Tag Archives: Evolution Mining

Evolution enlists RCT and its Guidance Automation tech to transform Red Lake gold mine

Evolution Mining has selected RCT and its ControlMaster® Guidance Automation technology to help “transform” its new Red Lake mine in Ontario, Canada.

Evolution has embarked on a three-year investment strategy to restore the newly acquired Red Lake mine to a safe, highly efficient, long life and low-cost operation providing strong value for shareholders. This followed its acquisition of the operation from Newmont in November 2019 in a deal that could eventually rise to $475 million.

RCT has previously worked with Evolution Mining on transitioning its Mungari operations in Western Australia’s Goldfields region to its fully-autonomous technology solution.

To assist in the Red Lake turnaround strategy, RCT will commission its interoperable and scalable ControlMaster Guidance Automation technology to the underground loader fleet.

RCT says it is working closely with Red Lake’s leadership team to seamlessly integrate the new technology to enable greater productivity efficiencies to support Evolution Mining’s transformation strategy.

“The technology will unlock significant value for Evolution Mining by ensuring optimal machine performance, higher speed autonomous tramming, and reduced machine damage,” RCT said. “The technology will deliver faster production cycle times and reduced unplanned downtime across the loader fleet.”

The loaders will be controlled from either the surface-based ControlMaster Automation Centre or the customised underground Automation Centres designed specifically for easier transfer via the mine shaft hoist system.

This solution safeguards machine operators by relocating them away from hazards commonly found at the mine face and significantly reduces shift handover times, lowering overhead costs and resulting in greater site efficiencies, RCT said.

Kirsty Liddicoat, Red Lake General Manager, said: “We are very pleased to be partnering with RCT to introduce modern technologies to Red Lake as part of our transformation process. RCT equipment will enable higher productivity and efficiencies from our underground scoop fleet, while improving safety for our people.”

RCT’s Mining Business Development Manager, Ryan Noden, said ControlMaster is an ideal solution to help deliver the operational transformation that is aligned to Evolution Mining’s Red Lake strategy.

“The advanced features of the ControlMaster Automation technology means Red Lake will be able to quickly achieve improved production efficiencies from its loader fleet, with a greater level of safety for its operators,” he said. “Red Lake will also benefit from selecting a truly interoperable technology provider that can collaborate closely with them to realise further mobile equipment automation opportunities as further optimisation of the asset is achieved.”

Noden added: “RCT has a proud history of delivering value to the Canadian mining sector and we look forward to continually delivering to them with our cutting-edge technology backed by our dedicated in-country support team based at the company’s facility in Sudbury, Ontario.”

Evolution’s vision is to restore Red Lake to be one of Canada’s premier gold mines sustainably producing 300,000-500,000 oz/y of low-cost gold, Jake Klein, Evolution’s Executive Chairman, has said.

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.

DDH1 drilling contractor debuts on ASX after stellar IPO

DDH1 Ltd has officially commenced trading on the Australian Securities Exchange following an initial public offering last week that saw the drilling contractor secure gross proceeds of A$150 million ($115 million) through the issue of around 40% of its shares.

The IPO proceeds were used to allow existing shareholders to realise part of their investment in the company and to repay company borrowings, the company said. The IPO was one of the largest by a Western Australia-based business in the past decade, according to DDH1.

“The ASX listing marks a significant milestone in the evolution of DDH1, which was established in Perth in 2006 with the vision to create Australia’s premier mineral drilling contractor,” the company said. “Over time, DDH1 has earned the custom of Australia’s premier mining companies through its repeated and meticulous service offering of gathering the critical geological data that supports the decision making in respect of all mining activity through the complete cycle of a mine’s life.”

DDH1 has a portfolio of approximately 102 clients, with a financial year 2020 pro-forma revenue of A$249.8 million. Its earnings are diversified across multiple commodities and geographies, with a client base that includes Newcrest Mining, BHP, Evolution Mining, Gold Fields, Independence Group, Kalgoorlie Consolidated Gold Mines, Newmont Corp, Ramelius Resources, Rio Tinto, Roy Hill Iron Ore and St Barbara.

It offers both surface and underground drilling services, with diamond coring and reverse circulation rigs on offer.

Sy Van Dyk, DDH1’s Managing Director and CEO, said: “The growth and success of DDH1 to date is testament to the commitment of the whole team, which strives to ensure the safety of all stakeholders while delivering exceptional service to our clients.

