Deep Earth structures may reveal location of untapped base metal deposits

Researchers from the United States and Australia have discovered previously unrecognized structural lines 100 miles or more down in the Earth that appear to signal the locations of giant deposits of copper, lead, and zinc. The metals, however, lie close enough to the surface to be mined, but too far down to be found using current exploration methods. 

In a paper published in the journal Nature Geoscience, scientists at Harvard University, Columbia University, Geoscience Australia and the Australian National University say this discovery could greatly narrow down search areas, and reduce the footprint of future mines.

In detail, the study found that 85% of all known base metal deposits hosted in sediments —and 100%t of all deposits that hold more than 10 million tonnes of metal— lie above deeply buried lines girdling the planet that mark the edges of ancient continents.

The study promises to open exploration in poorly explored areas, including parts of Australia, central Asia and western Africa

Specifically, the deposits lie along boundaries where the Earth’s lithosphere thins out to about 170 kilometres below the surface. Up till now, all such deposits have been found at the surface, and their locations have seemed to be somewhat random. 

To find them, geologists normally hammer rocks or use geophysical exploration methods that entail harnessing gravity and other parameters to find buried ore bodies. The new study proposes a new, high-tech treasure map that provides more accurate information so that prospectors know where to look.

To build such a map, the researchers build on existing charts created using seismic waves that reveal the highly variable depth of the lithosphere, which ranges down to 300 kilometres in the nuclei of the most ancient, undisturbed continental masses, and tapers to near zero under the younger rocks of the ocean floors. 

“As continents have shifted, collided and rifted over many eons, their subsurfaces have developed scar-like lithospheric irregularities, many of which have now been mapped,” the experts explained in a media release.

Using this information, the authors of the study found that the richest Australian mines lay neatly along the line where thick, old lithosphere grades out to 170 kilometres as it approaches the coast. They then expanded their investigation to some 2,100 sediment-hosted mines across the world, and found an identical pattern. Some of the 170-kilometre boundaries lie near current coastlines but many are nestled deep within the continents, having formed at various points in the distant past when the continents had different shapes.

Thus, their new map shows such zones looping through areas in western Canada, the coasts of Australia, Greenland and Antarctica; the western, southeastern and Great Lakes regions of the United States; and much of the Amazon, northwest and southern Africa, northern India and central Asia. While some of the identified areas already host enormous mines, others are complete blanks on the mining map.

“These deposits contain lots of metal bound up in high-grade ores, so once you find something like this, you only have to dig one hole,” said Mark Hoggard, lead author of the paper and a postdoctoral researcher at Harvard University and Columbia University’s Lamont-Doherty Earth Observatory. “Most current base-metal mines are sprawling, destructive open-pit operations. But in many cases, deposits starting as far down as a kilometre could probably be mined economically, and these would almost certainly be taken out via much less disruptive shafts.”

In Hoggard’s view, this study promises to open exploration in poorly explored areas, including parts of Australia, central Asia and western Africa.

Oldest ocher mine in the American continent discovered in Mexico

Archaeologists and cave divers found in Mexico what they believe is the oldest known mine in the American continent.

In a paper published in the journal Science Advances, the explorers explain that a flooded cave in the southeastern state of Quintana Roo hosts irrefutable evidence of prehistoric mining activities that were carried out some 10,000 to 12,000 years ago.

According to the researchers, lab analyses show that La Mina – ‘The Mine’ in Spanish, the name they gave to the area – was active roughly during the same period when Naia was alive. Naia was a young prehistoric woman whose remains were found in 2014 inside the Hoyo Negro (Black Hole) archaeological site located near Tulum.

Oldest ocher mine in the American continent. (Image by Sam Meacham, courtesy of CINDAQ).

“La Mina is a continuation of Hoyo Negro not only because of their relative geographical proximity but also because the archaeological context of the former greatly complements the existing knowledge surrounding the latter,” said in a media statement Roberto Junco Sánchez, head of the Underwater Archaeology Sub-Directorate at the National Institute of Anthropology, the institution leading the project since 2017 together with the History and Research Centre of the Quintana Roo Aquifer System, known as CINDAQ in Spanish.

