Like going to the dentist, mineral exploration and discovery can involve a lot of drilling and a fair amount of (financial) pain. And much like your friendly neighbourhood dentist, the longer it takes to understand what’s happening, the more it costs.
When it comes to getting information about the minerals and chemistry of a single drill hole, the process can take up to three months. This is because a typical setup involves: setting up the drill site, drilling, extracting rock cores, sampling and logging those cores and sending the samples to a laboratory (which is often a considerable distance from the exploration site) for analysis. Then there is the process of entering and analysing the data, popping the findings into a database and getting it back to the company, so they can make a decision – it’s more complex than a root canal and much more expensive.
To speed up the process of understanding the mineralogy and geochemistry of drill hole cuttings we developed a portable lab, one that can be fitted to the exploration drill rig and analyse in real-time.
Instead of taking three months this process now takes about one hour – that’s more than 2000 times quicker than the current arrangement.
We’ve called this technology Lab-at-Rig®. Developed in partnership with Imdex and Olympus Scientific Solutions Americas, this onsite lab can be fitted to a diamond drill rig and a solid recovery unit to drastically speed-up the process of analysing an exploration site.
The lab includes a sample preparation unit that collects solids from drill cuttings and dries them; X-ray fluorescence and X-ray diffraction sensors to provide chemistry and mineralogy of the sample respectively; and the capability to upload that data to the cloud for analysis, in less time than it takes to watch a movie.
The project came about back in 2011, when a group of researchers were watching a diamond drilling operation near Adelaide and asked a simple question: ‘what if we could analyse the cuttings separated from that fluid in real time?’ We now know the answer: we can save a lot of time and money.
And now, after two years of research and development we’ve just announced that we will be commercialising Lab-at-Rig® and bringing this technology to the world, with the help of our commercialisation partner REFLEX.
With the prototype becoming a reality, perhaps we should turn our attention to making dentist visits quicker.
The Lab-at-Rig prototype was developed under the Deep Exploration Technologies Cooperative Research Centre (DET CRC).
CSIRO, Imdex, Olympus, University of Adelaide and Curtin University are now working on the $11m collaborative DET CRC Lab-at-Rig Futures Project, which will build the next generation system to cover: new sensor technologies, improved data analysis and processing for decision making, and development of the system for new applications and drilling platforms.
By Roger Nicoll
‘Eureka!’ cried the Ancient Greek scholar Archimedes as he (allegedly) ran naked through the streets of Syracuse. He’d just discovered a method to prove the purity of gold by measuring its density, and was decidedly proud of his finding.
Thankfully, these days we favour blog posts to running naked through the streets when we make important new discoveries… but it doesn’t mean we can’t still give a good shout:
‘Eureka! We’ve found a way to produce cyanide-free gold!’
We’ve been working with an American company, Barrick, at their Goldstrike plant in Nevada, to produce the first ever gold bar that doesn’t involve the use of cyanide extraction. Cyanide is, of course, highly toxic and a potential environmental hazard. The new process we’re so excited about uses a chemical called thioshulphate, which will greatly reduce the environmental risks and costs associated with gold production.
Thiosulphate has long been seen as a potential alternative to cyanide for liberating gold from ores, but it has proved difficult to master – until now. Thanks to the new process, which incorporates patented technology we’ve developed with Barrick, the company will be able to process and profit from four million tonnes of stockpiled ore that was uneconomic to process by traditional methods.
As part of the thiosulphate process at Goldstrike, gold-bearing ore is heated in large pressure chambers, or autoclaves. It’s then pumped as a thick slurry of ore, air, water and limestone into the new ‘resin-in-leach’ circuit that takes place inside large stainless steel tanks.
Within the tanks, the slurry interacts with thiosulphate and a fine, bead-like substance called resin that collects the gold. At full capacity, 13,400 tons of ore can be processed daily, with leaching taking place simultaneously in two sets of seven tanks.
Our very own minerals expert Danielle Hewitt had a hands-on role in developing and proving the CSIRO technology incorporated at the Goldstrike plant. But for security reasons, it was strictly hands-off the resulting gold bar.
“This was a golden moment more than 20 years in the making, including three years working with Barrick to refine the commercial process,” said Danielle.
She said the new process will contribute an average of 350 to 450 thousand extra ounces of gold each year to the operation, allowing the large plant to keep operating.
