Tag Archives: Curtin University

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.”

FBICRC’s battery value chain plans accelerate with cathode precursor pilot plant launch

The Future Battery Industries Cooperative Research Centre (FBICRC) has launched its flagship project – the Cathode Precursor Production Pilot Plant – in Western Australia.

Backed by 19 industry, research and government participants, the launch represents a major step in Australia’s journey to expand its presence throughout the global battery value chain, it said.

The first of its kind in Australia, the Cathode Precursor Production Pilot Plant will establish the technology and capabilities for Australia to design and build cathode precursor manufacturing facilities on a commercial and industrial scale.

The FBICRC explained: “Cathode precursors are precisely engineered materials, the highest cost component of a cell, and a crucial element of the battery value chain. The FBICRC’s report – ‘Future Charge – Building Australia’s Battery Industries’ – identified establishing an active materials manufacturing capability as an immediate priority for Australia to move up the global value chain, which could deliver A$1 billion ($672 million) to the economy and support 4,800 jobs by 2030.”

The Cathode Precursor Production Pilot Plant capitalises on Australia’s strong position in mining and its emerging battery metal refining industry. The facility will link with other FBICRC flagship projects across Australia, including the National Battery Testing Centre at the Queensland University of Technology, battery materials research at the University of Technology Sydney, electrolyte research at Deakin University and battery anode research at the University of Melbourne.

Shannon O’Rourke, CEO of the FBICRC, said: “The launch of the Cathode Precursor Production Pilot Plant is the culmination of several years of hard work, collaboration and integration by industry-leading partners and academic institutions, to progress the current and future needs of industry. We’re delighted to see this world-class facility up and running.

“The incoming government has committed to a National Battery Strategy which will help to seize local battery manufacturing opportunities. The Cathode Precursor Production Pilot Plant will be a key enabler to build an Australian manufacturing capability.”

The global battery market is expected to grow 9-10 times by 2030 and 40-fold by 2050. In a net-zero world, between now and 2050 over A$23 trillion will be spent on batteries, according to the FBICRC. Australia is positioned to capture more of this value given it has leading resources of all raw materials required to make high performance batteries – nickel, cobalt, manganese, graphite and lithium.

Cathode precursor materials are further processed to create cathodes in the battery cell. The performance, durability, safety, and operating envelope of a cell are impacted by the properties of precursor materials. Composition, shape, and surface properties must be controlled closely to ensure a cell performs reliably over many years.

Over 18-months, the plant will run a series of test campaigns through four fully integrated and automated P-CAM production units, provided by BASF. The four units will enable the Cathode Precursor Production Pilot Plant to run different compositions and ratios of chemistries simultaneously, or to run the same chemistries under four different conditions, changing variables such as temperature, pH or stirring rate. Produced P-CAM is then lithiated, calcined and electrochemically tested at the FBICRC-funded Electrochemical Testing Facility at the Queensland University of Technology.

BHP Nickel West has also provided equipment for the precursor facility, repurposed from its nickel sulphate pilot plant.

The Cathode Precursor Production Pilot Plant will not only deliver the technical capabilities required to build commercial scale P-CAM manufacturing facilities, it will help educate and upskill the next generation for a future battery industry, it said.

O’Rourke concluded: “Australia has the potential to develop into a competitive player in the international batteries industry. The Pilot Plant launch is a significant step in developing the on-shore capabilities and industry knowledge to create thousands of jobs and add billions of dollars to our economy.”

Jessica Farrell, Asset President, Nickel West, said: “The launch of the Cathode Precursor Pilot Plant is a vital step towards developing a future growth industry here in Western Australia. The launch of this plant, made possible through the repurposing of equipment from our nickel sulphate pilot plant, will allow the FBICRC and the State Government to explore further options for a downstream battery materials manufacturing industry. This is another exciting step for BHP as a major supplier of nickel, a commodity highly sought after by car and battery manufactures across the globe.”

