoD implementation at the Greek operation.

The benefits associated with VoD include:

  • Targeted air circulation and improved air quality as the working environment is upgraded as fresh air is distributed through the mine in a manner that ensures workers’ health and safety;
  • Right-sizing fans to provide the required volumetric flow rates (from a static to a dynamic and intelligent air supply leading to a reduction of the total required airflow within a mine);
  • Improving energy efficiency and power consumption – by reducing the total airflow, energy can be saved in disproportionately high amounts due to the cubic relationship between volume flow and fan power; and
  • Enabling the production and development activities at the lower levels of the mine.

To obtain the immediate benefits of VoD, the Olympias mine operations team implemented a manual solution during 2022, where the team adjusts ventilation fan operations each day based on the daily mine plan. As part of this, variable speed drives were applied to many of the fans to allow air flow adjustments to meet operational needs with minimum electricity consumption. This process is being carried out via the control room on surface, with a SCADA system used to disconnect fans that are not planned to be used during the day.

This transition saw ventilation fan consumption decrease from about 620 kWh/mth of electricity consumption per kW of installed fan capacity to about 377 kWh/mth of electricity consumption per kW of fan capacity, representing a 40% decrease in energy consumption, according to Simon Hille, SVP, Technical Services and Operations. At the end of 2022, the mine had 3.1 MW of installed ventilation capacity.

“This 40% reduction represents about 9,051 MWh/y of electricity savings and about 3,800 t/y of GHG emission reductions (utilising the updated emissions factor of 0.42 t CO2e/MWh),” he told IM.

While manual VoD has been very effective, automated VoD will further decrease energy consumption and eliminate the many worker hours required to implement VoD on a daily basis, according to Hille.

This is where the company brought in Newtrax, part of Sandvik Mining and Rock Solutions, to implement an automated VoD system.

The Olympias mine will be the first Newtrax installation utilising LTE as the communications medium versus low frequency radio (leaky feeder) utilised previously, according to Eldorado. LTE was installed in August 2022 with the help of Cosmote.

The automated platform will also leverage data from the existing Micromine fleet management system and RFID-based employee location tags provided by Newtrax. Ventilation will then be provided by surface fans with higher ventilation capacities.

Olympias already uses Accutron Technology to monitor air flow velocity and Trolex technology to monitor mine air quality, according to Hille.

In addition to the VoD benefits, the Newtrax technology will improve mine safety (mine evacuation and rescue) as well as improve productivity by allowing mine supervision to have a better understanding of resource locations for improved decision making, the company says.

“Technology and connectivity are the key parameters for VoD to operate effectively,” Hille said. “Automated employee and equipment geo-location is necessary as it helps adjust ventilation delivery to different areas by effectively shutting down entire areas and thus reducing the overall ventilation demands. This requires smooth connectivity with the LTE across the mine site.”

Last month, Newtrax installed five Bluetooth low energy (BLE) devices on select mobile machinery to test system connectivity. Once troubleshooting is complete and communication is established between the underground fans and Newtrax BLE devices, full-sized implementation will be considered with equipment procurement, installation and commissioning to be done by end of Q1 (March quarter) 2024.

On top of this, Eldorado Gold is evaluating non-diesel powered equipment for all new equipment purchases and, in some cases, as an alternative to equipment rebuilds.

“The mine ventilation benefits of equipment electrification are included in the evaluation of that equipment,” Hille said.

Eldorado Gold to electrify haulage at Lamaque with Sandvik TH550B BEVs

Eldorado Gold is looking to take its next mobile equipment electrification step, with the company set to receive its first battery-electric truck in June for use at the Lamaque underground mine in Quebec, Canada.

The Vancouver-headquartered company has already trialled a battery-electric Normet SmartDrive concrete transportation vehicle at its Efemçukuru gold mine, in Türkiye, as part of a wider group remit to mitigate greenhouse gas emissions (GHG) by 30%, from 2020 levels, by 2030 on a ‘business as usual’ basis; equal to approximately 65,000 t of carbon dioxide equivalent.

Now the company is moving from this electric utility vehicle trial to acquiring two battery-electric trucks for use at its flagship Canadian mine.

In its recent 2023 guidance, Eldorado said it expected to spend $37-42 million on growth capital at Lamaque this year, including non-sustaining exploration expenditures for resource conversion and resource expansion drilling at the Ormaque and Parallel deposits, tailings management and electric underground trucks.

A spokesperson for the company confirmed the electric underground truck investment relates to the acquisition of two Sandvik TH550B battery-electric trucks.