Junco Sánchez explained that while the discovery of Naia contributed to the understanding of the ascent, expansion and development of the first Americans, thanks to La Mina it is now possible to know that early humans not only risked their lives by entering the labyrinth of caves in search of water or to escape predators, but they also went inside them for mining purposes, thus altering them and creating cultural modifications within.

Such modifications were observed over a six-kilometre radius of uncharted underwater passageways that were previously concealed behind clusters of rocks and narrow passages. In these areas, various materials were rearranged as a result of archaic human intervention.

Among the elements that caught the explorers’ attention were heaps of coal on the floor, soot on the ceiling of the cave and small carved-out cavities on the ground, where traces of ocher were found. 

The location of the cave system remains confidential for conservation purposes

“The cave’s landscape has been noticeably altered, which leads us to believe that prehistoric humans extracted tonnes of ocher from it, maybe having to light fire pits to illuminate the space,” said Fred Devos, CINDAQ’s co-director and one of the divers who has been exploring the cave for about three years.

Until now, no human skeletal remains have been found, however, rudimentary digging tools, signs —that would have been used in order not to get lost— and stacks of stones left behind by this primitive mining activity have been located. The abundance of ocher filled cavities has led experts to theorize about the rocks themselves being used as tools to excavate and break down the stone.

Next steps

At this point, the team working at La Mina has accumulated 600 hours of diving, 100 immersions and 20,000 photos taken with technologies such as photogrammetry and 360 degrees underwater cameras.

The information gathered during the excursions will now be used by experts from Mexico, Canada and the United States to create a 3D model of the site that allows virtual access to archaeologists.

At the same time, the collected ocher and other materials will be analyzed at the DirectAMS laboratory in Bothell, Washington to know more precisely how old they are.

The DirectAMS lab consultant working on the project, James Chatter, described what his analyses tell him about what an operative La Mina used to look like. “Imagine a flickering light, in the middle of deep darkness, that at once illuminates the red-stained hands of the miners as they strike the ground with hammers made out of stalagmites, while it lights the way for those who carry the ocher through the tunnels until they reach sunlight and the forest floor.”

The location of the cave system remains confidential for conservation purposes.

Moon richer in metals than previously thought — NASA

Plans to start mining the Moon as early as 2025 became more attractive this week after a US National Aeronautics and Space Administration (NASA) team found evidence that the Earth’s natural satellite might, underneath its surface, be richer in metals than previously thought.

Using data from the Miniature Radio Frequency (Mini-RF) instrument onboard NASA’s Lunar Reconnaissance Orbiter (LRO), a team of researchers came to the conclusion that the lunar subsurface contains higher concentration of certain metals, such as iron and titanium, than estimated.

The study, published in the journal Earth and Planetary Science Letters, contends the most popular theory surrounding the Moon’s origins. The hypothesis contends the satellite was formed when a Mars-sized object collided with Earth, vaporizing large portions of Earth’s upper crust.

“By improving our understanding of how much metal the moon’s subsurface actually has, scientists can constrain the ambiguities about how it has formed, how it is evolving and how it is contributing to maintaining habitability on Earth,” lead study author Essam Heggy said in a statement.

The evidence was discovered while the scientists were looking for ice at the bottom of craters in the lunar north pole region, NASA said. It means that fine dust found at the base of those holes are  parts of the deeper layers of the Moon, ejected during meteor impacts. As such, this dust represents the composition in deeper Moon layers.

The researchers found a pattern in which larger and deeper craters have higher metal concentrations than smaller and shallower ones. Specifically, in craters approximately 1 to 3 miles wide, the dielectric constant or electrical property increased along with crater size. However, the electrical property remained constant for craters between three to 12 miles wide.

Order to mine

US President Donald Trump signed an order in April encouraging citizens to mine the Moon and other celestial bodies with commercial purposes.

The directive classifies outer space as a “legally and physically unique domain of human activity” instead of a “global commons,” paving the way for mining the moon without any sort of international treaty.