Project participants include: BASF Australia Limited, BHP Nickel West, Queensland University of Technology, Curtin University, CSIRO, Minerals Research Institute of Western Australia, University of Technology Sydney, HEC Group Pty Ltd, JordProxa Pty Ltd, Ardea Resources Limited, IGO Limited, Blackstone Minerals Limited, Cobalt Blue Holdings Limited, Calix Limited, Alpha HPA Limited, Lycopodium Limited, ChemX Materials Limited, EV Metals Group PLC and Allkem Ltd (formerly Galaxy Resources Limited).

Draslovka eyes base metal leaching prize with MPS glycine technology

Draslovka Holding made its presence felt in the mining chemicals space about a year ago when it announced plans to acquire Chemours Company’s Mining Solutions business, a deal that has since seen it become one of the largest North American producers of solid sodium cyanide.

This acquisition, completed in December for $521 million, also laid the groundwork for a separate transaction that could see the Czech Republic-based company diversify into the in-demand battery metals arena.

Australia-based Mining & Process Solutions (MPS) had been on the Mining Solutions business radar for at least two years prior to the Draslovka transaction, according to James Stockbridge, Director of Draslovka Mining Solutions. Stockbridge, formerly of Chemours and DuPont, said that his team at Draslovka realised MPS had something on its books that could solve many of the challenges the industry was experiencing and transform mining solutions by using an amino acid called glycine.

“For more than a decade now, the industry has recognised that orebodies are becoming lower grade, processing them is becoming more complex and the environmental regulations associated with leaching are becoming stricter,” Stockbridge told IM.

“It is the challenge of our time, and we think MPS has something quite unique to offer here.”

With roots in the gold technology group at the renowned Curtin University in Western Australia, MPS’ glycine leaching technology has the potential to change both the gold and base metal leaching space.

In gold, MPS’ GlyCat™ process was invented to reduce cyanide consumption while maintaining gold recovery for gold ores from deposits containing nuisance copper. GlyCat has been designed to enhance the dissolution of gold and copper in gold/copper ores where glycine is used as a catalyst with cyanide in a cyanide-starved leaching environment. It doesn’t replace cyanide, but, in fact, enhances its leaching capabilities by dealing with the high-cyanide consuming copper within these gold-copper orebodies.

In copper, nickel, cobalt and zinc leaching, GlyLeach™ is able to leach the targeted metals with enhanced selectivity compared with conventional methods. It will solubilise copper, nickel, cobalt and zinc, while gangue minerals such as iron, manganese, silicates and carbonates remain in the leach residue, MPS says.

Both technologies are environmentally safe, work effectively at alkaline pHs and ambient temperatures (with no heating cost or pressure vessels) and come with low operating costs due to their low consumption and recovery/recycling traits, according to the company.

While it is the gold side of glycine leaching testing that has, so far, taken the headlines thanks to several trials with mining companies in Australia (including Evolution Mining) and the technology’s potential ability to partially replace cyanide in the leaching process, Stockbridge and his colleague Jackson Briggs (Corporate Development Manager for Draslovka) said Draslovka was most excited about what the technology could offer the base metal space.

Briggs said: “It gives us the opportunity to expand our leadership position in gold leaching agents into base metals. At the same time, it also allows us to incorporate our expertise in that chemistry and chemical manufacturing side of things.”

Stockbridge – not wanting to give away too much – hinted at how this latter opportunity could play out.

“The leaching technology will also influence the way you, for instance, operate, monitor and control the plant,” he said. “This process will be different, and we will be bringing in new technologies to cater to this.”

Considering Draslovka can produce glycine from its existing hydrogen cyanide production footprint, there is potential for a very smooth integration on the supply chain side of things.

Asked to quantify some of the benefits of the technology, Stockbridge was happy to point out GlyLeach’s potential to “simplify the flowsheet” for, say, nickel production, removing the smelting aspect and resultant ore transportation – providing capital and carbon footprint benefits.

Briggs added: “It can change a lot from ore-to-ore with GlyLeach, but, in a really strong business case, you are looking at a 25% reduction in processing costs.”

This is on top of a 10-35% improvement on the recovery side, compared with conventional leaching, Stockbridge said, citing “proof of concept” studies.

As for GlyCat, the sweet spot – as already hinted at – is in gold-copper orebodies where copper is a large cyanide consumer, with the technology allowing cyanide to work more efficiently and effectively.

