Tag Archives: Cowal

Evolution Mining taps AGL Energy Ltd for new power supply at Cowal

Evolution Mining Limited says it has secured a competitive, long-term power supply agreement for its Cowal gold operation, in New South Wales, Australia, under a new eight year partnership with AGL Energy Limited, commencing in January 2023.

Power costs represent approximately 7% of Evolution’s total costs. This agreement provides ongoing long-term security of power supply to Cowal at competitive pricing which is consistent with Evolution’s previously reported financial year 2023 guidance and financial year 2024 outlook, it said.

This long-term agreement also includes a renewable energy component.

Under the terms of the partnership with AGL, a growing portion of the power will be from renewable sources and provides Evolution a clear pathway to meeting its commitment to reduce energy (Scope 1 and Scope 2) emissions by 30% by 2030, the miner said.

Evolution’s Executive Chair, Jake Klein, said: “This is a very important milestone for Evolution. In a very challenging energy market, we have been able to secure both a long-term, competitively priced power contract for Cowal and a growing renewable component that provides us a clear pathway to reducing our energy emissions by 30% by 2030.

“We will continue to look for new ways to further reduce emissions from our fixed plant and mobile equipment to deliver on our net-zero commitment by 2050.”

AGL General Manager, Commercial and Industrial Customers, Ryan Warburton, said: “AGL has been working with Evolution Mining for a tailored solution for their Cowal Gold Mine to help lower their energy costs, provide ongoing long-term security of power supply and assist in reducing their carbon emissions.

“From leading food, agri-business and now to gold mines, AGL is working with our customers to develop bespoke renewable energy solutions to meet their changing needs. This announcement with Evolution Mining is another great example of how AGL is partnering with industry to help them reduce their carbon emissions and lower their energy costs. Through innovative partnerships like this, we are delivering on a low-carbon future with our customers and communities as we transition towards net zero.”

The Cowal mine produced 227,105 oz of gold in Evolution’s 2022 financial year. The company has a plan to expand production to 350,000 oz/y as the mine goes underground.

Barminco extends relationship with Evolution Mining at Cowal gold mine

Perenti Group’s underground mining business Barminco is to further strengthen its relationship with Evolution Mining, having been awarded a new A$60 million ($42 million) contract to carry out diamond drill work at Cowal Gold Mine operations in New South Wales, Australia.

The four-year contract will see Barminco use state-of-the-art drill rig technology to improve safety, performance and productivity, it says.

It’s the second contract to be secured by Barminco at the Cowal operations in two months, after recently winning a A$520 million underground and development contract.

This latter contract will see Barminco carry out all underground development and production works at the underground mine where it is currently developing an exploration decline.

Last year, the Evolution board and regulators approved the development of the Cowal Underground Mine, which is set to provide a higher-grade ore source that will be blended with the current E42 open pit and stockpile ore. The development is part of the group’s goal of Cowal producing 350,000 oz/y of low-cost gold and extending the operation’s mine life.

Gekko Systems improves carbon sampling accuracy, safety at Cowal gold mine

The technical team at Gekko Systems has released further data that, it says, supports the benefits of new technology that optimises carbon management systems in gold processing facilities.

Optimising carbon management in the carbon-in-leach (CIL) circuit reduces gold solution losses and improves gold circuit recovery. This is essential for sites needing to offset higher inflationary costs with improved revenue, Gekko says.

The case study, released today, reviews operational performance of Gekko’s Carbon Scout at Evolution’s Cowal Gold Operation in New South Wales, Australia.

The Carbon Scout is a self-contained, ground-level sampling system that measures carbon concentration, as well as pH, DO and, more recently, has an option to measure gold loading on carbon using XRF technology on an hourly basis. Optimising the Carbon Scout for site conditions allows for more accurate, reliable and repeatable measurement of the carbon inventory of the CIL
circuit, Gekko says. Automating data collection and process actions such as carbon transfer, meanwhile, reduces operator risk exposure and person-hours (previously dedicated to the manual data collection tasks).

Installation of the Carbon Scout at Cowal commenced in February 2019, with the Gekko Systems Digital Services and Technical team providing ongoing support – both onsite and remotely – in the initial months of the system’s operation to ensure maximum availability was achieved and Evolution Mining was receiving the full benefit of the Carbon Scout.

After a few months of integration with the SCADA system, the Carbon Scout was able to use the data and analysis to facilitate automated transfer of the carbon inventory within the circuit to maintain pre-determined concentrations, according to Gekko.

The Carbon Scout at Cowal has successfully reduced operator exposure to slurry containing hazardous materials including cyanide and improved sample authenticity by collecting a more representative and repeatable sample, Gekko said in the case study.

The other critical success achieved by the Carbon Scout is its ability to take a larger CIL tank sample that is more representative. This is achieved by the Carbon Scout drawing from deeper within the tank, where more superior slurry-carbon mixing occurs, and a larger sample of up to 20 litres is taken, which is 10-20 times the typical manual sample size. Additionally, the sample is extracted from a consistent point each time the Carbon Scout cycle samples from that tank.