The new technology could also have some benefits closer to home, with the potential to safely recover gold in Australia where cyanide would otherwise pose a significant environmental risk and environmental protection cost.
As with Archimedes, another gold standard solution.
By Emily Lehmann
Being recognised as one of Australia’s ‘foremost visionaries’ for your work is, understandably, a pretty big deal.
But when you’re the brains behind an exploration tool that’s utilising superconducting quantum interference devices (or SQUIDs, for short) to locate more than $10 billion worth of mineral ore discoveries across the globe, it might help explain a few things.
This was the case last week for two of our very own researchers – Manufacturing Flagship deputy director, Cathy Foley and research scientist Keith Leslie – were awarded the prestigious Clunies Ross Award for innovation and commercialisation, thanks to their LANDTEM exploration tool.
This was a particularly momentous occassion for Cathy, who became only the fifth woman to win the award since its inception in 1991.
LANDTEM is a portable exploration tool that’s valuable for detecting highly conductive ores like nickel sulphides, gold and silver. LANDTEM uses the SQUIDs technology to differentiate the target ore from other conductive material or overburden, even for deeply buried ores.
It’s a far less invasive and more targeted technology then, say, drilling, so it’s more environmentally friendly. It’s also incredibly efficient: one company in Canada cut its exploration costs by 30 per cent using LANDTEM.
So, why do we care? Because valuable minerals are found almost everywhere, and they are essential to our life as we know it today. To put it in context, every smartphone contains about 40 different minerals; the average medium-sized car contains 19 kilograms of copper amongst a heap of other metal; and rare earths are needed for green energy products such as solar panels and wind turbines.
Minerals are also an important contributor to our national economy, and are our most valuable export business, worth about $119 billion.
While we have a wealth of mineral resources, these are finite and most of our deposits near the surface have already been discovered. That’s why we’re developing new efficient tools like LANDTEM to help explorers make valuable mineral discoveries needed for the future.
Cathy and Keith are continuing their valuable work by significantly enhancing the sensitivity and functionality of LANDTEM. Most recently they developed a new and improved version that will be able to detect ore bodies even deeper underground.
Watch this video for a closer look at the development of LANDTEM:
Keep digging over at our Mineral Resources Flagship to learn about similar projects.
It’s no secret that mining is important to Australia, but that doesn’t necessarily make it popular with society at large.
We wanted to have a better understanding of what Australians think about mining, so in 2013/14 we conducted an online survey of 5,121 Australians.
The survey results have now been published as Australian attitudes toward mining: Citizen Survey – 2014 Results
Surveying community attitudes helps us to understand the impacts and benefits of mining, and how the relationship between the mining industry, government and society affects what Australia’s citizens think about it, and how much they accept the mining industry. It gives us insight into what needs to happen before mining has a ‘social licence to operate’ in Australia.
We’ve gone beyond basic descriptions of attitudes towards the extractive industries, and looked at the relationship between mining and society in a more constructive and sophisticated way.
We wanted to know what goes into influencing trust in the mining industries, and the government, over mining developments. What, for example, is the relationship between good governance and social acceptance of the extractive industries? What are the key issues for a productive dialogue between the extractive industries and other stakeholders?
Some of the important findings from the survey are that:
- People view mining as central and significant to Australia’s economy and standard of living. They see it as a ‘necessary’ industry for Australia, which is important to Australia’s future prosperity
- Australians generally understand what it means to have a significant mining industry. Overall, they think that at present the benefits of mining outweigh its impacts.
- The more the benefits of mining outweigh the costs, the higher the level of acceptance. If this balance is perceived to move toward the negative impacts of mining, acceptance of mining will be eroded.
- Australians trust and accept the industry more when they believe the industry is listening to them and will respond to their concerns, when benefits from mining are shared equitably, and when the legislative and regulatory frameworks in place make them confident that industry will do the right thing.
- Governments and industry need to work with communities to earn and maintain the ‘social licence to operate’ and develop effective, constructive, mutually beneficial relationships.
By David R Mole
Volcanic eruptions are as old as the planet itself. They inspire awe, curiosity and fear and demonstrate the dynamic internal activity of the Earth. However, the impact of modern volcanoes pales in comparison to those that graced our planet millions (even billions) of years ago.
