Tag Archives: cyanide

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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.”

DST to help Newmont go cyanide-free with CLEVR agreement

Dundee Sustainable Technologies has entered into a Technology Transfer Licensing Agreement with Newmont for the use of DST’s cyanide-free gold extraction technology, known as the CLEVR Process™.

DST has been in ongoing discussions and technology review with Newmont regarding its CLEVR gold extraction process to evaluate and quantify its applicability on projects selected by Newmont.

Following a successful test work program in the March quarter of this year, Newmont expressed its interest in the execution of such an agreement allowing Newmont to conduct laboratory CLEVR leaching tests in its technical facilities in Englewood, Colorado.

The method used by DST uses no cyanide, produces no toxic liquid or gaseous effluent, and the solid residues are inert, stable and non-acid generating, according to the company.

David Lemieux, President and CEO, said: “We are very pleased to announce this agreement with Newmont which is the culmination of much work and dialogue between our companies. Our collaboration with a global gold producer is the result of years of continuous efforts in developing an innovative and technically sound process for the industry.”

He added: “Today’s announcement is further validation of DST’s CLEVR Process as one of the leading cyanide-free alternatives for the gold industry, and it represents an important milestone in the early-stage adoption and understanding of our technology by a world leading gold company.”

As part of the agreement, DST and Newmont, agreed to:

  • A two-year, non-exclusive licence for the utilisation of CLEVR at the laboratory scale in its Colorado technical facilities with an option to renew, for an additional two-year period under the same terms;
  • Technology implementation support by DST, including all technology laboratory protocols in addition to technical training sessions to initiate and support the technology transfer and practical operations;
  • Ongoing technology support and for DST to review the laboratory test plans, execution, and results conducted by Newmont; and
  • Any process scaling-up requirements, resulting from positive applications of CLEVR, will be conducted jointly with Newmont at DST’s technical facilities in Canada and/or on-site using DST’s technology and engineering group expertise.

The objective of the agreement is to facilitate the adoption, understanding and application of CLEVR on various gold projects being, or to be, developed by Newmont. The agreement was executed on November 25, 2020.

Heritage eyes up Mount Morgan riches, rehabilitation

A partnership between GreenGold Engineering and Heritage Minerals Pty Ltd has plans to return the Mount Morgan gold mine in Queensland, Australia, to some of its former glory by creating a mean and green way to extract gold from its ample tailings deposits.

The cooperation allows Heritage Minerals to develop the project in a proactive program to maximise the best chance of project success, the company says. Heritage admits it has a big task on its hands, facing doubters that have witnessed a string of false starts at Mount Morgan.

The story behind Mount Morgan dates to 1882 when a syndicate was created to open a gold mine at Ironstone Mountain, 39 km south of Rockhampton.

Ironstone Mountain, later renamed Mount Morgan, was originally operated as an open-pit gold mine at the top of the mountain, before being converted to an underground copper and gold mine.

In 1935, it transitioned back to an open-pit operation and continued until the mine closed in 1980. After this, Peko Wallsend Ltd ran a tailings treatment operation from 1982 until 1991, recovering gold from 27 Mt of tailings.

Mount Morgan pioneered many metallurgical processes to cope with the unique properties of the ore over this time. From chlorine leaching in the early days to various flotation and smelting furnace techniques for the copper/gold ore, the Mount Morgan tailings stockpiles have a rich and varied history.

At different stages over the life of the mine, copper was either a bonus or a nuisance. When copper grades were high, copper was a financial benefit; when the copper grade was low, the metal increased the operating cost associated with gold recovery.

This more than century of mining and processing came with consequences.

The pyrite remaining in the mine and tailings dumps is acid-forming and has generated a significant environmental legacy which remains today. This legacy has become the responsibility of the State of Queensland (1993) and is managed by the Department of Natural Resources and Mining’s (DNRM) Abandoned Mines Division.

Despite these environmental liabilities, five companies have come back to Mount Morgan since Peko Wallsend stopped operations in the early-1990s, encouraged by higher yellow metal prices and improved processing options for the refractory ore.

“We’re the sixth company to have a shot at reprocessing the tailings, with none of the companies before us getting past the feasibility study stage into financing,” Peter Mellor, Corporate Secretary at Heritage Minerals, told IM.

