Eureka! A solid gold solution to make Archimedes proud

We've found a golden solution for gold extraction.

We’ve found a golden solution for environmentally friendly gold extraction.

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.

Danielle Hewitt with the first  gold bar produced using the new process.

Danielle Hewitt with the first gold bar produced using the new process.

“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.

For more about this and other innovations from our Mineral Resources Flagship see the latest issue of Resourceful.


Gifts of the GAB: Five not-so-fishy facts about the Great Australian Bight

Southern right whale at the Head of Bight, South Australia.

Southern right whale at the Head of Bight, South Australia.

Tomorrow is World Ocean Day, the United Nations-recognised day of ocean celebration and action. It’s a day to stop and take stock of the importance of the ocean and its major role in our daily life. Our coastlines and the waters beyond are an intrinsic part of Australian life; not to mention their importance to our climate, biodiversity, and countless industries.

We’re involved in a veritable ocean of research around the sea and skies of Australia, which you can learn more about here. There’s so much that we could talk about, from our world-leading shark research, to our sustainable prawn fisheries in the Timor Sea … but today we’d like to focus on that great expanse of salty water to Australia’s south: the Great Australian Bight. Or, as it’s so affectionately known, the GAB.

IMG_2443It’s an amazing place. Here are just five gifts of the GAB:

  1. The GAB produces 25 per cent of Australia’s seafood (by value), supporting Australia’s largest commercial fishery (by volume).
  2.  More than 85 per cent of known species of fish, molluscs and echinoderms in the waters off Australia’s southern coast are found nowhere else in the entire world
  3. The region contains great white sharks and iconic marine mammals such as whales, seals, dolphins and seabirds, and is home to more than 80 per cent of Australian sea lions.
  4. The GAB’s physical characteristics make it globally unique and quite distinct from the adjacent seas east and west of Australia.
  5. A 4-year, $20 million Great Australian Bight Research Program is one of the largest whole-of-ecosystem studies ever undertaken in Australia. Specimens will be collected from the deepest set of samples ever taken from the area, to a depth of 3 kilometres. Did you know we recently deployed 125 archival tags into juvenile southern bluefin tuna in the Great Australian Bight to understand the movement and behaviour of these fish in what is their most significant feeding ground in the world. If you find a fish tag, please let us know. You can find more info here.

We’re also working with BP, the South Australian Research and Development Institute (SARDI), the University of Adelaide, and Flinders University to improve understanding of the Great Australian Bight. Our collaborative research will ensure future development in the region is ecologically sustainable. Find out more here.


A new Atlantis

Not this one. It's the Atlantis Hotel in the Bahamas.

Not this one. It’s the Atlantis Hotel in the Bahamas.

Wouldn’t it be good if there were a spare ecosystem we could try things out on before making a decision about how we use resources? Sadly, there’s no Earth II, but at least we have Atlantis.

No, not the fabled sunken city, but a marine ecosystem modelling tool that lets resource managers and coastal planners test drive their decisions before they commit to them in the real world.

We’ve developed a model that encompasses oceanography, chemistry and biology, and simulates ecological processes such as consumption, migration, predation and mortality.

The United Nations rated Atlantis as the best ecosystem model in the world for looking at alternative management strategies for fisheries, and regional versions are being used in management strategy evaluation for more than 30 ecosystems in a wide range of places.

Before models like Atlantis were available, decisions about resource use were made in isolation. We’d make our plans about things like fisheries or water quality based on what we knew about fisheries or water quality, rather than on their effects on the entire system. And decisions like these – that don’t look at the system as a whole, interdependent web – can often be on the wrong side of the law of unintended consequences.

So Beth Fulton got to work and created Atlantis.

It gathers information including ocean currents, and the way the food system works, all the way up from phytoplankton – tiny plants that exist in oceans and underpin the marine food chain. They build up through to seaweed and sea grasses, different kinds of fish, to marine mammals like dugongs, sharks and seabirds. The modelling incorporates the ways people interact with the oceans and the Earth, and includes coastal industries such as ports and fisheries, along with the social and economic pressures that drive resource use decisions.