“Americans should have the right to engage in commercial exploration, recovery, and use of resources in outer space,” the document states, noting that the US had never signed a 1979 accord known as the Moon Treaty. This agreement stipulates that any activities in space should conform to international law.

Russia’s space agency Roscosmos quickly condemned Trump’s move, likening it to colonialism.

“There have already been examples in history when one country decided to start seizing territories in its interest — everyone remembers what came of it,” Roscosmos’ deputy general director for international cooperation, Sergey Saveliev, said.

The proposed global legal framework for mining on the moon, called the Artemis Accords, would be the latest effort to attract allies to the US National Space Agency’s (NASA) plan to place humans and space stations on the celestial body within the next decade.

It also lines-up with several public and private initiatives to fulfill the goal of extracting resources from asteroids, the moon and even other planets.

In 2015, the US Congress passed a bill explicitly allowing companies and citizens to mine, sell and own any space material.

That piece of legislation included a very important clause, stating that it did not grant “sovereignty or sovereign or exclusive rights or jurisdiction over, or the ownership of, any celestial body.”

The section ratified the Outer Space Treaty, signed in 1966 by the US, Russia, and a number of other countries, which states that nations can’t own territory in space.

Trump has taken a consistent interest in asserting American power beyond Earth, forming the Space Force within the US military last year to conduct space warfare where needed.

The country’s space agency NASA had previously outlined its long-term approach to lunar exploration, which includes setting up a “base camp” on the moon’s south pole. 

Trillion-dollar market

The US isn’t the first nor the only nation to jump on board the lunar mining train.

Russia has been pursuing plans in recent years to return to the moon, potentially travelling further into outer space.

Roscosmos revealed in 2018 plans to establish a long-term base on the moon over the next two decades, while President Vladimir Putin has vowed to launch a mission to Mars “very soon.”

Luxembourg, one of the first countries to set its eyes on the possibility of mining celestial bodies, created in 2018 a Space Agency (LSA) to boost exploration and commercial utilization of resources from Near Earth Objects.

Unlike NASA, LSA does not carry out research or launches. Its purpose is to accelerate collaborations between economic project leaders of the space sector, investors and other partners.

Thanks to the emerging European network, scientists announced last year plans to begin extracting resources from the moon as early as 2025.

The mission, in charge of the European Space Agency in partnership with ArianeGroup, plans to extract waste-free nuclear energy thought to be worth trillions of dollars.

Both China and India have also floated ideas about extracting Helium-3 from the Earth’s natural satellite. Beijing has already landed on the moon twice in the 21st century, with more missions to follow.

In Canada, most initiatives have come from the private sector. One of the most touted was Northern Ontario-based Deltion Innovations partnership with Moon Express, the first American private space exploration firm to have been granted government permission to travel beyond Earth’s orbit.

Space ventures in the works include plans to mine asteroids, track space debris, build the first human settlement in Mars, and billionaire Elon Musk’s own plan for an unmanned mission to the red planet.

Geologists as well as emerging companies, such as US-based Planetary Resources, a firm pioneering the space mining industry, believe asteroids are packed with iron ore, nickel and precious metals at much higher concentrations than those found on Earth, making up a market valued in the trillions.

MINING.COM MINUTE: Biggest stories of the week

MINING.COM MINUTE is a roundup of the biggest stories from the global mining and metals industry. Share and get up to speed in a mining minute.

This week’s top stories:

  • Landslide at Myanmar jade mine leaves at least 162 dead – Read more
  • Endeavour becomes West Africa’s top gold miner – Read more
  • BHP’s Cerro Colorado to scale down operations – Read more
  • Nevada Gold Mines exceeds expectations, says Barrick – Read more

Click here for last week’s roundup.

ESG policies boost mining investor confidence – report

On April 20, Teck Resources Ltd. (TSX:TECK.B) released a 76-page first-quarter financial report that reported an $800 million decline in earnings compared with Q1 2019, due in large part to the impact of a global pandemic.

And on May 20, Teck released a 114-page sustainability review for 2019 that details its progress on environmental, social and governance (ESG) issues.