All of them were unsuccessful primarily because of the presence of nuisance copper and the high cyanide consumption that comes with removing this, according to Mellor.

The most recent company to try its luck at Mount Morgan is a case in point.

ASX-listed Carbine Resources developed a process flowsheet to remove part of the troublesome copper by acid leaching the tailings and producing copper sulphate. Additional revenue from the production of pyrite concentrate supplemented gold sales.

It was the production of premium quality (50% sulphur) unroasted iron pyrite concentrate that enabled the commencement of the reduction of acid-forming material at Mount Morgan, Carbine said.

Despite coming up with a 1.1 Mt/y blueprint that, in the expanded case, could operate for 20 years and produce 23,000 oz/y of gold, 2,700 t/y of copper sulphate and 200,000 t/y of pyrite concentrate, the plan ultimately fell down on the projected economic returns, negatively impacted by excessive royalty liabilities.

A February 2018 update came with a revised operating model at Mount Morgan showing all-in sustaining costs (AISC) of A$862/oz ($621/oz), A$313/oz higher than the company’s December 2016 feasibility study.

“The increase is due primarily to higher cyanide consumption and lower by-products credits due to a lower pyrite price and the loss of copper sulphate premium associated with a change in the copper products produced,” Carbine explained.

Fresh approach

To be fair to Mellor and the Heritage team, they are not looking to repackage the same project blueprint in a markedly better gold price environment as other companies have been known to attempt. Instead, they are setting up the project and the town of Mount Morgan for a brighter and sustainable future.

After gaining rights to the project from Norton Gold Fields following Carbine’s exit, one of the first things Heritage did was appoint GreenGold to carry out the definitive feasibility study.

Equipped with its ReCYN resin-based technology that has been shown on other projects to reduce cyanide consumption by up to 50% through capturing free cyanide from plant tailings and recycling it back into the leach circuit, the selection was an obvious choice.

The company could potentially detoxify the tailings stream and clean up the water discharge at Mount Morgan. This would be a boon for the DNRM, which currently treats the water from the open pit and tailings deposits before being released into the local creek due to the low pH levels caused by the acid-forming pyrite.

“Our process plant will use this water, treat it and send it out as clean water down the creek,” Mellor explained.

This is one of several changes the company is implementing to make the project viable.

“For example, Carbine were previously looking to float off the nuisance copper at the start, which came with the associated capital costs of building a flotation plant,” Mellor said. “Yet, the copper really represented a low amount of revenue (2,700 t of copper sulphate in the studies) overall.”

The ReCYN resin plant can deal with the higher cyanide consumption needed to treat the copper at the back end of the flowsheet. This will allow the company to focus on the gold – which represents 90% of revenue – that can be processed by a technically-simple carbon in leach plant.

Malcolm Patterson, MD of Heritage Minerals, and Peter Papa, Technical Director of Heritage Minerals, observe the task ahead at Mount Morgan

The open pit is partially filled with previously processed tailings, with Mellor saying the reprocessing of 10 Mt of tailings (averaging 1.1 g/ Au) can help complete the rehabilitation process.

“We have come up with a really neat environmental rehabilitation scenario where we fill the existing open pit up, and cap it all off nicely so the surface water cannot penetrate,” he said.

Set to build a 2 Mt/y plant to re-process this material, Heritage is only looking five years out from first production, although there is potential for this processing quantity to be doubled.

Even with this near-term gaze, the definitive feasibility study (DFS) anticipates a one-year payback and an upfront capital expenditure bill of A$74 million (compared with Carbine’s last A$96 million estimate).

“There is more potential than this,” Mellor says of the feasibility study, highlighting several areas of interest within proximity of the existing open pit. “Yet, we wanted to get the economic, environmental and social aspects ticked off first before laying out any longer-term plans.”

The company has been very thorough in coming up with this five-year plan.

Already blessed with an extensive JORC resource database from previous Mount Morgan tailings reprocessing protagonists, the company continued to drill for tonnage and bulk density definition of the tailings resource; the latter with a Dando percussion drill rig capable of punching 1 m cores down to 30 m depth.

With a board decision on the DFS expected before the end of the year, Heritage could soon enter the financing stage, followed (hopefully) by construction.

If all goes to plan, operations – a simplified earthmoving and processing method – could begin in 2022.