A conceptual diagram of Atlantis

A conceptual diagram of Atlantis

Atlantis has its longest usage history in south-eastern Australia. This is a marine area of about 4 million square kilometres, and home to Australia’s largest fishery. It’s also – literally – a hot spot for ocean warming. There the ocean temperature is rising faster than anywhere else, and the Australian current that extends down the eastern seaboard to Victoria is pushing further south to Tasmania.

The carbon dioxide that’s sucked up into the ocean is making the water more acidic. The balance of marine species, and their range, is likely to alter as the climate warms. We’ll still have fish and still be eating them, but there will need to be some major decisions made about how best to manage fisheries.

One of the beauties of the Atlantis model is that it can be re-calibrated with new data as the effects of warming oceans begin to be felt. This will be vital to making far-reaching decisions that can no longer be based on the old certainties.

For more on our work in oceans, head to our website.


This scanner has a few bugs, and we’re glad about it

How many insect specimens do you think are in the Australian National Insect Collection? A few hundred thousand? A million?

Actually, at the moment, it has about 12 million specimens, and it’s growing by about 100,000 a year. Like many natural history collections around the globe, the ANIC holds thousands of holotypes – each the single specimen of a species that is used to define its characteristic features.

There are all sorts of uses for these specimens, and a lot of people outside the world of entomology have very good reasons for looking at them very closely. But they’re fragile things, and many of them are tiny, so they can’t really leave their cases. And photographs don’t capture all the detail that’s sometimes needed.

So how to make the necessary information available to the people who can use it, while keeping the precious specimens safe and available for research work? Digital 3D colour modelling is ideal, but there have been some major barriers to doing that effectively. The system most used at present – Micro Computed Tomography (Micro CT) can create amazingly accurate models. But it doesn’t capture the object’s natural colour, which is vital information for species identification. It can take many hours. It’s X-ray based, so it needs special safety equipment. The machines also cost around $100,000, and they’re not portable.

Well, there had to be a better way, didn’t there?

So Matt Adcock and his colleagues did some lateral thinking, and came up with InsectScan 3D. This re-imagines 3D image-gathering in a way that doesn’t need custom-made or high-cost equipment (some of it actually came from the local hardware megastore), and the image is in full colour. The entire system uses standard components, and costs less than $8000 for the hardware and software. The digital 3D models come out in a file size small enough to be sent by email and used in web pages. And to make it even better, we can 3D print them.

3D scanned images, printed in 3D. Image by Eleanor Gates-Stuart

3D scanned images, printed in 3D. Image by Eleanor Gates-Stuart

The process uses multiple photographs of the subject, mounted on a disc marked with a pattern of dots. Using a standard DSLR camera and a 2-axis turntable, the insect is photographed at different angles and focus depths. These are then plotted by a computer, using the dot pattern to gauge the angle from which the picture was taken.

In some cases the 3D image is more useful than conventional microscopy. Obviously, the actual specimen provides all the information, but it has to be examined under a microscope for features like the mouth area and hair surface on the head. Out-of-focus effect and other physical restrictions makes using a microscope to view the actual specimen more difficult than viewing the 3D model.

The possibilities for this system are varied. Entomologists and taxonomists already have a massive backlog of insect types which have not yet been digitised in any form, and this system can provide what they’ve been asking for: a network of automated instruments that can clear the backlog by quickly and accurately creating 3D images of type specimens.

Schools and universities can use 3D models of insects as rich education materials, so students can interact with insects without endangering the fragile specimens.

But the most interesting use could be in quarantine and biosecurity. Invasive insects and the diseases they carry are an ever-present threat to Australia‘s environment, its agricultural industries and the health of the population. With this affordable, portable and accurate scanning technology, quarantine officers could carry a 3D gallery of invasive insects with them on inspections to help identify pests. Suspect specimens could be scanned in 3D and sent straight to an expert entomologist for examination. High resolution image libraries will mean we can quickly extract, analyse and share rich information, supporting biodiversity discovery, species identification, quarantine control, and unlocking the value of our biological collections.

Sounds pretty good, doesn’t it? This technology is a finalist in the Smart 100 innovation awards, and there’s a people’s choice category. If you like it as much as we do, we’d really like you to vote for it. All you need to do is click the ‘Share on Facebook’ (or Twitter, or any of the others) button and that’s a vote.