That progress includes:

• A 279,000-tonne reduction in carbon dioxide (CO2) emissions since 2011;

• A 249-terajoule reduction in energy use;

•5,781 hectares of land reclamation;

• $225 million spent on aboriginal business procurement;

• $19 million in community investments; and

• 32% of new hires being women in 2019.

That report followed an announcement in March that Teck was committing to a 33% CO2 reduction by 2030.

Institutional investors are increasingly looking at ESG and sustainability reports because they have become earmarks of well-managed companies, according to Daniel O’Brien, PwC’s Western Canada lead for sustainable business solutions.

While the mining sector took a hit from the pandemic in 2020’s first half, as the world moves into recovery, O’Brien said there could be a significant influx of capital back into the markets, and companies with good ESG policies stand to benefit.

“That capital will largely be controlled by larger institutional investors that have a very strong viewpoint on ESG,” he said. “They see ESG as a proxy for a well-managed company.”

According to PwC’s annual report on mining in British Columbia, the province’s mining sector held up well in 2019, even though commodity prices began to fall in the latter part of the year.

“That capital will largely be controlled by larger institutional investors that have a very strong viewpoint on ESG. “They see ESG as a proxy for a well-managed company”

Daniel O’Brien, Western Canada lead for sustainable business solutions, PwC

And B.C. miners appear to have weathered the covid-19 pandemic better than some of their peers elsewhere. In some cases, it may be because some already have strong ESG policies, which would include health and safety measures that helped them address worker safety issues posed by covid-19.

Some companies in B.C. either reduced production or temporarily shut down some operations to address worker safety during the pandemic.

“In the last six weeks, we’ve seen many of those operations either come back online or return to full production levels,” said Mark Patterson, PwC’s B.C. mining leader.

While metallurgical coal prices are currently soft, gold prices are up, and even copper prices have risen recently – a possible early indicator of global economic recovery.

“In the gold space, we’ve obviously seen gold prices respond very positively to current circumstances of uncertainty,” Patterson said. “I think the expectation on the gold side would be … maybe growth in exploration and, in the longer term, hopefully development opportunities coming out of a higher gold price environment over the next little while.”

Michael Goehring, president of the Mining Association of BC, said the PwC report confirms how important mining is to the province.

It points to a $216 million increase in direct payments to government and increase of 1,563 direct jobs since 2017. The mining sector in B.C. had capital expenditures of $1.5 billion in 2019, compared with $1.1 billion in 2018.

The increases in revenue to government occurred even though revenue to mining companies in B.C. overall was down by $1 billion compared with 2018.

“The numbers point to the need for policymakers and the industry to work together to improve our province’s fiscal and regulatory conditions so our mines and smelters can compete and succeed in global markets,” Goehring said.

“I would argue, with the right policies in place, mining offers British Columbians a significant opportunity to help our economy grow and recover from covid-19.”

O’Brien said companies that take ESG policies seriously may stand a better chance of attracting investment capital.

“There’s some early indication that companies with a strong ESG profile – low risk related to ESG – are outperforming peers in terms of their financial performance and stock prices,” he said. 

“Mining companies that are doing a good job of reporting on ESG, and indicating how they’re progressing towards their targets and objectives, are going to be the ones that are well-positioned to attract that capital.” 

(This article first appeared in Business in Vancouver)

Goal of tailings management should be zero harm – report

An international group of 142 scientists, community groups and NGOs from 24 countries has published a set of 16 guidelines for the safer storage of mine waste.

The guidelines aim to protect communities, workers and the environment from the risks posed by thousands of mine waste storage facilities, which are failing more frequently and with more severe outcomes.

“Safety First: Guidelines for Responsible Mine Tailings Management” argues that the ultimate goal of tailings management must be zero harm to people and the environment and zero tolerance for human fatalities.

The group publishing the report includes frontline organizations in mining affected communities from Brazil, Tanzania, Papua New Guinea, India and elsewhere as well as global groups such as Amnesty International Canada, Earthworks, IndustriALL Global Union Federation, MiningWatch Canada, the Natural Resources Defense Council, The Movement of People Affected by Dams (MAB) and the Sierra Club.