Both technologies recently featured in OZ Minerals Ingenious Extraction Innovator challenge outcomes publication, while GlyCat has also been the subject of a one-off study looking at combining it with Sixth Wave Innovations’ IXOS® molecular imprinted polymer for gold extraction.

Australia’s Future Battery Industry Cooperative Research Centre, which is sponsored by the likes of Sandfire Resources, Barrick Gold, Coda Minerals (previously Gindalbie Metals) and Poseidon Nickel, is also coordinating some of the work towards commercialising GlyLeach.

There is a strong business case for both technologies first being deployed at scale on tailings deposits that have been deemed to have no associated value – a point both Stockbridge and Briggs acknowledged.

Briggs said: “In terms of accelerating the development of the technologies, there are tailings deposits and waste piles situated all over the globe with high amounts of precious and base metals that have not been extracted due to the limitations and economies associated with current processing technology. We could provide an economic way of extracting those.

“It would also provide us a project with much reduced start-up times compared with, say, a greenfield project.”

Stockbridge added: “We have carried out some work on this type of application before and believe there is the potential to extract 50% of the nickel that they couldn’t access with existing technology by using GlyLeach.”

From the mining company perspective, deploying a new technology on material already written off comes with a lot less risk too.

That is before appreciating that the material won’t have to be smelted on site, that the process produces no free cyanide and that gangue materials do not come out in solution.

It is no wonder the Draslovka duo are excited about the technology’s potential; GlyLeach in particular.

“The ability to help nickel and copper miners produce more metal to rescue some of these deposits that have been forgotten or under-developed because of technology limitations and be able to do so in a way that is more environmentally friendly is exciting.

“Potentially, this technology could help localise more electric vehicle supply chains by removing the need for smelting and providing a cost-effective and environmentally friendly means of extracting metals.

“We cannot wait to get started.”

Hexagon and RCF Jolimont donate blasting tech to Curtin Uni and WASM

Hexagon and RCF Jolimont have teamed up to provide 1,920 Blast Movement Monitors, a GP5300 Detector Kit, HxGN MineMeasure sensor software and training, valued at A$1 million ($712,570), to Curtin University and the WA School of Mines.

Recently launched by Hexagon at MINExpo in Las Vegas, MineMeasure (pictured) allows mines to safely and accurately track blasts to minimise loss and dilution with blast movement sensor software. Measuring 3D blast movement and translating ore polygons with Blast Movement Monitors and GP5300 Detector Kit to account for displacement are, meanwhile, critical steps in achieving optimal ore yield, RCF Jolimont said.

“This is great news for mining students at WASM,” Rob Daw, Chief Technology Officer, Hexagon’s Mining division, said. “MineMeasure is the only portfolio of its type and generates significant profits for customers in every blast at over 120 open-pit mines globally.”

The ability to accurately track blast movement is a huge benefit for mines striving to be smarter and more sustainable. Blasting is a highly variable process and ore loss during blasting can cost mines millions of dollars in lost revenue per year. MineMeasure provides customers with accurate blast information that is used to recover all of a mine’s resources, allowing the valuable ore to be sent to the mill, avoiding dilution and misclassification, according to Hexagon.

Sabina Shugg, Director – Curtin Kalgoorlie Campus, said: “We are delighted with this donation from Hexagon and RCF Jolimont. It enables us to provide our students with training in this best practice blast measurement solution.”

Lex McArthur, from RCF Jolimont, said: “WASM is a recognised global leader in mining engineering studies and we are delighted to have provided part of the funding to enable this donation to come together.”

CSIRO unveils Geoscience Drill Core Research Laboratory in Perth

Australia’s national science agency, CSIRO, has unveiled its latest state-of-the-art research facility, the Geoscience Drill Core Research Laboratory, at the Advanced Resources Research Centre in Perth, Australia.

The only facility of its kind in Australia, the A$7 million ($5.2 million) lab brings together a suite of advanced mineral characterisation equipment, including CSIRO’s unique Maia Mapper, specialised for drill core analysis and research.

Acting Director of CSIRO Mineral Resources, Dr Rob Hough, says the lab’s combination of advanced mining, equipment, technology and services instrumentation alongside CSIRO’s existing advanced characterisation facilities, gives researchers and industry the opportunity to study drill core samples at multiple scales.