Rotating sea cucumbers is kind of a big deal

Thelenota ananas (the Prickly Redfish)

Thelenota ananas (the Prickly Redfish)

By Chris Gerbing 

The poor old sea cucumber doesn’t fare very well in the oceanic food chain. They’re slow-moving, (cu)cumbersome creatures that are considered a delicacy by us humans… and they even cop the brunt of Nemo’s swim up comedy routine. But they’re also an important source of income for many coastal communities around the world, particularly in the South Pacific. This is why they need to be rotated (but we’ll get to that in a bit).

Sea cucumbers, when processed and dried, are turned into bêche-de-mer, which is considered a delicacy in Chinese culture. Demand for bêche-de-mer has increased markedly in the last few decades.

The ugly cousins of the star fish are part of the benthic family of marine organisms. These bottom dwelling creatures are slow and sluggish and literally cannot move quickly enough to save themselves. That combined with their easy accessibility and high value means that sea cucumber fisheries around the world are easily overfished and many fisheries have collapsed.

In Australia, the Queensland east coast bêche-de-mer fishery is perhaps Queensland’s oldest, with harvesting starting in the mid-nineteenth century and continuing up until the beginning of WWII. A revival of the fishery did not occur until the late 1980s. With this resurgence new management systems were introduced to protect the fishery. Since then various management strategies have been implemented to align with management acts and regulations that influence this fishery.

The modern Australian bêche-de-mer fishery provides to the livelihoods of fishers from coastal communities in northern Queensland. It is typical of many small scale fisheries in Queensland and Australia in that it is difficult to do a detailed stock assessment, and hence there have been few undertaken.

Queensland East Coast Beche-de-mer fishery management zones

Queensland East Coast Beche-de-mer fishery management zones

This is where the rotating sea cucumbers might start to make sense.

Management agencies and industry have attempted to mitigate risk to sea cucumber populations by introducing rotational fishing zones that limit the catch, spread the activity and improve the overall sustainability of the fishery. A management strategy that humans have used on land for centuries, rotational harvesting has been less commonly applied to marine resources.

This strategy has been applied in the Australian east coast fishery and seen the creation of 154 fishing zones that can be fished for single 15 day periods every three years. Essentially, the zones are rotated…but the effectiveness of this strategy needed testing.

Research published this week  by a CSIRO research team has shown that there are clear advantages to a spatial rotation harvest strategy. Using a quantitative modeling approach, the team showed that rotating the harvest zone improves the biological and economic performance of the fishery. They also found that lengthening the rotations out to six years can be helpful too.

The greatest benefit of rotational harvesting was measured for the slowest growing slugs in the sea, and also for the tastiest, who suffer under high fishing intensity.

Holothuria scabra (the sandfish)

Holothuria scabra (the sandfish)

This finding has applications for sea cucumber fisheries across Australian waters, as well as regional fisheries in South Pacific countries and south-east Asia. There are also global applications, particularly in other fisheries like abalone, geoduck clams and sea urchins that can be susceptible to overfishing.

There is potential for expansion of the Australian sea cucumber fishery in terms of both volume and value of products by spreading the fishery effort widely. We cannot say however if this will lead to sea cucumbers appearing on many local menus any time soon. But in the meantime, please keep your sea cucumbers rotating!


Bright Spark saves lives: finding order in the chaos of bushfires

Bushfire

Bushfires such as this one in Western Australia can be hard to predict.

James Hilton, CSIRO; Andrew Sullivan, CSIRO; Mahesh Prakash, CSIRO, and Ryan Fraser, CSIRO

Bushfires are highly chaotic natural events, dangerous to people and homes in their path and even more dangerous to those brave enough to fight them.

Australia is all-too-familiar with tragedy caused by bushfire, with days such as Ash Wednesday and Black Saturday ingrained into public and personal memories. The costs in a bad bushfire season can run into billions of dollars, although nothing can truly account for the lives and communities affected by these events.

Bushfires are hard to predict for two reasons. No-one can be sure where or when they will start, although well-educated guesses can be made.

Weather conditions conducive to the outbreak of bushfires are well known and serve to prompt total fire bans to reduce the chance of accidental ignitions. Unfortunately, some of the most frequent causes – lightning strikes and arson – are inherently unpredictable.