These include “supervolcanoes”, volcanic eruptions a thousand times more powerful than the 1980 eruption of Mt St Helens; and large igneous provinces (LIPs), which consist of rapid outpourings of more than one million cubic kilometres of basaltic lava, such as the Siberian Traps in Russia.
In a paper published this week in the Proceedings of the National Academy of Sciences, my colleagues and I set out to find how the hottest and rarest type of volcanoes – the ancient komatiites – were formed.
Knowing how and why komatiites are concentrated in specific belts could help discover new ore deposits, potentially worth billions of dollars.
Komatiite lava flows date back around 1.8 to 3.4 billion years and formed when Earth’s mantle (the layer between the crust and the outer core) was much hotter.
They erupted at temperatures exceeding 1,600C and produced hose-like fire fountains and lava flows that travelled at more than 40km/h as bluish-white, turbulent lava rivers.
These crystallised to form some of the world’s most spectacular igneous rocks – as well as a number of giant nickel deposits, found mainly in Western Australia and Canada.
Komatiites have been studied for more than 60 years and are fundamental in developing our knowledge of the thermal and chemical evolution of the planet, but until recently we didn’t understand why they formed where they did.
So how are komatiites formed?
Komatiites are found in ancient pieces of crust, or cratons, preserved from the Archean Eon (2.5 to 3.8 billion years ago). These cratons contain greenstone belts – preserved belts of volcanic and sedimentary material that often contain deposits of precious metals.
Many cratons exist worldwide. One of the largest is Western Australia’s Yilgarn Craton, which hosts most of the gold and nickel mined in Australia. This craton has only a few specific belts that contain major komatiite flows.
Previous research shows that komatiites were formed from mantle plumes – upwelling pipes of hot material that stretch from the outer core to the base of the crust.
Around 2.7 billion years ago in a huge global event referred to as a “mantle turnover”, multiple mantle plumes formed, and one hit the base of the early Australian continent – the Yilgarn Craton, forming some of the hottest lavas ever erupted on Earth.
When plumes first hit the base of the lithosphere – the 50-250km-thick rigid outer shell of the Earth – they spread out into discs of hot material more than 1,000km in diameter.
Today there is evidence of this in places such as the huge Deccan basalts that cover much of India.
Despite this spread, komatiite belts are sparse and only found in certain areas. One of our research goals was to find out why.
Mapping the early Australian continent
We used specific isotopes of the element hafnium to determine the age of the crust that formed the granites (the material which makes up the cratons) and if it had a mantle or a crustal source.
Mapping out the isotopic compositions of the granites revealed a jigsaw pattern in the crust, and regions where the granites formed by melting pre-existing, much older crustal rocks.
It also showed younger areas where the crust was newly created from sources in the deeper mantle.
By collecting samples of Archean granites from all over the Yilgarn Craton, we were able to map the changing shape of the Archean continent through time.
When we compared the nature and shape of the continent with the location of the major komatiite events, we found a remarkable correlation. The maps showed that the major komatiite belts and their ore deposits were located at the edge of the older continental regions.
This is due to the shape at the base of the ancient Australian continent. As the plume rises, it impacts the older, thick lithosphere first.
As a result the plume cannot generate much magma so it flows upwards along the base of the lithosphere into the shallower, younger areas. Here huge volumes of magma are generated at the boundary between the old, thick and young, thin areas of the lithosphere, so komatiites and their nickel deposits are located at the margins of Earth’s early continents.
Some research questions remain. The origin of the continents imaged in our study and the tectonic system that formed them is still unknown.
What our work shows is that continent growth significantly affects the location, style and type of later volcanism, as well as the location of major ore deposit areas.
We hope that this work will help unravel the volcanic history of other ancient geological terranes, as well as aid in the search for mineral deposits in relatively unexplored cratons such as those in West Africa and central Asia.
This project was funded by Australian Research Council (ARC) Linkage Grants LP0776780 and LP100100647 with BHP Billiton Nickel West, Norilsk Nickel, St Barbara, and the Geological Survey of Western Australia (GSWA). The Lu-Hf analytical data were obtained using instrumentation funded by Department of Education Science and Training (DEST) Systemic Infrastructure grants, ARC Linkage Infrastructure, Equipment and Facilities (LIEF), National Collaborative Research Infrastructure Strategy (NCRIS), industry partners, and Macquarie University. The U-Pb zircon geochronology was performed on the sensitive high resolution ion microprobes at the John de Laeter Centre of Mass Spectrometry (Curtin University).