“Our long-term client relationships are built on the provision of quality drilling services and a deep understanding of our client’s business needs. The company’s significant market position reinforces the strong levels of industry recognition.”

He concluded: “There is growing demand in the Australian mineral drilling sector for DDH1’s services because of increased exploration, development and production spending by minerals exploration and mining companies. As an ASX-listed company with a strong balance sheet, a committed shareholder base, a disciplined approach to growth and access to capital markets, DDH1 is well positioned to pursue its growth strategy.”

Evolution Mining’s Red Lake transformation taking shape with CYD decline

Evolution Mining’s transformation plans at the Red Lake gold mine in Ontario, Canada, are tracking ahead of schedule with the Australia-based company’s board signing off the development of a surface decline at the operation.

The company acquired the Red Lake Complex from Newmont in November 2019 in a deal that could eventually rise to $475 million. When the deal was completed, it committed to invest $100 million on existing operations and an additional $50 million in exploration at Red Lake over the first three-year period following completion of the transaction.

The company says the surface decline, which is expected to cost A$60-A$70 million ($47-55 million), will provide a near-term opportunity to access additional low-cost ounces in the Upper Campbell mine at Red Lake with two additional mining fronts independent of the current shaft-constrained infrastructure.

The decline has been named the Campbell Young Dickenson (CYD) in recognition of three early developers of the Red Lake deposit, Evolution said.

Red Lake currently hosts a total reserve of 2.93 Moz at an average grade of 6.9 g/t gold. The decline will enable access to the Upper Campbell area of the mine, which hosts reserves of 1.85 Moz at an average grade of 7.4 g/t Au. Access to the HG Young orebody will also be established, which hosts a resource of 427,000 oz at 5.5 g/t Au and has the potential to be converted to reserves with additional drilling, Evolution said.

 

Annual gold production rates from these additional mining fronts are expected to be in excess of 1 Mt, according to the company.

With regulatory approval for this decline already in place, the box cut is expected to be completed in the March 2021 quarter. It will be located proximal to the Campbell mill.

Following this, development activities are scheduled to commence in the June 2021 quarter and first ore is currently expected in the June 2022 quarter. Studies are ongoing to assess opportunities to accelerate development and ultimate access to first ore, the company said.

Evolution’s stage 1 transformation plan at Red Lake is to cement production of plus-200,000 oz/y at an all-in sustaining cost of less than $1,000/oz by 2023. As part of this program, it has already decommissioned around 70 pieces of underground equipment and completed the phase 1 “hoist automation project” among other things.

Jake Klein, Evolution’s Executive Chairman, said on February 17: “Red Lake has consistently exceeded our expectations in almost every respect. With today’s announcement of the 2.93 Moz gold JORC Code ore reserve and board approval for the decline development, we are excited about the continued momentum we are building at this operation.

“This commitment is a significant step towards achieving Evolution’s vision of restoring Red Lake to be one of Canada’s premier gold mines sustainably producing 300,000-500,000 oz per annum of low-cost gold.”

Emesent builds mining connections as Hovermap autonomy takes off

Having recently helped DJI’s M300 drone fly autonomously underground (through its Hovermap Autonomy Level 2 (AL2) solution) and signed an agreement with Deswik to provide surveyors and planners with more accurate data from inaccessible areas, Emesent has been on a roll of late. IM put some questions to CEO, Dr Stefan Hrabar, to find out more.

IM: First off, if no communications infrastructure is in place at an underground mine, how do Emesent’s drones stream a 3D map of the environment back to the operator’s tablet?

SH: Hovermap is smartly designed to operate beyond the communication range of the operator. The operator does not always need to see a live map since Hovermap is navigating by itself. The user can place a waypoint beyond the current limits of the map, and beyond line of sight and communication range. Hovermap self-navigates towards the waypoint, avoiding obstacles and building the map as it goes. Once it reaches the waypoint (or if the waypoint is impossible to reach), it automatically returns back to the operator. The map data is stored onboard Hovermap and when it returns back to within Wi-Fi range the new map data is uploaded to the tablet. The operator can then see the new areas that were mapped and place a new waypoint in or beyond that map, sending the drone back out again to explore further.

IM: What results have you so far received from using AL2 for Hovermap at mine sites? Were the results PYBAR got from trials at Dargues and Woodlawn in line with your expectations?