“Mount Morgan is definitely not the easiest site, but it is the most prestigious in terms of history and challenges,” Mellor says.

Heritage and GreenGold will soon be judged by the financing community on whether they are up to such a challenge.

GBM, Round Oak celebrate first gold doré at White Dam

GBM Resources and Round Oak Minerals’ White Dam gold-copper heap leach asset in South Australia, has poured its first gold doré bar.

The achievement follows the completion of the sulphidisation-acidification-recycling-thickening (SART) plant build back in July, which earned GBM its 50% stake in the asset. GBM says the SART plant, and associated copper concentrate production, continues to ramp-up broadly in-line with expectations, while identified optimisation opportunities are expected to drive further expanded production and reduced costs.

White Dam, around 50 km southwest of Broken Hill, is a heap leach operation that, since 2010, has produced about 175,000 oz of gold from heap leaching of 7.5 Mt of ore at 0.94 g/t Au (which was mined from two open pits).

The JV owners say evaluation of the estimated remaining resources of 4.6 Mt grading 0.7 g/t Au for 101,900 oz of gold has commenced to determine the viability of the extraction and leaching of this material.

Peter Rohner, Managing Director and CEO, said: “I would like to thank the Round Oak site team for their ongoing efforts in optimising the SART plant operation. While recent rain has resulted in some minor delays, the additional water is set to drive increased heap leach irrigation and thus higher gold and copper production in the near term.

“We are now working to finalise shipping of the first copper concentrates once the concentrate drying process is completed. The SART plant is meeting its design objectives of removing copper and increasing the recovery of the cyanide solution back into the circuit to increase gold recoveries, which together enhance the overall economics of the White Dam operation.”

Sixth Wave and MPS team up to cut cyanide usage, costs in gold processing

Sixth Wave Innovations says it is working with Australia-based Mining and Process Solutions (MPS) on test work initiatives in North America and Australia integrating Sixth Wave’s commercially available IXOS® molecular imprinted polymer for gold extraction with the MPS GlyCat™ process.

The GlyCat process was invented to reduce cyanide consumption while maintaining gold recovery for gold ores from deposits containing nuisance copper. For gold applications, the IXOS platform, meanwhile, is capable of selectively targeting gold while rejecting contaminants such as copper, mercury, and other non-target elements potentially contained in a gold-bearing cyanide leach solution.

The two companies are also working in collaboration with the Centre Technologique des Résidus Industriels (CTRI) and a top 10 gold producer in Canada. This project aims to develop an environmentally-friendly flowsheet for the gold mining industry, examining MPS’ acidic and alkaline leaching technologies, together with Sixth Wave’s molecular imprinted IXOS resin technology for the extraction of gold from alternative lixiviants. Testing is to be undertaken on ores provided by the Canadian mining partner, Sixth Wave said.

A recent study published in the Hydrometallurgy Journal titled ‘Gold recovery from cyanide-starved glycine solutions (Glycat) in the presence of Cu using molecularly imprinted polymer IXOS-AuC’ found that “gold recovery increased, while copper recovery decreased with the increasing gold concentration”, Sixth Wave said. The adsorption behaviour of IXOS-AuC had “the best selectivity compared to three other gold selective resins”, the study added. Other outcomes from the study showed the IXOS-AuC polymer was very robust, allowing reuse without deterioration of the polymer physically (assessed by scanning electron microscopy) or in performance.

“Our collaboration with MPS is an important initiative for Sixth Wave and our IXOS high performance gold extraction products,” Dr Jon Gluckman, President & CEO of Sixth Wave, said. “The industry is keenly interested in new and innovative approaches to leach and recover gold as a replacement, in whole or in part, for conventional processes. In order to focus on lowering capital expenditure and operating expenditure, and to comply with environmental and regulatory constraints, Sixth Wave is extremely interested in leveraging our technology with the benefits of the MPS glycine leaching and recovery process.”

Ivor Bryan, Managing Director of MPS, said: “Our respective technological approaches can bring tremendous value to prospective customers by significantly cutting cyanide usage along with the associated costs and environmental impact.”

Earlier this week, Sixth Wave Innovations signed a non-binding Letter of Intent to trial its IXOS purification polymer at the Rio2 Ltd-owned Fenix gold project in Chile.

