Insights from ALTA ISR 2020

What next for in-situ recovery?

In-situ recovery (ISR) technology has progressed significantly over recent years with increased interest in the technology in the mining industry.

Advanced understanding is being achieved in various areas (environmental and social aspects, modelling, economics, monitoring, permeability) to facilitate the implementation of ISR.

The annual ALTA ISR Conference, an event co-organised by ALTA and CSIRO, provides a leading opportunity for those interested in ISR to convene and learn about recent developments and network with others in the field.

This year’s event, held on 19 November, was hosted online for the first time.

Despite restrictions, 16 industry experts presented on topics from the running and economics of ISR operations to navigating legislative, social, technical, and environmental factors.

One attendee, co-organiser, presenter and panel chair was my colleague Dr Laura Kuhar.

Here, she will share details of some of the most relevant presentations, and discuss the three key insights that stood out to her throughout the conference.

She covers both the growing possibilities and continuing challenges the mining industry faces in widespread adoption of ISR technology.

1. There are a number of benefits and possibilities for those willing to explore ISR

Companies are looking for mining technologies that are alternatives to conventional open pit and underground mines.

ISR could provide them with an opportunity to process stranded assets and recover residual value in existing deposits, which may not be possible to achieve using conventional approaches.

For example, the Kapunda copper deposit in South Australia, which is located 500m from the nearest road is unlikely to be able to be processed by conventional open pit/underground technologies.

ISR may have the ability to help mine in situations where:

• a small environmental footprint is required
• deposits contain low-grade ore
• deposits are in inaccessible, protected or remote areas with limited infrastructure or there is competition for land usage
• it is unsafe for people to interact “at the rock face”.

In future, it is also hoped that ISR could be used to process deposits that:

• deep
• contain hard rock
• are increasingly complex.

Furthermore, conventional technology and processes may result in capital and operating costs being too high for the processing of new deposits and the generation of unacceptable amounts of waste and tailings.

When there is no other way to mine a deposit or to potentially derive a greater economic benefit, ISR could deliver a low-impact, scalable, low opex process with a healthy margin.

This was highlighted by Ewan Sellers (CSIRO/Mining3) who presented on the value case for in-situ mining and Mario Rossien (Evolution Mining) who presented a strong economic case on the potential for modified ISR application in hard rock deposits.

The technology could also provide an opportunity to small mining companies.

Small companies are looking for opportunities (in terms of cost and scale) that are accessible to them.

ALTA keynote speaker Leon Faulkner (EnviroCopper) commented that –

“Geoscience Australia estimates significant ‘paramarginal’ ore in Australia (e.g., > 1 Mt Cu, > 150 tonnes of Au, which equates to ~$20Billion – some of which is very likely amenable to ISR).”

“In South Australia specifically, there are more than 900 known Cu occurrences and more than 100 contain copper oxide species in rock that may be suitable for ISR”.

Some of these deposits are not of interest to large mining companies but could be favourable for small mining companies to process.

The challenge here is that we do not have all the technical components in place to apply ISR to all mine situations.

A number of the presentations at ALTA reflected these technical challenges and the research surrounding them, including:

• Creating access, via directional drilling, hydraulic fracturing and blasting (Saeed Salimzadeh, CSIRO and Peter Dare-Bryan, Orica)
• Permeability enhancement (Erika Myers, Umwelt- und Ingenieurtechnik GmbH Dresden)
• Creating access using liquid nitrogen (Hamed Akhondzadeh, Edith Cowan University)
• Understanding coarse particle leaching (Laura Kuhar, CSIRO).

 

2. There are trial sites making progress

Alan Taylor (ALTA Metallurgical Services) spoke about the ISR of copper ‘coming of age’ with implementation of two demonstration copper operations in Arizona, USA.

The most advanced operation in the region is the Florence Copper project, which is running a production test facility of four injection, nine recovery and fifteen monitoring wells.

The wellfield operation commenced in January 2019 and copper cathode was produced a few months later in April 2019.

The second high-profile project is the Excelsior Gunnison project, which commenced mining operations in January 2020, with 41 injection and recovery wells.

A wellfield optimization program was undertaken at site to deal with issues such as blockages by copper precipitation and operation was limited due to COVID-19.

As of November 2020, the solvent extraction–electrowinning production facility had been commissioned with copper cathode production expected shortly.

Interestingly, at ALTA, Drummond “Dusty” Earley spoke of valuable research by the US Bureau of Mines at the Santa Cruz copper project in Arizona prior to the Bureau’s closure in 1996.

Much of this research is not widely accessible because of the limited electronic/internet access available at that time.

Closer to home, EnviroCopper is investigating the potential for processing the Kapunda deposit in South Australia by ISR.

They have been able to mostly overcome initial technical challenges, and have made a significant effort to mitigate social risks by engaging early and often with stakeholders and local communities, and providing easy and interactive ways for locals to voice concerns and follow the impact of project work.

And also located in South Australia is Heathgate’s Beverley uranium operation, which commenced production in late 2000.