SH: Last year’s trials at Dargues and Woodlawn showcased some great outcomes for the PYBAR team, including the ability for Hovermap to capture valuable data using Autonomy Level 1 (AL1). The team saw great potential in the technology, leading to the purchase of two systems for their use. Earlier this year, AL2 flights were conducted at Dargues during the final pre-release testing phase. Even the first stope at Dargues that was mapped using AL2 highlighted the benefit of the system over traditional CMS (cavity monitoring systems). A large area of overbreak was identified in the Hovermap scan. The same stope had been mapped with a CMS, but this area was not visible from the CMS scan location so the overbreak was not identified.

A number of mines have been using AL2 to map their stopes and other areas beyond line-of-sight. With AL2, they can send Hovermap into places that previously would have been inaccessible, enabling them to obtain critical data in real time without risking the machine or personnel.

The AL2-based stope scans have been more detailed and complete (lack of shadowing) than ever before. A beyond line-of-sight flight down an ore pass was also conducted recently, with Hovermap guiding the drone down 120 m and returning safely to produce a very detailed scan.

The high level of autonomy provided by AL2 also allows remote operation of the drone. We recently completed a trans-continental demo, with a customer in South Africa operating a drone in Australia using our AL2 technology and standard remote collaboration tools. The remote operator in South Africa was able to use their laptop to experiment with the technology from the other side of the world, sending Hovermap exploring down a tunnel.

This is a taste of what’s to come, with drones underground being operated from the surface or from remote operation centres thousands of kilometers away. This will remove the need for skilled personnel on site, and reduce the time spent underground.

IM: What had been holding you back from achieving AL2 with drones/payloads? Is it the on-board computing power needed to that has been the issue?

SH: Flying underground where there is no GPS, the space is tight and there are hazards such as mesh, wires, dripping water and dust is very challenging. We overcame many of these with AL1, which makes it safe and easy for a pilot to operate the drone within line-of-sight (Hovermap provides collision avoidance, position hold and velocity control). AL1 has been deployed for 18 months with many customers around the world, clocking up thousands of hours of use. This helped to improve the robustness and reliability of the core flight capabilities.

Emesent CEO, Dr Stefan Hrabar

AL2 builds on this mission-proved base capability to provide additional features. AL2 allows the system to fly beyond line-of-sight and beyond commination range. This means it’s on its own with no help from the operator and needs to deal with any situation it comes across. There are many edge cases that need to be considered, addressed and thoroughly tested. A significant amount of effort was put into these areas to ensure Hovermap with AL2 is extremely robust in these challenging environments. For example, the drone downwash can kick up dust, blinding the LiDAR sensor. We’ve implemented a way to deal with this, to bring the drone home safely. Other considerations are returning in a safe and efficient way when the battery is running low, or what to do if waypoints cannot be reached.

IM: How do you anticipate your partnership with Deswik impacting the mine planning and survey process? Do you see this reducing the amount of time needed to carry out this work, as well as potentially cutting the costs associated with it? Have you already carried out work at mine sites that has proven these benefits?

SH: Our commitment is to help mining companies increase safety and production while reducing costs and downtime. We do this by providing surveyors and planners with more accurate data from inaccessible areas, allowing them to derive new insights. Our partnership with Deswik means we’re able to provide a more comprehensive end-to-end solution to the industry.

We see this as a very natural partnership that will improve the overall customer experience. Hovermap excels at capturing rich 3D data in all parts of the mine (whether drone based, hand-held, lowered down a shaft on a cable or vehicle mounted). Once the data is captured and converted to 3D, customers need to visualise and interrogate the data to derive insights. This is where Deswik and other mining software vendors come into play. They have powerful software tools for planning, survey, drill and blast, geotechnical mapping and a host of other applications. We’re partnering with these vendors to ensure seamless integration between Hovermap data and their tools. We’re working with them to build automated workflows to import, geo-reference, clean and trim the data, and convert it into formats that are suitable for various tasks.

Surveyors at Evolution Mining’s Mungari operation have been using this new process in Deswik. Previously they needed a third software tool to perform part of the workflow manually before importing to Dewik.CAD. The intermediate steps have been eliminated and others have been automated, reducing the time from more than 30 minutes per scan to five minutes per scan.

IM: Since really starting to catch on in the mining sector in the last five years, drones have gone from carrying out simple open-pit surveys and surveillance to drill and blasting reconciliation platforms to reconnaissance solutions carrying out some of the riskiest tasks in underground mining. In the next decade, how do you see them further evolving? What new tasks could drones carry out to improve safety, cut costs or increase productivity?