Guidelines include that international safety protocols must be independent of company control, and must be established through multi-stakeholder processes

Last year, a tragic dam collapse in Brazil killed 270 people and destroyed the town of Brumadinho, and came on the heels of tailings dam failures at the Mount Polley mine in Canada and the Samarco mine in Brazil, among others.

The guidelines come as the Global Tailings Review, co-convened by the international mining industry association, ICMM, investors and the UN Environment Programme, prepares to unveil the first Global Tailings Standard “for the safer management of tailings storage facilities.”

Current industry standards, including the draft of the Global Tailings Standard released in 2019, do not adequately protect communities and ecosystems from failures, the report finds.

The trend in tailings dam tragedies are a consequence of allowing mining companies to sacrifice safety to cut costs, control auditors and silence dissent among workers, the report revealed.

Source: Earthworks

The report asserts that tailings storage facilities must be built and managed only with community consent, respecting human rights and the rights of Indigenous Peoples, adopting the best available technologies and practices.

Guidelines include that international safety protocols must be independent of company control, and must be established through multi-stakeholder processes that actively engage workers, communities and civil society.

Strong standards for tailings dams must ensure financial guarantees and accountability at the highest level of corporate governance, the report maintains.

Public participation in decisions and reliable whistleblower and grievance mechanisms are necessary to ensure that communities and workers can raise the alarm without consequences, the report finds.

“We need independent guidelines on tailings safety,” says Carolina de Moura of Associação Comunitária da Jangada, Brumadinho, Brazil. “We urgently need guidelines and regulations to manage toxic mine waste dams. We hope that the case of Brumadinho becomes a milestone and an inflection point for mining across the world.”

“Governments and international institutions need to move urgently to implement these 16 guidelines to end mine waste failures worldwide. Industry self-regulation will not provide adequate protection. There must be a strong global response to this global problem, putting safety first,” says Ugo Lapointe, MiningWatch Canada, Canada.

‘Hunter drone’ that flies at night could be used to find gemstone deposits

Researchers at The University of Hong Kong co-developed an autonomous ‘hunter drone’ that seeks out targets at night using a scanning laser. The mechanism could effectively be used to find new mineral deposits.

In a paper published in the journal Methods in Ecology and Evolution, the scientists explain that the application of laser-stimulated fluorescence (LSF) to an aerial system is possible because of the laser’s ability to project over great distances with little loss in power. 

The technique has been highly successful in paleontology, making fossil bones glow and revealing otherwise invisible details like skin and cartilage.

Hotspot on laser ‘scan strip’ produced by the Laser Raptor drone system is ~2cm wide fragment of a fossil mammal tooth. (Image courtesy of Thomas G Kaye & Michael Pittman, The University of Hong Kong)

Fluorescence is also extremely sensitive to differences in mineral composition so the new system’s creators believe it is ready to seek out a whole range of fluorescent targets including minerals, for example, to study rare and unusual geology or to search for gemstones.

The drone has been nicknamed ‘Laser Raptor’ and it is loaded with pre-programmed flight paths during the day.

Then, at night, it flies rapidly to search locations using its onboard navigation and then descends and maintains an altitude of 4 metres above ground so it can ‘mow the lawn’ in search of glowing targets as small as a thumbnail. After each “mission” is complete, a video of the laser scan is processed to find hotspots that are investigated the next day.

Co-creators Thomas Kaye and Michael Pittman said they are now working to develop LSF applications for the study of geologic landscapes beyond Earth.

#Mining Feeds BC Food Bank Challenge launched

AMEBC and Integra Resources have launched the #MiningFeedsBC Food Bank Challenge to help fundraise for Food Banks BC, specifically supporting food security efforts in rural, remote and Indigenous communities in British Columbia. So far the challenge has raised over C$30,000.   

Instead of simply straight donations (which are still accepted), the twist on this challenge is calling individuals and companies to also share their best “mining meal memory” on social media and challenging others.