“Exploration and mining companies commit large investment in drill core operations to be able to peer beneath the surface to understand orebodies and uncover new underground resources,” Dr Hough said.

“This unique facility is able to maximise data from drill core samples, enabling characterisation across scales; from big picture analyses on kilometres of drill core through to the elemental composition of rock on a microscale.”

Extracting more data from drill core analyses will help unlock Australian critical minerals by providing information that drives key decisions for the discovery, mining and processing of resources, CSIRO said.

“This facility will give researchers and their industry partners the tools to discover and recover the quality resources required for Australia to sustainably support a global energy transition,” Dr Hough said.

CSIRO’s Geoscience Drill Core Research Laboratory is a test bed platform that provides the infrastructure for the research community to work with industry to develop new workflows to enhance success and productivity in mineral exploration and mining, working in collaborative projects with industry.

CEO of the Minerals Research Institute of Western Australia, Nicole Roocke, said the laboratory will support industry and researchers working together to develop a better understanding of Australia’s mineral endowment.

“Faster analysis of drill core by a range of cutting-edge techniques in this facility will speed up the development and testing of new ideas about how mineral systems develop, and help our leading researchers identify new clues to recognising undiscovered orebodies,” Roocke said.

The facility will also provide a new training ground for students, supporting development of the next generation of geoscientists to become innovators for the resources sector.

The Geoscience Drill Core Research Laboratory and Maia Mapper were funded by CSIRO and the Science and Industry Endowment Fund, with co-investment from the University of Western Australia and Curtin University.

Curtin Uni to tap new acoustic sensing tech for Australian resource extraction

A Curtin University research team will work to bring leading broadband fibre optic acoustic sensing technology to the Australian mining, oil and gas and environmental monitoring industries, offering, the university says, a more cost-effective and safer resource extraction process.

As part of the Australian Government’s Global Innovation Linkages Program, the team – led by Professor Roman Pevzner from Curtin’s WA School of Mines: Minerals, Energy and Chemical Engineering – will partner with international collaborators to test the viability of the technology in the Australian landscape.

The project will seek to produce a suite of passive and active geophysical data acquisition and analysis techniques based on broadband fibre optic sensing that aim to significantly reduce the cost of geophysical characterisation of the subsurface and develop a safer resource extraction process, it said.

Curtin University Deputy Vice-Chancellor Research Professor, Chris Moran, said the Curtin research project sought to ensure Australia was not left behind by the latest global advances in fibre optic acoustic sensing technology.

“Despite Australia’s leading role in the deployment and application of fibre optic sensing for research, the current uptake of this technology in the Australian industry lags behind world leaders such as the USA and the UK,” Professor Moran said.

“Demonstrating the benefits of fibre optic technology in Australian conditions in cooperation with our major oil and gas producers will help accelerate the uptake of this technology in the sector, as well as the wider mining and environmental monitoring industries.”

Professor Pevzner said the project would develop technologies that use ambient seismic energy and physical phenomena, including remote earthquakes, ocean microseisms and human activity, through laboratory and field studies.

“Our Curtin team has developed, patented and commercialised a forced-oscillation stress-strain method and equipment for measuring different properties of rocks at seismic and sub-seismic frequencies,” Professor Pevzner said.

“As part of this new project, we will integrate fibre optic sensing technology into our apparatus with the ultimate aim of delivering cost-saving and safer resource extraction processes to Australia’s critically important resources sector.”

As part of the project, Curtin will work with CSIRO, Santos, Woodside and global leaders in seismology and fibre optic sensing in the application to geosciences such as Lawrence Berkley National Laboratory, Iowa State University, Class VI Solutions and Silixa Ltd.

New Kalgoorlie metals research lab to pave the way for mining’s greener future

Curtin University is to open a new research lab geared towards carbon-neutral metal production paths at its Kalgoorlie campus in Western Australia.

Curtin’s WA School of Mines: Minerals, Energy and Chemical Engineering Head of School, Professor Michael Hitch, said the Kalgoorlie Metals Research Laboratory would explore cleaner alternatives through teaching and research that would pave the way for a greener future for the industry.