Corem’s cyanide recovery and recycling process wins federal, provincial backing

Quebec-based Corem is to receive C$2.1 million ($1.6 million) of funding from the Canadian government to support the development of an innovative process for the recovery and recycling of cyanide in the gold extraction process.

This new process is more environmentally sustainable and reduces the impact of gold mining on the aquatic ecosystem, according to Natural Resources Canada.

The announcement was made by Jean-Yves Duclos, President of Treasury Board of Canada and Member of Parliament for Quebec, on behalf of Seamus O’Regan, Canada’s Minister of Natural Resources. The Quebec Ministry of Energy and Natural Resources is also contributing an additional C$100,000 to this project, according to the government.

Following this cash injection provided through Natural Resources Canada’s Clean Growth Program, Corem will work to accelerate the deployment of the process at commercial scale by constructing a pilot-scale processing plant, NRC said.

“Corem’s promising recycling technology is expected to reduce the volume of contaminated water stored in tailings ponds, thereby contributing to the sustainability and competitiveness of the mining industry,” it added.

Francis Fournier, President and Chief Executive Officer of Corem, said: “This financial support demonstrates the importance and interest in the development of clean technologies for the mining industry and the Government of Canada. It allows Corem to pursue its mission of developing innovative solutions for the benefit of a sustainable mining industry and of working closely with our members, our customers and our partners.”

The Clean Growth Program invests in clean technology research and development projects in Canada’s energy, mining and forest sectors. The program is a C$155 million investment fund that helps emerging clean technologies further reduce their impacts on air, land and water while enhancing competitiveness and creating jobs, it says.

It also provides federal laboratory support for innovators under the Science and Technology Assistance for Cleantech initiative, which is intended to help bring Canadian clean technologies to market by providing federal research expertise, facilities and equipment.

Outotec addresses cyanide consumption with new BIOX refractory gold process

Outotec has introduced its new MesoTHERM BIOX process to significantly reduce cyanide consumption in refractory gold ore treatment.

Traditionally, cyanide consumption with conventional bio-oxidation residues is higher than with residues produced through other oxidative technologies. The Outotec MesoTHERM BIOX® process, based on Outotec’s existing mesophile BIOX process, offers an easy, cost-effective upgrade path that can cut cyanide consumption by as much as 50% compared with conventional bio-oxidation, the company claims.

The BIOX process, which has been in commercial operation for over 30 years, was developed for the pre-treatment of refractory concentrates ahead of conventional cyanide leaching for gold recovery.

“The Outotec MesoTHERM BIOX process enhances the established mesophile BIOX process by combining mesophile bio-oxidation technology with a higher-temperature thermophile oxidative stage to enable an even more effective overall sulphide oxidation step,” Outotec says.

On top of cutting cyanide consumption by as much as 50% compared with conventional bio-oxidation, MesoTHERM BIOX significantly reduces the formation of thiocyanate – a common and stable cyanide species traditionally formed as a further by-product, the company said.

Solubilised species prevalent in the mesophile stage are decanted off in an inter-stage thickening step between the two oxidative processes, simplifying operation of the thermophile stage, the company explained.

For existing BIOX customers, upgrading to BIOX MesoTHERM is a “relatively simple process”, Outotec says. It involves reconfiguring the circuit with the addition of Outotec’s High Rate Thickeners for inter-stage thickening and Outotec OKTOP® Atmospheric Reactors for the thermophile step.

Craig van Buuren, Senior Process Engineer, Outotec, said: “Our conventional mesophile BIOX process has enabled the production of over 25 Moz of gold to date. This novel process takes advantage of these proven technologies to help our customers achieve significant cost savings while also reducing their environmental footprint.”

GreenGold’s ReCYN processing pipeline continues to grow

GreenGold Technology has been making huge waves of late, with its biggest ReCYN resin-based technology build to date nearing completion and several new projects on the horizon.

ReCYN reduces cyanide consumption by up to 50% by capturing free cyanide from plant tailings and recycling it back into the leach circuit while recovering metal complexes and making them available for sale, according to the company. In the process, it detoxifies the tailings stream and guarantees 100%-compliant clean water discharge.

Such technology is in serious demand considering the industry’s operational cost focus, increased stakeholder pressure around the use of cyanide, the need to recycle and replace as much water as possible, and a necessity to improve project economics through the recovery of all payable metals.