Once a bushfire has started it is also difficult to predict precisely where it will go.

While all bushfires do follow well understood physical laws, fine scale variations in factors such as the weather, topography and distribution of fuel mean that a bushfire may appear to behave erratically.

Sudden shifts in the wind direction may cause a quiescent flank to burst to life, creating a new wider fire front. A single tree next to a road or river may enable the fire to jump across an otherwise impassable barrier.

Fighting and controlling fires is a major difficulty for emergency services due to this level of uncertainty. Even deciding the best evacuation routes in uncertain fire conditions can be challenging.

Studying bushfire behaviour

This apparent unpredictability has not deterred fire scientists. Since the early part of the last century these scientists have been carefully studying the behaviour and spread of fires in different conditions.

The results have been collected and tabulated into mathematical formulae to predict how fast a fire will spread. These have been used in Australia for many years for early warning and planning purposes.

But the speed of a fire depends on a wide range of factors. These range from large scale effects, such as the weather or slope of the land, to the small scale, such as whether the fire is burning through leaf litter or grass. The resulting mathematical calculations are complicated, as all of these factors must be included.

Fire science, like many other science disciplines, has benefited from the recent growth in computer processing and data storage. These advances mean meteorological models can now give weather forecasts at very fine scales.

Improvements in computer algorithms have led to newer, more powerful, models to represent spreading fires. Growth in data storage has allowed the creation of detailed maps of terrain and vegetation.

Spark: a new insight into bushfire spread simulation

Fire spread simulation is an intersection of a number of disciplines including ecology, geography, physics, meteorology, mathematics and computer science. When simulating fires, each of these must work together.

To do this most effectively, a new way to bring all of these parts together was needed. This led to the creation of a new software system called Spark.

Spark is a bushfire prediction framework containing all the parts needed to process fine-scale weather and fuel data, run advanced fire simulations and depict the results. The system will be released today at the Australia New Zealand Disaster Management Conference on the Gold Coast.

The parts that make up Spark can also be connected together in whichever way best suits the user. This also has the advantage that as new models come along, the older parts in the system can simply be replaced.

The system enables scientists from multiple disciplines to collaborate. Currently, fire scientists are working to improve fire behaviour models, computer scientists are building new ways to simulate perimeter propagation and software engineers are developing the system on the latest computational hardware.

Spark has been built with the uncertainty of fire behaviour foremost in mind. For predictions of ongoing fires, multiple different cases can be run for slightly different weather forecasts.

The system contains statistical components that allow the results to be combined into maps of the likelihood of when the fire is going to arrive at a given location.

Other current research involves improving fire predictions by using a range of conditions, some likely and others very unlikely.

These predictions can be combined with real-world measurements of the fire using a statistical method to feed back into the model. This allows the model to respond to changing conditions, including highly unlikely events, providing better predictions of future fire behaviour.

Software

Spark in action on a bushfire.

Bringing the latest fire science to the fireground

The collaborative approach behind Spark means that services and agencies using the system will benefit from the latest advances in fire science.

The system can be fully customised and can be integrated with existing systems. Spark can also be built into any number of applications, such as evacuation planning or fire regime tools.

Spark can also be used for land management and planning, fire mitigation analysis, real-time fire prediction, risk analysis or reconstruction and analysis of fire events.

The Conversation

James Hilton is Research scientist at CSIRO.
Andrew Sullivan is Research Team Leader, Bushfire Behaviour and Risks at CSIRO.
Mahesh Prakash is Principal Research Scientist, Fluid Dynamics at CSIRO.
Ryan Fraser is Research Manager at CSIRO.

This article was originally published on The Conversation.
Read the original article.


Farming carbon can be a win for wildlife, if the price is right

Koalas are one of the threatened species that could benefit from carbon farming. christopher charles/Flickr, CC BY-NC-SA

Koalas are one of the threatened species that could benefit from carbon farming. christopher charles/Flickr, CC BY-NC-SA

Megan Evans, Australian National University; Anna Renwick, The University of Queensland; Josie Carwardine, CSIRO, and Tara Martin, CSIRO

Climate change and the loss of biodiversity are two of the greatest environmental issues of our time. Is it possible to address both of those problems at once?