These 50-t payload battery-powered trucks combine Sandvik’s 50 years of experience in developing loaders and trucks with Artisan™’s innovative electric drivelines and battery packs. The electric drivetrain delivers 560 kW of power and 6,000 Nm of total torque output, allowing for higher ramp speeds for shorter cycle times and an efficient ore moving process, according to the OEM. All of this comes with zero emissions.

These vehicles also come with fast and easy battery AutoSwap and AutoConnect functions that Sandvik has refined for battery swap processes that take only a few minutes.

The Eldorado spokesperson said: “We have purchased two units; the delivery for the first unit is in June and the second one in November 2023. The Lamaque Mine continues to perform as one of the lowest GHG-emitting gold mines in the world because of access to low-emission hydroelectricity in Québec and other site-based energy efficiency projects. Electrification of these underground vehicles has the benefit of reducing diesel usage on our site and, in addition, we can also be certain that we’re not passing on our direct Scope 1 emissions to Scope 2.”

The company’s sustainable focus at Lamaque goes beyond the acquisition of these two Sandvik vehicles.

Lamaque is expected to produce some 170,000-180,000 oz of gold at C1 cash operating costs of $670-$770/oz sold in 2023, the company says

Eldorado has recently eliminated 26 km of surface haulage and rehandling on public roads at Lamaque, reducing GHG emissions. It has also increased the operation’s energy efficiency, cut its ambient noise and reduced surface dust.

Lamaque is expected to produce some 170,000-180,000 oz of gold at C1 cash operating costs of $670-$770/oz sold in 2023, the company says.

Eldorado turns to Metso Outotec for dry stack tailings solution at Skouries

Metso Outotec says it will deliver sustainable filtration technology for dry stacking of tailings to Eldorado Gold’s Hellas Gold Skouries copper-gold concentrator project in northern Greece.

Metso Outotec’s scope of delivery consists of the engineering, manufacturing and supply of several Planet Positive Larox® FFP3512 filters as well as installation and commissioning advisory services. The fully automatic, fast-opening filter press (FFP) combines the benefits of membrane technology and sidebar design with high mechanical and process performance, providing safe and sustainable high-volume dewatering of tailings at low operating and life cycle costs, according to the company.

Brock Gill, SVP Projects & Transformation for Eldorado Gold, said: “Skouries is a world-class project, and we are aiming for best-in-class sustainable technologies in the project design. For tailings management, the Skouries project will use dry stack tailings impoundment, which requires less space, reduces water consumption and maximises recovery of process water for reuse. Metso Outotec filters were selected as key and proven technology for the dry tailings facility not only because of their performance, but also because of their energy efficiency.”

Jussi Venäläinen, Vice President, Filtration business line at Metso Outotec, added: “Eldorado Gold and Hellas Gold were looking for a reliable partner to help ensure the safety and sustainability of the Skouries tailings dry stacking facility. We are pleased having been chosen to deliver this core technology for the project. Previously, we’ve supplied proprietary technologies for grinding, flotation, thickening and automation to Skouries.”

The value of the order is approximately €14 million ($13.8 million), according to Metso Outotec.

Metso Outotec says its filtration product portfolio is the largest in the field, with the company having carried out over 14,000 filtration tests and delivered more than 5,000 filters for various applications worldwide.

A 2021 feasibility study on Skouries highlighted a 20-year operation able to produce 140,000 oz/y of gold and 67 MIb (30,391 t) of copper.

Eldorado Gold’s Efemçukuru mine to test Normet battery-electric vehicle

Eldorado Gold’s underground mining battery-electric vehicle journey is set to begin next month, with the company imminently awaiting the arrival of a Normet SmartDrive concrete transportation vehicle at its Efemçukuru gold mine.

The company has reviewed the potential for the use of battery-electric vehicles at its Lamaque underground gold mine in Canada in the past, but this is the first official trial of zero emission mobile equipment the company will conduct. This aligns with the company’s recently announced target of mitigating GHG emissions by 30%, from 2020 levels, by 2030 on a ‘business as usual’ basis; equal to approximately 65,000 t of carbon dioxide equivalent. To achieve this target Eldorado is focused on pursuing decarbonisation through four key pathways including: measuring and monitoring; operational efficiencies and continuous improvement; technologies, processes and energy generation; and energy procurement and strategy.

Set to arrive at the mine, in Izmir Province, western Turkey, at the end of the month, the Normet Utimec MF 500 SD transmixer will be tested in a combination of ramp and flat drifts over the latter part of April.