 

3. There are environmental, social and legislative challenges that need to be overcome

While there is global increasing interest in ISR technology for the processing of other commodities – and industry is cautiously excited about ISR potential – there are a number of social, environmental and legislative challenges that need to be overcome.

Environmental:

Despite the potential large environmental benefits ISR delivers (reduced energy usage; possibility for multiple land usage, such as mining followed by farming; reduced noise, dust; elimination of tailings and other waste), there are concerns, particularly from the public, about solution containment.

One of the areas that requires attention is stakeholders being dubious of the technology, because it involves solution injection underground, and concerns related to groundwater contamination.

While research continues into the possible impacts of underground injection, for example via hydrogeological modelling and fracture mapping studies, Simon Apte (CSIRO) presented on the impacts of hydraulic fracturing on surrounding groundwater near coal seam gas sites in Queensland.

While not specifically an ISR project, the results showed no impact of coal seam gas operations on water quality, which is promising.

Furthermore, Mostafa Sharifzadeh (Western Australian School of Mines) presented on understanding flow through fractured rock masses, which is of vital importance for ISR projects.

Social:

The industry realises that social aspects are potential challenges to wider ISR uptake. For the ISR demonstration sites in Arizona (for copper) and South Australia (for uranium) social engagement has been vital to ensure project progression.

Tom Measham (CSIRO) spoke about the community perceptions of ‘new’ copper mining using results from a study at the potential Kapunda Copper ISR project. He identified four factors of social understanding that need to be met:

• understanding procedural fairness (people have a voice and their concerns are considered)
• distributional fairness (benefits and impacts are spread evenly)
• confidence in governance (people are confident that appropriate checks and balances are in place)
• trust (companies are transparent and act responsibly).

There has been a significant effort by EnviroCopper to engage with the local communities to gauge their concerns and direct research to address these.

Legislative:

Despite their positive expectations, EnviroCopper’s Leon Faulkner spoke on legislative challenges they are facing at Kapunda that will likely arise for other small mining companies as well:

• the existing regulatory framework in South Australia focuses on uranium ISR, and requires adaptation for non-uranium ISR projects. This has made controlling cost and time difficult during early stages of project development, while managing environmental and social risks
• the challenges of overlapping land access jurisdictions
• resource estimation is complex, the technology is new and unfamiliar to investors, and therefore it is more challenging to earn investor confidence.

Doris Hiam-Galvez (Hatch) discussed how the US and South Australia have the most mature permitting regime because of the presence of ISR projects in these regions.

Industry and research partnerships will make ISR widely viable

ISR technology isn’t new – it has existed for uranium processing for more than 50 years, with approximately 50% of global uranium currently recovered by ISR.

However, despite the extensive use of the technology for uranium processing, more general awareness of ISR technology does not exist in the mining industry.

With further knowledge, tools and frameworks to understand the steps to implementation, ISR could be a more positive and more widely adopted option for the mining industry.

For permeable deposits, the expertise largely already exists for implementation and trials of ISR technology in the field.

For hard rock deposits, more research is being carried out, and there is the opportunity for industry to partner with research projects to test and trial emerging technology.

With six CSIRO presenters at this year’s ALTA ISR event and many more involved in ongoing research and development, CSIRO is a leading expert in ISR.

We continue to conduct research to progress the technical aspects to enable ISR, increase stakeholder confidence and ensure we can conduct ISR safely.

We are keen to work with operations to develop greater understanding of the potential for ISR application at a particular deposit, as well as technical and economic understanding of the approach to ISR processing by:

• characterising ore from deposits of different commodities
• testing a lower impact, targeted suite of lixiviants and determining the potential metal extractions, extraction time frames and which lixiviant(s) may be most suited for the application
• understanding solution containment and simulating fluid flow with reactive transport modelling
• conducting economic modelling/evaluations to determine the financial viability of a process
• assisting with continuous monitoring during ISR operation (e.g., fluid conditions using our Vesi (formerly SENSEI) technology)
• looking at hybrid options (e.g., blasting underground and conducting an ‘inverted’ heap leach in a technique that is termed ‘in-mine recovery’).

As well as to drive social and environmental acceptance by:

• determining baseline environmental conditions and producing a scorecard for continuous assessment of the environmental status during operation
• aiding with earning social acceptance and understanding perceived concerns and opportunities.

More broadly to industry and government, our research increases the potential for unlocking ISR implementation and the opportunities it offers.

We are keen to collaborate and partner with industry and speed up research and abilities, and are able to explore grants and funding for those interested in doing so.

If you’d like further insights and outcomes from the ALTA ISR conference,  registration for access to on-demand conference sessions will remain open until March 2021, and can be accessed through the ALTA conference website.

If you’d like to learn more about implementing ISR technology or undertaking R&D to overcome operating challenges, we are interested in partnering with you to bring value and help your organisation thrive.

Email me, Chris.Vernon@csiro.au, to explore how we can help you.

Subscribe and receive more updates on our mineral processing research.