On top of this, new and existing gold projects are becoming difficult to process through conventional means with problems around by-products such as copper often proving to be the difference between a sub-economic and economic mine development proposition.

The ReCYN process is based on the use of a functionalised resin bead, pre-treated to allow the dual duty of recovering free and complexed cyanide ions from solution with a high degree of efficiency. GreenGold works with local construction companies to customise treatment plants for each operation to match the various solution chemistries and throughputs, it says.

“The two areas of cyanide recovery and metal detoxification are balanced to achieve the desired compliance levels,” GreenGold says. “Equally applicable to slurries and solutions, the process is technically and economically superior to all others currently available for the detoxification of gold plant tailings.”

The company currently has four ReCYN options for clients, according to Commercial Director, Peter Mellor.

ReCYN I is for active (free) cyanide reduction, while ReCYN II has been devised to include detox applications to recover cyanide complexes such as copper. ReCYN III adds gold recovery as a “secondary function” to the mix.

The fourth option (ReCYN IV) includes gold recovery as a primary option, Mellor told IM, explaining that the development of a plant offering in this configuration could remove the need for a carbon in leach treatment plant in some applications.

It is a ReCYN II installation the company is currently putting the finishing touches to at PT Agincourt Resources’ Martabe gold-silver operation in Sumatra, Indonesia (graphic above).

This project, which will detoxify tailings and recover cyanide and copper, was previously estimated by Whittle Consulting to provide a $126.9 million upside to the project.

Speaking to IM from Australia, Mellor said the company was just over a month away from completing the plant at Martabe before COVID-19 restrictions hit progress. He was confident the company would be back completing plant commissioning before the end of the year.

By far the biggest ReCYN installation of the technology, the ReCYN II plant at Martabe will fit into the 5.5 Mt/y circuit and treat around 1.2 t/d of copper, Mellor said. It will also have benefits in terms of reduced cyanide consumption and improved water quality at the operation.

While work in Indonesia is currently not taking place, the company is making significant progress elsewhere.

Mellor said GreenGold had started detailed engineering for a plant in the Ivory Coast, while it had also completed an economic study on a legacy gold operation in Australia that showed compelling economics and the potential for a ReCYN IV installation for processing gold-bearing tailings.

The company also has some 40 projects it is working on in the laboratory – from Australia to the US – with client awards expected in the next few months.

CyanoGuard receives EU, investor backing for next gen cyanide monitoring solution

Switzerland-based chemtech startup CyanoGuard has completed a fundraising and been awarded a non-dilutive SME Instrument grant by the European Union’s Horizon 2020 program that, it says, will speed up market penetration and develop further applications for its next generation cyanide monitoring solutions.

Established in 2016, CyanoGuard has since developed and commercialised its solutions for gold mining operations, food safety testing and healthcare.

Co-Founders Benedikt Kirchgässler (CEO) and Mathias Cherbuin (CTO) transformed a chemical technology for rapid toxin detection from the labs of the University of Zurich into a “comprehensive digital solution package” that has found its first commercial application in the gold mining industry.

The company has now raised more than CHF3 million ($3.12 million) to help further develop the technology, which CyanoGuard says can minimise cyanide consumption by 12% while maximising extraction efficiency through real-time, instaneous measurement results.

Kirchgässler said: “These funds enable us to scale our ground-breaking monitoring solutions and roll them out to gold mines around the world.

“I am excited about the positive impact that our digital, artificial intelligence-based technology has on the global gold mining industry as well as the local communities and the environment.

“I believe that we will benefit from both the experience of leading venture funds…as well as the support of the European Union to speed up market penetration and develop further applications for our technology.”

With the newly raised capital from this seed round, CyanoGuard plans to accelerate its go-to-market strategy in the global mining industry.

Alex Stöckl, Founding Partner at Wingman Ventures, who has joined CyanoGuard’s Board of Directors following the funding round, added: “With its current offering, CyanoGuard has a unique value proposition for its mining clients that is beyond improved cyanide testing. This encompasses an efficiency-enhancing digitisation of process control and a more sustainable usage of cyanide in mining operations.

“We are convinced that Benedikt, Mathias and their team will drive CyanoGuard to become a globally leading provider of digital mining solutions.”

The freshly obtained funds are also intended to further expedite the development of CyanoGuard’s product offering for food safety and healthcare applications, the company said.