Tag Archives: GlyCat

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.”

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.

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.