By James Tickner, Office of the Chief Executive Science Leader
Globally, the minerals industry is operating in an increasingly challenging environment. Lower and more volatile metal prices, declining ore grades, increasing production costs, environmental pressures and mounting global competition all affect the sector.
At CSIRO we are working with the minerals industry to develop new technologies that will help maintain global competitiveness – and we recently announced a new X-ray technology to do just this.
It has the potential to boost productivity and save the Australian gold industry hundreds of millions of dollars a year.
The challenges of producing gold
Gold in Australia is normally mined at very low grades – as little as one gram of gold for every tonne of rock. Explorers looking for new gold deposits, and the people running mines or monitoring extraction plants, need a really sensitive detection method.
The industry standard analysis, fire-assay, is complex, laborious and destroys samples by fusing them at temperatures up to 1,200C.
The process is normally carried out in centralised laboratories. This can lead to turn-around times of several days, particularly if materials are sent in from remote locations. Running a large processing plant is like trying to drive a truck looking only in the rear view mirror.
The lack of real-time feedback is one of the factors contributing to a typical gold plant only extracting 65-85% of the gold present in mined rock. And with Australia producing around A$10 billion worth of gold last year, billions of dollars worth of gold is potentially going to waste.
Even a 5% improvement in recovery efficiency would be worth half a billion dollars a year. Huge amounts of water and energy are required to extract gold, so this would also pay dividends in reducing the resources embedded in every ounce of metal.
Our X-ray method
The X-rays force nuclei at the heart of any gold atoms present into an excited state and this results in the gold atoms becoming weakly radioactive for just a few seconds.
A highly sensitive detector picks up the radiation emitted by the gold and reads out the level of the precious metal.
The big benefits of the method are simplicity, speed and accuracy. Up to half a kilogram of material is packed into a plastic jar and fed into the analyser. A few minutes later, the analysis is complete and the sample is returned unchanged.
As the method is completely non-destructive, the sample can be subjected to further testing if required.
Measuring a large mass of material improves accuracy. This is especially true for gold, as distribution can be very patchy even in a rich ore deposit.
One of the great advantages of using nuclear analysis is that it is sensitive to all forms of gold. It doesn’t matter what chemical or physical form the gold takes, or whether the sample is a solid or a liquid. If gold atoms are there, they will be seen and counted.
Proving the new technology
While the science behind using X-rays to find gold has been known for decades, achieving the necessary sensitivity was a major challenge. CSIRO combined the latest developments in high-power X-ray sources and radiation detectors with advanced computer modelling. This led to an analyser capable of detecting gold at levels nearly ten times lower than previous systems.
We have recently completed tests in collaboration with the Canadian technology company Mevex which showed that our prototype analyser is capable of measuring gold two to three times more accurately than commercial laboratory fire-assay. We are now exploring how to bring the technology to market with Australian and international partners.
An X-ray based analysis system would probably be first used in a commercial assay laboratory. But things get really exciting when you think what might be possible beyond that. A complete, fully automated system could be packaged into a couple of shipping containers. This could be trucked out and dropped down for real-time, on-the-spot analysis in remote locations.
Some of the prospects for the technology include speeding up the exploration for gold and three-dimensional mapping of deposits by monitoring the spoil produced as bore-holes are being drilled. Helping to control the billion-dollar concentrator plants used to process gold ore would be another important application.
Any new technology is a jigsaw puzzle built around what starts out as just a crazy idea. The most satisfying part of working as an applied scientist is nurturing some of those ideas into the real world.
Rapid X-ray analysis is set to make a huge difference to the productivity and competitiveness of the gold industry.
To search for gold back in Ye Olde days, you’d have to pick up your pan and start sifting. Thankfully, we’ve now got a suite of fancy tools to help us find minerals deep underground.
It might sound like science fiction, but we’re using super-charged metal detectors that beam electromagnetic pulses from the sky. We’ve even got satellites in space helping us search for new deposits.
But it’s not all high tech – nature is still giving us plenty of clues. When it comes to gold, termites, ants and even leaves point us in the right direction.
For more fun facts on exploration check out this infographic – the final in our rockin’ series on Australian minerals.
Find out more about CSIRO’s minerals research.