In Australia, farmers and landholders will this week be able to apply for payments through the Federal government’s A$2.55 billion Emissions Reduction Fund. Bidders can request funding for projects that reduce emissions using agreed methods, which include approaches relevant to the transport, waste and mining sectors, as well as the land sector: for example, by managing or restoring forests.

Forests hold carbon in vegetation and soils and provide important habitat for native wildlife. Restoring forests in areas where they have been cleared in the past could be good for the climate, good for biodiversity, and generate additional income for landholders.

How well the Emissions Reduction Fund can achieve these benefits will depend on three things: the right approach, the right price, and the right location.

Farming carbon

There are a range of approaches available for restoring forests, and they vary in how quickly carbon can be sequestered, cost, and suitability for wildlife.

For example, fast-growing monocultures such as blue gum plantations can sequester carbon very rapidly, but don’t provide ideal habitat for wildlife. Planting a diversity of native trees and shrubs using an approach called environmental plantings is far more wildlife-friendly, but the costs are higher, and carbon is not stored as quickly.

A third possible approach is to assist the natural regeneration of vegetation. This can be done by fencing off cattle or by ceasing on-farm practises such as burning or disturbance with machinery. Assisted natural regeneration is the cheapest of these three possible methods, and is also good for biodiversity: our recent paper found that it could be a great option for restoring forests in agricultural landscapes across Queensland and northern New South Wales.

Brigalow woodlands allowed to regrow for 3-10 years. Image: John Dwyer

Regenerated brigalow woodlands after 50 years. Image: John Dwyer

Location, location, location

Across Australia, there are a number of places where growing carbon could be a more profitable option than the current land use. Some of these places are more important for biodiversity than others.

The mulga lands of western Queensland may be worth more as carbon farms than other uses. Image: Don Butler

If we’re interested in getting some wins for biodiversity while growing carbon forests, we need to think carefully about the possible opportunities and trade-offs, as the best places for sequestering carbon are not always the most beneficial for biodiversity, and vice versa.

In our recent paper, we found that it is possible to identify where growing forests could provide win-wins for both carbon and biodiversity.

For example, the top 25% of priority areas for environmental plantings could sequester 132 million tonnes of CO2 equivalent annually, which is almost a quarter of Australia’s annual emissions (excluding those caused by land-use change).

Relative priority areas for restoring 139 threatened ecosystems to 30% of original extent using environmental plantings, where carbon is stored at $20/tonne. Pink areas are higher priority, green is lower priority http://bioscience.oxfordjournals.org/content/65/4/372

These high-priority areas for environmental plantings could restore some of the most threatened ecosystems in Australia. There are 139 ecosystem types across the country that have lost more than 70% of their original extent. If it were possible to restore these ecosystems up to 30% of their original extent, they will have a better chance of surviving in the long term.

Restoring parts of the landscape with these ecosystems is a high priority for biodiversity – not only are the ecosystems rare, but many of the birds and animals that depend on these ecosystems are those that are most threatened. For example the brigalow woodlands of south east Queensland, of which less than 10% remain, are home to nationally threatened koalas and a host of other wildlife.

The right price

It will generally be more expensive to grow carbon forests that also provide benefits for biodiversity. This is because the places most profitable for land uses such as agriculture are often where the most threatened species and ecosystems are located.

In our analysis, we found that with a price on carbon equivalent to A$5 per tonne, it would not be profitable to restore threatened ecosystems up to 30% of their original extent. This means that without additional funding from another source, there is limited opportunity to achieve wins for biodiversity if the price on carbon is low.

However, a higher price of A$20 per tonne, reflecting Australia’s 2011-2013 carbon price, could allow up to half of the heavily cleared vegetation types to be restored up to 30% without any additional funding for biodiversity itself. At this A$20 price, we also found that it made more economic sense to farm carbon than the existing land use, in over 1.2 million hectares in Queensland.

This week’s Emissions Reduction Fund auction will be a good first test of how the current approach to carbon farming can provide the dual benefit of restoring habitat for native wildlife and addressing climate change. Our analysis shows that Australia’s climate policies could have a very significant impact on biodiversity – if we think carefully about the right approach, price, and location.

The Conversation

This article was originally published on The Conversation.
Read the original article.


Follow

Get every new post delivered to your Inbox.

Join 4,683 other followers