Wheaton Precious Metals is stepping in with a corporate donation of C$25,000 and will match all additional donations up to C$25,000 to bring the total to C$100,000.

Learn more here.

Origin of British Crown Jewels’ diamond revealed

The famous Cullinan diamond, which is now the centrepiece of the British Crown Jewels, likely originated in Earth’s lower mantle, right beneath the rigid and stable continental plates, where the mantle is slowly moving or convecting.

The finding is part of ongoing research carried out by Evan Smith and Wuyi Wang at the Gemological Institute of America. The new insight was presented by Smith at the virtual 2020 Goldschmidt Conference organized by US-based Geochemical Society and the European Association of Geochemistry.

Smith and his team concluded that the Cullinan diamond was likely formed in the lower mantle and can be considered a ‘super-deep’ stone after examining an analog, large 124-carat diamond from Gem Diamonds’ (LON: GEMD) Letšeng mine in Lesotho.

According to the researchers, recent analyses of this walnut-sized diamond revealed that it contains remains of an important element: bridgmanite.

The Cullinan II or the Second Star of Africa, a diamond that weighs 317.4 carats, is mounted in the Imperial State Crown. (Image by Cyril Davenport, Wikimedia Commons).

“Finding these remnants of the elusive mineral bridgmanite is significant. It’s very common in the deep Earth, at the extreme pressure conditions of the lower mantle, below a depth of 660 kilometres, even deeper than most super-deep diamonds,” Smith said in his presentation. “Bridgmanite doesn’t exist in the upper mantle, or at the surface. What we actually see in the diamonds when they reach the surface is not bridgmanite, but the minerals left when it breaks down as the pressure decreases. Finding these minerals trapped in a diamond means that the diamond itself must have crystallized at a depth where bridgmanite exists, very deep within the Earth.”

By aiming a laser at the tiny inclusions trapped inside the diamond, the researchers found that the way the light scattered (using a Raman spectrometer) was characteristic of bridgmanite breakdown products.

The Letšeng mine diamond is so pure that it doesn’t contain nitrogen in its crystal structure. This characteristic classifies it as a ‘CLIPPIR’ diamond, which is the same category as that of the Cullinan diamond.

“What is special about this one is that it is the first CLIPPIR diamond for which we can firmly assign a lower mantle origin, that is, below 660 kilometres,” Smith said. “Previously, we had known that CLIPPIR diamonds are super-deep and speculated that their depth of origin might span 360 to 750 kilometres depth, but we hadn’t actually seen any that were definitely from the deeper end of this window.”

In the researcher’s view, this finding gives a better idea of exactly where CLIPPIR diamonds come from and also shows that there is some overlap in the birthplace for CLIPPIR diamonds and type IIb diamonds, such as the famous Hope diamond. This rare blue gem was owned by monarchs, bankers, heiresses and thieves until it landed at the Smithsonian National Museum of Natural History in Washington DC.

The overlap that Smith refers to points to a previous study in which the researcher showed that the Hope and other IIb diamonds originate in Earth’s deep mantle and that the boron that gives them a blue hue comes from the bottom of the oceans. To get into the diamond, the element is first dragged hundreds of kilometres by plate tectonics down into the mantle.

“It shows that there is a gigantic recycling route that brings elements from Earth’s surface down into the Earth, and then occasionally returns beautiful diamonds to the surface, as passengers in volcanic eruptions,” Smith said.

Pathways towards zero-emission copper mines

The International Copper Association Australia (ICAA) commissioned the University of Sydney’s Warren Centre for Advanced Engineering to develop a strategic roadmap to achieve a ‘zero-emission copper mine of the future.’

In a 68-page report, the Warren Centre explains that, typically, greenhouse gas emissions through the copper production process are associated with the consumption of fuel in the mining and materials transport processes and indirect emissions from electrical energy use in extractive and beneficiation processes.

“In general, the energy consumption in the primary copper process is dominated by the earlier stages of beneficiation. This is due to the high energy demand requirement to crush and grind ore. Within the mining process loading and hauling, blasting, and ventilation (in the case of underground mining) all consume a higher proportion of energy to other aspects of the mining process,” the document states.