SH: Emesent’s vision is to drive forward the development of ‘Sentient Digital Twins’ of industrial sites to future-proof the world’s major industries, from mining to energy and construction. These industries will be able to move to more automated decision-making using high-quality, autonomously collected data across their sites and tapping into thousands of data points to make split-second decisions about potential dangers, opportunities and efficiencies using a centralised decision-making platform.

We see our Hovermap technology being a key enabler for this future. Drones and other autonomous systems will become an integral part of the mine of the future. Drones will be permanently stationed underground and operated remotely, ready for routine data collection flights or to be deployed as needed after an incident.

Hovermap is already addressing some of the biggest challenges in mining — including safety and operational downtime. It improves critical safety to mines, keeping workers away from hazardous environments while providing better data to inform safety related decisions such as the level of ground support needed. This then feeds into better efficiency by helping mines to more accurately calculate risks and opportunities, aid decision making and predict situations.

Hovermap can significantly reduce downtime after an incident. For example, it was used to assess the level of damage in LKAB’s Kiruna mine after a seismic event. More than 30 scans were captured covering 1.2 km of underground drives that were not safe to access due to fall of ground. In another case, one of our customers saved around A$20 million ($14.6 million) after an incident, as they could use Hovermap to quickly capture the data necessary to make a critical decision.

IM: In terms of R&D, what future payload developments are you investing in currently that may have applications in mining?

SH: We’ll keep adapting our Hovermap design to suit new LiDAR improvements as they are released. More importantly, we’ll improve the autonomy capabilities so that even more challenging areas can be mapped with ease. We’re also adding additional sensors such as cameras, as these provide additional insights not visible in the LiDAR data. Our colourisation solution is an add-on module for Hovermap, which uses GoPro video to add colour to the LiDAR scans. This allows the identification of geological and other features.

RCT helps Evolution Mining transition to fully-autonomous operations at Mungari

RCT says it has successfully commissioned Evolution Mining’s underground LHD fleet at the Mungari gold mine with RCT’s proprietary ControlMaster® automation technology.

The project has transformed Evolution Mining’s underground loader fleet away from its previous teleremote provider in favour of RCT’s fully-autonomous technology solution, RCT says.

RCT installed and commissioned its ControlMaster Guidance Automation solution onto one CAT R2900 underground loader and one CAT R1700 underground loader at the Mungari operation in Western Australia’s Goldfields.

RCT supplied two Automation Centres located at designated work zones within the mine fitted with G-Dash and provides the operators with real-time, graphical machine data.

The project also involved installing a communications network, critical spares parts and a specialised RCT parts cabinet, according to the company.

Ryan Noden, RCT Business Development Manager Mining, said he was pleased RCT had continued to build on its existing relationship with Evolution Mining.

“RCT’s automation solution was previously established at one of Evolution Mining’s other projects and is now helping the Mungari operation further optimise production capabilities,” Noden said.

“We have been working with Evolution Mining for the past few months planning the transition to RCT’s automation solution that will deliver strong productivity gains.

“Our ControlMaster Guidance Automation technology sets Evolution Mining onto a pathway to full mine digitisation with the ability to scale our technology as the mine develops and introduce the latest technology upgrades when required.

“Mungari will receive on-ground technical support through our branch in Kalgoorlie backed by a team of highly experienced automation specialists.”

A spokesperson for Evolution Mining said: “Evolution Mining has seen a dramatic reduction in remote-related machine damage and a huge improvement in operator comfort and workplace enjoyment. It’s wonderful to see Evolution Mining providing state-of-the-art facilities for its employees.”

RCT will also empower site personnel with comprehensive on-site training packages for machine operators and maintenance personnel, it said.

CSIRO-Gekko’s OLGA proves its worth at Evolution’s Mt Carlton mine

Gekko Systems says the benefits of accessing real-time on-stream gold data has been proven with the trial installation of the CSIRO-Gekko OLGA analyser at Evolution’s Mt Carlton operation, in Queensland, Australia.

This trial has since been converted into a sale and permanent installation, Gekko said.

OLGA is an X-ray fluorescence-based technology capable of detecting gold in slurry with around 1,000-times better accuracy than conventional methods – and in real time, according to CSIRO, which helped develop the analyser.

It detects gold (and other elements) contained in a continuous process stream at 10 parts per billion using a pair of X-ray lenses that greatly magnify the slurry’s fluorescent gold signal as it passes through a tank, CSIRO explained.