“The Kalgoorlie Metals Research Laboratory will provide undergraduate students with practical education in carbon-neutral metal production paths, which is particularly important given they are the generation that will help decarbonise the mining industry in the most challenging area of pyrometallurgy,” Professor Hitch said.

Iron ore processing expert, Dr John Clout, has been appointed the Professor of Practice in Pyrometallurgy at the lab with Curtin’s WA School of Mines Kalgoorlie Director, Sabina Shugg, saying he would oversee a high-tech laboratory, fitted with experimental high temperature furnace equipment, capable of simulating the complete industrial process to test renewable energy and green hydrogen sources in the metal extraction process of pyrometallurgy, which currently require fossil fuels.

“Highly respected in the field of pyrometallurgy, Professor Clout will bring real-world experience to the laboratory’s teaching and research, ensuring we contribute to a sustainable future for the Western Australia resources industry,” Shugg said.

Professor Clout said he was thrilled to support the new research hub’s development as an internationally-recognised laboratory and pilot-scale pyrometallurgical research facility for undergraduate teaching and applied research.

“The Kalgoorlie Metals Research Laboratory will aim to develop end-to-end production paths that set new standards for efficiency, value and carbon neutral management, which will ultimately support a cleaner future,” he said.

“After working in the gold, iron ore and nickel industries for more than four decades, I am especially excited to be working with the future leaders of the resources sector to find the most efficient renewable energy sources and processes for pyrometallurgy.

“There is significant potential for industry to be extracting and producing critical metals right here in Western Australia, especially in the Goldfields where there is significant scope for renewal energy production, untapped critical mineral resources, an existing infrastructure network and workforce.”

The Kalgoorlie Metals Research Laboratory has been established as the result of a A$600,000 ($443,697) grant from Curtin University.

The new research facility is also seeking support from industry and private donors for the purchase of additional equipment and ongoing industry-funded projects.

Fortescue backs Pilbara mine site rehabilitation CRC project

The Cooperative Research Centre for Transformations in Mining Economies (CRC TiME), along with partners Fortescue Metals Group (Fortescue), University of Western Australia (UWA) and Curtin University (Curtin), have announced a new project focusing on increasing plant nutrients in iron ore waste, enabling improved mine site rehabilitation in the Pilbara of Western Australia.

The 12-month project is centred around the Fortescue’s Chichester Hub mine site and includes experimental glasshouse-based and laboratory testing undertaken at UWA, along with microbiology expertise from Curtin.

“The Pilbara region has a very thin layer of top soil which is essential for plant growth and is disrupted through mining,” CRC TiME said. “This project will formulate a process to increase plant available nutrient levels, specifically nitrogen for this study, in mineral waste (waste rock and tailings) and stockpiled soils (subsoils and topsoil) using novel plant-microbe systems, to improve the rehabilitation post-mining.”

Kirsty Beckett, Principal of Mine Closure at Fortescue, said: “This project is addressing a critical issue for the mining industry as available topsoil is a key limiting factor in the rehabilitation of large tracts of mining affected land. These areas can cover up to half of some of the Fortescue’s mine sites.”

CRC TiME CEO, Dr Guy Boggs, added: “Post-mining landscapes require the establishment of self-sustaining ecosystems over heavily altered landscapes constructed from mineral waste. Effectively and efficiently converting these landscapes into self-sustaining ecosystems delivers both environmental and financial benefits and provides more certainty on ecosystem resilience.”

CRC TiME receives grant funding from the Australian Government through the Cooperative Research Centre Program.

Gekko installs OLGA, Carbon Scout solutions at Gruyere as part of collaborative project

Gekko Systems, as part of a collaborative project to collect and analyse real-time gold reconciliations and automate gold processing plants, has installed its OLGA and Carbon Scout solutions at the Gruyere gold mine in Western Australia.

In October 2020, METS Ignited Industry Growth Centre announced the consortium of Gold Fields, Orway IQ, CSIRO, Curtin University and Gekko Systems as recipients of the Tranche 4 Collaborative Project Funds. The METS Ignited funding will assist the development of this project.