Based on a literature review, the report concludes that the average energy intensity and GHG intensity is 2.6 t CO2-eq per tonne of copper produced, a figure that varies by location, extraction methodology, and ore grades.

Australian researchers present pathways towards zero-emission copper mines

To move towards a greener mine, the report says that one key strategy is to increase transparency and reporting. 

To achieve this, copper miners are asked to account for direct emissions, such as those from sources that are owned and controlled by companies, including onsite power generation; indirect emissions, which are those released into the atmosphere due to the consumption of an energy commodity, for example, emissions from the generation of purchased electricity to enable the copper production process; and finally, all other emissions that are generated indirectly as a result of activities from sources that are not owned or controlled by the company, like the emissions as a consequence of the use of the sold copper cathode for the manufacture of semi-fabricated products.

“Measurements of greenhouse gases are recorded relative to carbon dioxide equivalence (CO2-eq). For instance, a manufacturing or processing company emitting 1 tonne of methane into the atmosphere has the same global warming potential as emitting 25 tonnes of carbon dioxide. Hence, 1 tonne of methane would be expressed as 25 tonnes of carbon dioxide equivalence,” the report reads.

According to the document, emissions can be reported in absolute terms (total CO2-equivalent emissions, or CO2- eq) and intensity terms (CO2-eq per unit). Absolute measurements, however, should be combined with efficiency metrics to understand performance at a company or sector level.

The review recognizes that there are challenges associated with reaching the zero-emission goal, particularly how to achieve emission reduction outcomes while maximizing economic resource productivity at the industrial level, rather than simply offsetting or abating emissions associated with a given product cycle.

Besides transparent reporting, copper miners are encouraged to reach out to existing innovative mining equipment, technology and services (METS) businesses, which can be an important source of new ideas to address emission reduction pathways in the short and medium-term. 

According to the Warren Centre, METS can be key players for finding ways to reduce both costs and emissions through innovation, a path that should also include government and research institutions. 

“Applying advanced technologies at the discovery and exploration stage of the mining cycle will enable the development of robust ore-deposit identification and exploration models to improve the likelihood of detection of high-grade deposits in greenfield and brownfield sites. Advanced technologies can optimize attractive host rock settings and subsequent future ore recovery,” the document reads.

In a series of tables, the report presents specific segments of the discovery phase that can be addressed from existing or in-development innovations with the goal of reducing emissions. The tables are also presented for processes related to material movement, ventilation, mineral processing and water usage. 

Australian researchers present pathways towards zero-emission copper mines

In summary, when it comes to material movement, the Warren Centre’s proposal focuses on the need to further advances in the electrification of mining systems and the transition to automation in all aspects of the mining and material movement process. In particular, it highlights the importance of making use of incremental technologies that are able to deliver technical efficiencies with improved asset availability, reduced maintenance requirements, extended mine life, enhanced productivity and reduced emission outcomes.

For ventilation, the document points to shifts in technology, particularly autonomous systems that are allowing for the deployment of fewer people underground, which means that ventilation systems can be transitioned to be on-demand while power requirements are optimized. 

When it comes to mineral processing, targeted innovation efforts that should continue to be explored are technologies to improve crushing and grinding efficiencies, separation and concentrate drying, optimization of processing performance, in addition to measurement technologies to interconnect systems across the whole of plant operations and dry processing technologies.

There is also encouragement to adopt in-situ recovery mechanisms as they have the potential to be a low-impact and selective mining option because they imply the recovery of valuable metals from ore deposits by the circulation of fluid underground and the recovery of the valuable metal from the fluid at the surface for further processing. 

Addressing water usage, the report proposes a number of strategies that range from site stormwater capture, treatment and discharge to building slurry pipelines. However, the main focus is on industrial-scale desalination (reverse osmosis) technologies or the use of membrane technology to remove salts and other contaminants from water.

Even though the Centre recognizes that desalinization requires elevated energy inputs, the report also states that the growth in renewable technology is proving to be an effective offset mechanism to the high-energy intensive operations of desalination plants.