While the announcement of the trial and commercial transaction for Evolution’s Mt Carlton operation is ‘news’, CSIRO reported earlier this year that field trials at a Queensland gold mine were showing positive results and that the technology was expected to be ready for market this year.

Gekko, last week, said the unit was installed in December 2018 and trialled on a number of slurry streams including feed and tail before the device was purchased in June 2019. “Both CSIRO and Gekko teams worked collaboratively with a very engaged support group from Mt Carlton to deliver a quality outcome,” the company added.

The alpha system was designed for harsh mine conditions and exhibited high availabilities, according to Gekko. Furthermore, sampling accuracy has also been very positive when compared with assay test work on the same sample stream, the company added.

In reviewing the data, Professor Tim Napier-Munn, a Statistical Expert from JK Tech, said: “Based on these data and in this application, OLGA is likely to provide estimates of feed Au concentration that are suitable for use in manual or automatic control of the downstream process, and metallurgical balancing over time”

Mt Carlton was developed by Evolution and commissioned in 2013 and is now one of the highest-grade open-pit gold mines in the world, according to the miner. It produced more than 100,000 oz of gold for the third year in a row in the company’s 2019 financial year (106,646 oz), the same year in which the development of an underground mine from within the open pit was approved.

Last week, Gekko also announced the signing of a partnership and collaboration agreement with Western Australia-based specialist mineral processing engineers, Cadia Systems. The partnership was expected to feature a new Gekko-Cadia brand, which represented an important industry collaboration between Cadia’s engineering capabilities and technical knowledge in areas such as carbon desorption, regeneration and gold room systems and Gekko’s modular plant and package offerings, the two said.

CSIRO mine wastewater treatment research undergoes Evolution

CSIRO scientists are using microbes and other methods to remove valuable metals and other contaminants from mine wastewater – making remediation pay, the research company says.

And, after testing it out in the lab, CSIRO is now working with Evolution Mining to develop better treatment solutions for the wastewater at the company’s Mt Rawdon gold mining operation in Queensland.

These technologies can process water so it’s pure enough to be safely returned to the environment. It can also be recycled and reused in mine production, according to CSIRO.

CSIRO’s Anna Kaksonen, who leads the research group working in biotechnology for water quality, said: “Certain microbes can help to either oxidise or reduce metals or other compounds, like sulphate, nitrate or selenate, so we can remove them from water.

“Microbes can also be used to clean up organic impurities and reduce acidity or alkalinity.

“For example, wastewater from the alumina industry has a lot of organic impurities that can accumulate in the water used in ore processing.”

Biological treatment can be combined with other processes like hydrotalcite precipitation, delivering a more effective clean-up than either process can alone, according to CSIRO.

The hydrotalcite (an anionic clay) precipitation process invented by CSIRO’s Grant Douglas, and licensed to Virtual Curtain Ltd, involves adding patented mixture into the wastewater, which then binds to metals and other contaminants as it forms hydrotalcite.

“Contaminants are easily removed from the wastewater as a well-settling sludge containing valuable metals in highly concentrated compounds. Adding biological processes after the hydrotalcite precipitation can remove other contaminants remaining in the water, such as sulphate and nitrate,” the organisation said.

Kaksonen says the biological technology often uses bacteria and archaea, which is another type of prokaryotic microbe. Some treatment processes use plant materials or even wetland plants to provide a continuous carbon and energy source for the microbes. These biotechnologies mimic natural systems, but are designed to provide optimum conditions to clean up wastewater.

CSIRO Senior Research Scientist, Dr Ka Yu Cheng, said: “Most of our work has two dimensions.

“First, we aim to understand how the biology works in the environment now.

“Second, we try to engineer the process so that microbes can work better to achieve what we want them to do – such as finding the right mix of plants, the right temperature or the right pH to increase the activity of the microbial community.”

The CSIRO team uses DNA analysis to identify the type of microbes that exist in mine water. They then search through large databases to identify more information about these tiny helpers.

The team also do their own “bio prospecting” – exploring various places in both natural environments and in contaminated sites, to find microbes that thrive in harsh environments, according to CSIRO.

“We take samples from mine sites, existing wastewater treatment processes or sediments,” Dr Kaksonen said.

Team members also look for suitable organic solid or liquid waste streams, such as the glycerol waste from biodiesel production that could be used to drive biotechnical mine water treatment.

“There could be some synergies for using waste from one industrial sector as a feedstock for another sector,” Dr Kaksonen said.

“For example, industrial symbiosis could happen between biodiesel and mining industries, moving both industries toward a more circular economy.”