Efemçukuru, a high-grade epithermal deposit, will provide a good test for the machine. While reasonably shallow in terms of depth, the narrow-vein mine has four declines (SOS, MOS, NOS and KBNW), each covering approximately 400 m of strike extent. These declines have 15% inclination, while flat drifts with inclinations ranging from 0-5% will provide a good platform for overall speed.

A spokesperson for the gold miner told IM that the machine, which has already been purchased, will be tested against assumptions provided by the manufacturer for rates of charging and discharging. The machine is then intended to be used in an operational capacity.

“Battery charging rates will be tested for charging from the existing grid, from a quick charging station and from downhill braking,” the team leading the project said. “Moreover, the battery usage rate will be tested for driving in uphill (15%) and flat (0-5%) galleries, against assumptions.”

Testing will also involve the comparison of performance of both battery-electric and diesel machines in uphill tramming, with the company expecting the battery-electric transmixer to outperform the diesel-equivalent in these head-to-head tests due to the machine’s high torque.

The Utimec MF 500 Transmixer SD (pictured here at Normet’s outdoor test track at its Iisalmi factory) has a 4.4 cu.m concrete carrying capacity, and comes with a combined power rating of 200 kW alongside a maximum tramming speed of 20 km/h.

Normet says the machine is designed for fast and safe concrete transportation in underground mines and tunnels where the tramming height is at least 2.4 m. The concrete drum rotation is electrically controlled and the speed ranges between 0-13 rpm.

Tested at both the Normet factory and the First Quantum polymetallic Pyhäsalmi mine in Finland, the MF Transmixer 500 SD has displayed a payback period of 2-3 years based on the machine completing a two-hour cycle that involves a 3 km journey on a 1:7 decline running at 15 km/h with the bowl rotating, one hour of unloading with the bowl rotating at 15 kW, and an uphill unloaded haul of 3 km at 10 km/h with no bowl rotation.

Eldorado said the MF Transmixer 500 SD will be at the mine site shortly, with training coordinated by Normet taking place in April ahead of the trial.

Eldorado Gold looks to ARES PRISM project controls software to optimise Lamaque

Eldorado Gold’s Lamaque mine in Quebec, Canada, is set to implement ARES PRISM project controls software to help manage the underground operation.

The mine was seeking a project management tool to provide earned value management, process optimisation and accurate reporting, according to ARES PRISM.

Mehdi Bouanani, Projects and Construction Manager at Eldorado Gold Québec, said: “At Eldorado Gold Québec, we are always looking for innovations and tools to optimise our efficiency. The software ARES PRISM allows us to monitor our costs relating to our various projects closely. In addition, reports that show progress status and execution performance are useful. In general, the software meets our expectations very well.”

Eldorado Gold Québec selected Progesys, a project management firm located in Quebec, Canada, to implement ARES PRISM’s cost management software module, PRISM Cost. Progesys provided training for PRISM Cost users at Eldorado Gold and implemented the software on diverse pilot projects.

Kevin McAleese, Cost Control Specialist at Progesys, said: “By using ARES PRISM, the goal was to streamline the project control processes by centralising all data in one place, standardising and accelerating reporting, and improving the reliability and quality of the data. We implemented it conjointly with Eldorado Gold to make sure that the structure and the systems reflected their specific needs.”

With ARES PRISM, the mining organisation will be able to effectively manage the Lamaque Mine project’s budgeting, resource planning, change management, time-phasing, progress, and performance measurement, earned value management, and forecasting all in a single, central location, according to the software vendor.

Geoffrey Stubson, Chief Financial Officer of ARES Project Management LLC, said: “Eldorado Gold Québec clearly embodies its values of responsibility, integrity and accountability. ARES PRISM will help Eldorado further uphold these values by effectively managing project cost, optimising processes and providing accurate reporting.”

Lamaque began commercial production in March 2019 and is expected to mine and process more than 750,000 t of ore at an average gold grade of 6.6 g/t Au.

Kışladağ and Weir Minerals on the HPGR-backed gold recovery trail

The story that led to the installation of a Weir Minerals Enduron® high pressure grinding roll (HPGR) at Eldorado Gold’s Kışladağ heap leach operation in Turkey is a fascinating read, as well as a great example of the benefits of using such technology.

Back in March 2018, Eldorado announced it would suspend mining to evaluate processing options for the operation. This decision followed extensive laboratory tests that indicated gold recoveries would continue to trend downwards around the base of the open pit where mining was underway.

This suspension, plus further engineering and test work, led to the company advancing the potential development of a mill project. The transition away from its heap leaching roots to a possible mill and carbon-in-leach (CIL) process would have added significant capital costs and shortened the mine life significantly.