In a world-first, the project draws together a range of technologies, including the Gekko OLGA and Carbon Scout, and skill sets that are the first step to truly understanding what is happening in a gold production plant in real time and will eventually lead to a fully autonomous gold plant, Gekko said.

Gekko recently installed the OLGA and Carbon Scout at Gruyere (a joint venture between Gold Fields and Gold Road Resources), the site where the project will become reality.

“The Gekko OLGA and Carbon Scout will revolutionise the industry’s ability to measure gold circuit inventory and recovery in real time, move it into the digital world and provide opportunity for full automation,” Gekko said.

OLGA is a world first on-stream analyser designed to continuously read low grade gold grades in slurries and solutions, giving operations the ability to see and control their plants in real time, the company says. The alternative traditional sampling methods involve significant delays – of up to one or two days for feedback.

The Carbon Scout is a self-contained, ground-level sampling system to improve carbon concentration measurements in carbon-in-leach and carbon-in-pulp circuits to an accuracy of ±0.5 grams of carbon per litre of pulp. Uniquely, multiple other data points include slurry density, pH, DO and gold loading on carbon, Gekko explained. Data profiles are provided in every tank, every hour.

“The combination of OLGA and Carbon Scout, supported by the Gekko Sample Delivery System, means all CIL/CIP sampling can be done conveniently and safely at ground level,” it said. “Each tank is sampled by a patented pumpless delivery system. All samples in the plant including leach feed and tails will be delivered through this system to potentially alleviate the need for expensive cross-cut samples.”

The team of Orway IQ will deliver the data through the Trinity program. With the MillROC data system and the Gekko technical team using the data for system analytics.

The ultimate aim of the project is to have gold process and recovery data being analysed within minutes rather than days from anywhere in the world and for production to be adapted to reflect this data, Gekko said.

Curtin University ups glycine gold leaching rates with permanganate agent

Curtin University researchers say they have improved their award-winning glycine leaching technology by “significantly enhancing” the leaching rates for gold ore by using a low concentration of a strong oxidising agent known as potassium permanganate.

The Curtin team is currently working with minerals industry partner, Mining and Process Solutions Pty Ltd (MPS), to commercialise the new process.

The research, published in Hydrometallurgy and led by Professor Jacques Eksteen and Dr Elsayed Oraby both from the Western Australia School of Mines: Minerals, Energy and Chemical Engineering, found that adding potassium permanganate to the process could solve the problems currently associated with leaching gold with glycine (in the absence of cyanide), such as the need for higher temperatures, glycine concentrations and oxygen addition levels.

Professor Eksteen said the research team evaluated various oxidants for their new alkaline glycine gold leach system, with the most successful results observed with potassium permanganate.

“Traditionally, leaching or separating gold and other precious metals from an ore deposit or e-waste materials requires the use of cyanide – a highly toxic chemical compound that is known to have detrimental effects to the environment and to the human body,” Professor Eksteen said. “Industrially, it is very expensive to detoxify cyanide, but it still does not eliminate the risks associated with transporting, handling and processing the chemical.”

Professor Eksteen said glycine is naturally produced by the human body and is essential for life, while cyanide, on the other hand, is dangerous.

“Permanganate and glycine partially decompose to form insoluble manganese dioxide, insoluble calcium oxalate, and nitrogen all of which are naturally occurring, low-toxicity chemical compounds,” Professor Eksteen said. “Whereas cyanide retains its toxicity, even in the waste solution of the extraction process.”

With low concentrations of potassium permanganate being added to the alkaline glycine system, the researchers were able to leach 85.1% of gold from the ore deposit (similar to the extraction by cyanidation) at ambient temperature and using a substance known as a benign reagent, according to Professor Eksteen. This is “quite an achievement” compared with the industry standard, he said.

Dr Oraby said the new process builds on Curtin University’s important work in this space, which has been ongoing for the past eight years.

“Researchers at Curtin University have spent years developing a new leaching process and our work broadens the use of this patented technology, making it more suitable for extracting gold deposits,” Dr Oraby said. “We believe this new process will bring many benefits to gold extraction industries, which, from an environmental point of view, is a much friendlier extraction method.”

The full paper from Hydrometallurgy is titled: ‘Gold leaching from oxide ores in alkaline glycine solutions in the presence of permanganate’.