The CSIRO team recently tested their biotechnology processes in the laboratory on mine water. They are now working with Evolution to develop better treatment solutions for the wastewater at Mt Rawdon.

Dr Cheng said: “The company is planning to use a wetland system to treat mine wastewater. CSIRO’s team will compare the effectiveness of sawdust, plant material, ethanol and lactate to find the best material that can support the microbial treatment in a wetland-like system.”

Dr Kaksonen added: “The mine wastewater from Evolution’s mine will contain sulphate and metals, so we are working with the company to combine hydrotalcite precipitation and biological sulphate reduction.”

The Mt Rawdon gold deposit is a massive, volcaniclastic hosted, low-grade gold deposit that exhibits excellent characteristics conducive to low cost mining and treatment, according to Evolution Mining. The operation is one of its most reliable mines, having produced more than 1.5 Moz of gold since first production in 2001.

Dr Kaksonen said: “While some mining companies have used wetland systems and have trialled various biotechnical processes, most mine sites still use chemical treatments to clean up mine water.”

A constructed wetland could potentially be a cost-effective process to treat water to a stage where it is safe to release back into the environment. The wetland could be constructed while the mine is operating and form a part of the mine closure plan, CSIRO said.

“Biotechnical processes have many advantages when compared to traditional chemical treatments,” Dr Kaksonen said.

One example is that sulphate-reduction based bioprocesses can form metal sulphides – instead of the hydroxides that form in traditional treatments – making it much easier to remove cleaner water from the mix.

“Because metals can be more easily recovered from sulphides, and bioprocesses can use organic waste streams, these techniques also reduce operating costs,” Dr Kaksonen said.

CSIRO said: “The processes that the CSIRO team is developing could herald a revolution in mining remediation – making effective mine wastewater treatment an economic imperative, as well as an environmental one.”

Evolution weighs new Cracow gold mine plan following Minnovare Production Optimiser trial

A close to six-month trial at Evolution Mining’s Cracow underground gold mine in Queensland, Australia, has shown Minnovare’s Production Optimiser technology can have a significant positive impact on ore dilution.

In a newly released whitepaper, co-authored by Evolution Mining, the company compared the use of Minnovare’s new technology with the existing rig setup processes and technology Cracow normally uses (either an onboard digital inclinometer or handheld device).

With drilling conducted on 28 stopes (17 with the new technology and 11 with the existing process) for around six months from July to December 2017, the trial showed the Production Optimiser technology recorded 62% less average dilution than stopes drilled using the existing process. This equated to 11.7% overall dilution, compared with 28.9%, respectively.

The new technology, which was trialled using floating-boom mounted Epiroc 1257 and S7 long-hole rigs and a series of rings/holes drilled as part of the mine’s normal production stoping cycle, was proven to limit rig alignment error, reducing average blasthole deviation and increasing the number of holes drilled within tolerance by 160%, according to the report authors.

They extrapolated this data further and concluded that, if an equivalent reduction in dilution were applied to Cracow’s full year 2017 production data to the end of June – when 440,781 t was hauled and 89,496 oz of gold was produced – all things remaining equal, an additional A$8.2 million ($5.9 million) of ore would be recovered, with a A$4.5 million reduction in costs associated with haulage and processing.

As a result, the return per tonne would increase 22%, from A$87/t to A$106/t.

The results were so impressive Evolution is already considering a further rollout of the technology across Cracow.

Evolution Mining’s Phil Jones: “Aside from improving average stope performance, the Production Optimiser has provided us with greater reliability moving forward. With less overall dilution we’re also seeing less variation in dilution across stopes. We now have the confidence to set more ambitious targets, by considering new mine plans and blast patterns that would previously not have been considered.”

Budget dilution going forward at Cracow has already been lowered to approximately 10% in the 2019 financial year to the end of June based on recent successes. This will allow for higher-grade mill throughput and a reduction in mucking, hauling and milling unit costs, the authors said.

Minnovare’s Production Optimiser technology can be implemented on sites running any rig make/model and works independently of the rig’s on-board systems, according to the company.

The system’s hardware engages with Minnovare’s new online client interface, Minnovare CORE, which uses digital drill plans and plods that sync with existing mine-planning software to deliver drill-data capture and analysis capability. The net result, the company says, is a significant improvement in drill and blast efficiency, productivity and responsiveness – throughout the entire operation.

Since release, Minnovare has already signed up Northern Star Resources as a user.