Gekko concluded: “Optimising the Carbon Scout for site conditions allows for more accurate, reliable and repeatable measurement of the carbon inventory of the CIL circuit. Utilising these measurements and integrating with a plant’s SCADA system, the automatic control of carbon concentrations through the CIL circuit can be achieved. Automating data collection and process actions such as carbon transfer reduces operator risk exposure and man hours previously dedicated to the manual data collection tasks.

“The improvement derived from the utilisation of the Carbon Scout should lead to increases in circuit recovery by reducing soluble gold losses.”

The Carbon Scout was originally the brainchild of Curtin University’s Gold Processing team, led by Dr Teresa McGrath and Bill Staunton. Curtin University selected Gekko Systems as its commercialisation partner.

Staunton noted that “real-time data collection instrumentation and related analysis is essential to the future of the gold processing industry”.

Gekko Systems’ Technical Director, Sandy Gray, said: “The increasing installation base of the Carbon Scout globally is providing a fantastic baseline of evidence that supports the benefits of quality data collection and automation.”

Barminco to help Evolution go underground at Cowal gold mine

Perenti’s Barminco underground mining business has been awarded the contract for all underground development and production works for Evolution Mining’s Cowal Underground project in New South Wales, Australia.

Barminco, a leading global underground mining services business, is currently developing an exploration decline and conducting diamond drilling services at Cowal.

Last year, the board and regulators approved the development of the Cowal Underground Mine, which is set to provide a higher-grade ore source that will be blended with the current E42 open pit and stockpile ore. The development is part of the group’s goal of Cowal producing 350,000 oz/y of low-cost gold and extending the operation’s mine life.

Perenti said the award of this new contract significantly expands Barminco’s scope at the site to include the development of a second portal, all underground development and production works, and associated underground mining services required to support the continued mill feed of underground ore.

Mark Norwell, Managing Director and CEO of Perenti, said the award of the Cowal contract aligns with Perenti’s strategy of increasing its earnings in top-tier regions and with top-tier clients.

“The Cowal contract represents one of the largest underground mining projects in Barminco’s history, generating revenue of nearly A$520 million ($373 million) with an initial term of four years, from a contract commencement date in early July 2022,” Norwell said.

“This contract award represents not only a significant expansion and continuation of our first underground contract in New South Wales but is also a fantastic opportunity for Perenti to build on our strong working relationship with Evolution, one of Australia’s premier gold mining companies.”

Norwell explained that, between now and the end of Perenti’s 2022 financial year, the company will commence investing the capital required for this project with revenues and earnings ramping up in the 2023 financial year and beyond.

“The project represents a significant improvement to our Australian underground earnings base and will generate strong project cash flows and returns in support of our capital allocation and investment,” he added.

Evolution Mining studying open-pit, underground expansion options at Cowal

Evolution Mining says it is embarking on a prefeasibility study to further expand its Cowal open-pit mine as part of a plan to build towards 350,000 oz/y of sustainable, reliable, low-cost gold production from the New South Wales operation.

Currently on the E42 stage H cutback, Evolution said during a recent site visit that there is potential to further the life of the open pit by accessing feed from the E41 and E46 satellite pits. The study looking into a possible expansion is due later this year, with the company saying it could provide long-term base load ore feed for the operation.

The mine produced 262,000 ounces in Evolution’s 2020 financial year.

The Stage H cutback the company is currently pursuing is expected to see increased ore volumes and grade mined in the first six months of this year, with the strip ratio to fall below 1:1 in its 2023 financial year, Evolution said. It also says an equipment strategy review is underway, with opportunities to “rationalise fleet” with reduced re-handling.

The haulage and loading fleet at Cowal currently consists of 20 Cat 789C dump trucks, three Cat 785C trucks, four excavators (one Liebherr 9400, one Liebherr 994B, one Liebherr 9200 and one Hitachi EX1200), plus three Cat 992G wheel loaders. It also has six hired Epiroc SmartROC surface drills at the operation, one Drill Rigs Australia GC600 drill rig, five Cat D10T tracked dozers and one Cat 834H wheel dozer.

The open-pit expansion is only part of the expansion story at Cowal, with a feasibility study underway on an underground operation. This is factoring in 3 Moz of resources and 1 Moz of reserves, with high-grade orebodies open at depth, the company says.

A second decline (Galway) is due to be developed at Cowal this year, with diamond drilling set to commence next month. The 14,300 m of planned drilling will, the company says, help confirm optimal grade control parameters and convert resources to reserves.

Evolution Mining also has a permit to increase processing capacity at Cowal to 9.8 Mt/y, with near-term incremental improvements targeting a circa-9 Mt/y rate.

The process flowsheet at Cowal includes primary crushing with a Metso Outotec 54-75 Superior MK-II gyratory, grinding with an FLSmidth 36 ft (11 m) x 20.5 ft (6.2 m) SAG mill and FLSmidth 22 ft x 36.5 ft ball mill, and screening with Schenck and Delkor screens. Sandvik H6800 hydroconecone crushers, Metso Outotec flotation cells, a Metso Outotec Vertimill, and Metso Outotec stirred media detritors also feature.

Evolution also said it is testing technology that uses glycine and cyanide during the cyanidation process of gold ore at Cowal for potential significant cost savings and environmental benefits.

Lab trials with the GlyCat™ technology from Australia-based Mining and Process Solutions have been completed successfully, it said, with the next phase being pilot plant trials to assess variability tests and long-term environmental impacts.