Before making this significant capital decision, Eldorado paused to take time to undertake the necessary technical work and sought the technical collaboration of Weir Minerals on a solution.

“It was a very challenging period,” George Burns, President & CEO of Eldorado Gold Corporation, told IM. “Kışladağ is a cornerstone asset in our portfolio. It required collaboration with our geologists, metallurgists, site teams and technology providers, including Weir, working together on a solution.”

(Credit: Eldorado Gold)

In late 2018, results showed increased recoveries from an extended leach cycle. Following a deeper understanding of the geometallurgical drivers of the sulphide component of the deposit, improved heap leach recoveries were realised by optimising the metallurgical conditions. With these improved recoveries confirmed, the heap leach plan was revised in early 2019. Eldorado announced plans to resume mining, crushing, stacking and heap leaching at Kışladağ, and suspended plans to build the processing plant.

The decision came following metallurgical test work on the material placed on the heap leach pad in 2018. Gold recovery had increasingly exceeded expectations throughout the year, providing a new, positive heap leaching outlook beyond the near term. At the same time, Eldorado worked with Weir Minerals on the potential use of an HPGR at the operation.

HPGR creates a finer particle size, which helps to liberate the gold particles, resulting in increased recoveries.

An improved understanding of the leaching process on its low-grade ore and the potential of this cost-effective grinding addition provided it with the confidence to continue heap leaching beyond the short-term time horizon previously envisaged.

“Our collaboration with Weir on this effort is an excellent example of how Eldorado collaborates with technology leaders and seeks out solutions,” Burns said. “We believe this is a strength of the company’s core business values. We are agile and flexible ‒ a good example in both business and operations to find innovative, technical solutions and demonstrate prudent capital discipline. Ultimately, the solution was the best technical and economic decision for Eldorado.”

Testing, testing, testing

“The relationship between Weir Minerals’ and Kışladağ goes back to 2013,” Bjorn Dierx, Global Product Manager Enduron HPGR, told IM.

The OEM had been provided with samples on several occasions to investigate different flowsheet possibilities.

“The benefits of HPGR in heap leaching recovery were known by the site’s crew,” he said.

Enduron technology was tested at the quaternary crushing stage before heap leaching, in the quaternary crushing stage before ball milling and at the tertiary crushing directly before heap leaching.

All the time, the mine operator, Tuprag, Eldorado Gold’s subsidiary in Turkey, was evaluating the impact on gold recovery.

Although HPGR in closed circuit with screening was also tested, most of the test campaigns were focused on a configuration with so-called ‘Partial Product Recycling’ (PPR), according to Serhat Onol, Weir Minerals Senior Process Engineer.

“This system includes splitter plates underneath the rolls which ‘cut’ a proportion of the product discharge and reverts this back to the HPGR head feed,” he explained. “This recycle stream can be adjusted online to adapt the product grind towards the downstream requirements.”

PPR is not an option for every application but for Tuprag – due to the feed and desired product size – all specifications showed it was the best route.

“The hybrid solution with screening serves to increase the flexibility and to control the circulating load to the HPGR,” Onol said.

With capacity rates of around 4,200 t/h at Kışladağ, the screening area requirement was reasonably high, he explained.

“The hybrid solution uses screening only for the recirculating stream: the centre product of the HPGR reports to downstream leaching, whereas the rest is recirculated,” he said. This not only removes the fines re-entering the HPGR and, thus, reduces the circulating load, but also avoids the over-grinding of fines before leaching.

The PPR option, itself, is a very flexible operation, with the adjustable discharge splitter plates providing the best circuit flexibility in terms of throughput and product size, according to Onol.

(Credit: Eldorado Gold)

Great expectations

With the main driver of the HPGR installation being an improved gold recovery scenario, leading to an increased heap leach life, the pressure has been on Weir Minerals to come up with the goods.

The final flowsheet, which includes a 2.4 m diameter by 2.2 m long Enduron HPGR with the capacity to process 4,200 t/h, is much simpler than the existing circuit, according to Dierx, with less equipment to maintain, control and monitor.

“A single Enduron HPGR will replace all of the five existing tertiary crushers of which liners would have an average lifetime of circa-one month with a crusher availability of 85%,” he said. “The HPGR tyres have a wear life close to 18 months, with the HPGR achieving a high asset availability of more than 95%.

“Additionally, as a result of the HPGR combined with the hybrid PPR system, the existing four tertiary screens are also being decommissioned.”

Not only has the HPGR alleviated the use of this equipment, it is also set to boost that bottom line gold recovery.

“During testing, it was determined that the circuit configuration and HPGR operating conditions, such as pressure, have a direct influence on the gold recovery,” Dierx said. “The current expectation is that the average recovery increase after the commissioning of the Enduron solution will be approximately 4%.”

This could bring gold recovery to approximately 56%, as was declared in a 2020 press release from Eldorado that highlighted a 15-year mine life at Kışladağ with an average annual production of 160,000 oz.

In action

One of the largest brownfield HPGRs Weir Minerals has ever installed has just processed its first material at Kışladağ, which is testament to the hurdles both the Weir Minerals and Tuprag teams overcame during the height of the COVID-19 pandemic.

“Despite the challenges we faced during the pandemic, we were able to fully install the machine, including pre-commissioning, in only 22 weeks,” Dierx said.

(Credit: Eldorado Gold)

This was achieved by minimising the amount of work carried out on site via pre-site testing and modular HPGR assembly.

“As the available footprint in existing sites is limited, the unique Enduron design (length:diameter ratio) not only improves the grinding efficiency but also allows for easier implementation with less civil requirements,” Dierx said.

The machine has the potential to be digitally connected to the Weir Synertrex® IoT platform where operators can benefit from direct access to maintenance specialists, who will be monitoring performance and provide necessary operating guidance.

And the Weir Minerals team is confident more Enduron HPGR installations will follow the one at Kışladağ.

“We are very proud of the product’s recognition by our customers as the Enduron HPGR has been selected for all major greenfield HPGR projects in the hard-rock space,” Dierx said. “Despite all the key Enduron differentiators, it is not only merely about the product but particularly the wider experience across Weir Minerals in both the upstream and downstream processes via our wide product portfolio.

“Particularly in these brownfield applications, the system is not operating in a vacuum and every process change influences how the overall circuit works. This requires tacit knowledge, which Weir Minerals holds across their global teams.”

Eldorado’s Burns concluded: “We are pleased to implement a solution that increases gold recovery and supports a 15-year mine life at Kışladağ, allowing Eldorado to continue to provide employment and economic opportunity in the region, as well as provide a solid foundation for future growth.

“Kışladağ has been the cornerstone asset of Eldorado for over a decade, producing over 3 Moz of gold and generating significant value for all stakeholders during that period. This project is a testament to our exceptional team and technology partners working together to execute in challenging circumstances during the pandemic.”

Eldorado Gold green lights underground decline at Lamaque mine

Eldorado Gold is commencing construction of a 3 km decline at its Lamaque underground gold mine in Quebec, Canada.

The fully permitted decline will go from the Sigma mill to the 405 m level of the Triangle mine, where resources and reserves reside.

Eldorado said the $24 million investment was expected to provide multiple near-term and long-term benefits as the company continues to grow production at Lamaque. Earlier this year, it was granted Certificate of Authorization from the Quebec Ministry of Environment to expand underground production from Triangle from 1,800 t/d to 2,650 t/d.

“Detailed engineering and site preparations for the decline will commence this month and surface construction on the portal will begin in Q3 (September quarter) 2020,” the company said.

The decline is expected to be completed by the first half of 2021, but Eldorado is also evaluating the possible addition of an underground crushing and conveying system as well as a potential mill expansion, it said.

Late last year, then-COO, Paul Skayman, told IM the company was considering the use of battery-electric vehicles, or vertical haulage with conveyors, as part of its mine expansion plans.

And, since then, the company has started trialling the SAMS™, or the shallow angle mining system, from Minrail, a system that could allow the company to further enhance Lamaque’s economics, improve safety and develop technical expertise that could potentially be leveraged at some of Eldorado’s other mines.

While an update outlining the path forward at Lamaque is expected in the December quarter of this year, the company said the benefits of the construction of this decline include:

  • Eliminating surface re-handling and haulage (around 26 km round trip) of the ore from the Triangle mine to the Sigma mill, reducing carbon emissions, costs, and removing haulage traffic from the public road network;
  • Reducing the energy requirements for mine ventilation;
  • Supplying a means of secondary egress and ventilation to the Triangle mine, increasing safety underground;
  • Providing underground access for lower cost exploration in the prospective area between the Triangle mine and the historic Sigma and Lamaque mines – including further drilling of the Plug 4 and Parallel deposit and the Ormaque zone; and
  • Facilitating increased future production from the Triangle mine (contingent on continued reserve expansion) and allowing for mining of the Parallel deposit.

George Burns, Eldorado President and CEO, said: “We are pleased to begin construction of the decline at Lamaque this summer. This is a project that we have been advancing for nearly a year and is another step towards further production growth and continued value creation at Lamaque.”