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.

India’s Coal Minister says mine auction yielding positive results

India’s Coal Minister Pralhad Joshi said that just a few days into the auction process of coal blocks to commercial mining operators, 1,140 parties have shown interest in taking part in this new chapter in the country’s mining history.

In mid-June 2020, Prime Minister Narendra Modi India announced that his administration was ending a four-decade state monopoly on the mining and selling of coal by auctioning to private companies 41 mines across the country.

In June, Prime Minister Narendra Modi India announced that his administration was ending a four-decade state monopoly on the mining and selling of coal

According to local media, 26 companies have already bought tender documents for about $6700 each and 10 firms expressed their interest in visiting the mines. Citing minister Joshi, the response is better than expected and should lead to more acquisitions in the short term.

But the process isn’t necessarily running smoothly. Out of the 41 mines, a site located in the western peninsular region of Maharashtra had to be withdrawn after being put up for auction because it is located in an eco-sensitive area.

At the same time, trade unions carried out a three-day strike this weekend to protest the government’s decision, an action that led to almost zero coal production at the mines.

Five of the unions also announced a new stoppage scheduled for August 18, 2020, and a plan to mobilize people in mining areas to sway public opinion against the auctioning of the mines.

Another challenge that the process is facing is that presented by the eastern Jharkhand state, whose Chief Minister Hemant Soren filed a petition in the Supreme Court against the central government’s decision to open coal mining to private investors. As of 2018, Jharkhand hosted the largest coal deposits in India, with 26.06% of total reserves which is equivalent to some 83.15 billion tonnes.

The offering of coal mines to private capital has two main objectives: solving a fuel shortage that threatens to choke the nation’s industrial activity and boosting India’s economy to help the country recover from the economic toll of the coronavirus pandemic.

Ecuador reports tailings dam breach in Azuay province

The Ecuadorian Ministry of Energy and Nonrenewable Natural Resources informed that a small tailings dam breached in the southern Azuay province, releasing about 50 tonnes of pollutants into the Tenguel river.

The accident was caused by the collapse of a retaining wall at the Armijos tailings station, located in the Camilo Ponce Enriquez area and operated by local firm Austro Gold. The released tailings were carried by a nearby creek into the river that is the source of fresh water for some adjacent farms and communities.

In a media statement, the Ministry said that it has ordered the stoppage of all mining activities at the site. Technical staff are conducting an investigation to determine the sanctions that will be imposed upon Austro Gold.

#ATENCIÓN | Colapsa piscina relaves de la compañía Austro Gold Ltda. en Ponce Enríquez. Se advierte la contaminación de los ríos El Tenguel y el Santa Martha.Más noticias >>

Posted by Diario El Mercurio on Friday, July 3, 2020
Video of the pollutants in the Tenguel river by Diario El Mercurio.

According to the government agency, lack of compliance with legal requirements by mine title owners could lead to the revocation of the mining permit. “Even if the mining permit is revoked, the former owner has to take responsibility for the environmental damages that were caused, restore the ecosystems and compensate people and communities,” the statement reads. 

There are approximately 100 small mining operations in the Camilo Ponce Enriquez area and about 60 of them have tailings facilities, many of which have been built without proper safety standards. To address this issue, the Ministry of Energy is currently working on a set of guidelines that are expected to be followed by mining companies when it comes to the design, construction and operation of tailings dams.

Ecuador is a country rich in gold and copper and since 2008, an estimated 1.8 million acres of the nation’s protected forests have been made available for mining exploration, according to the Rainforest Information Centre.

When it comes to big mining, the South American country has been gaining ground as an investment destination in recent years, with top miners entering into joint ventures or investing in juniors to gain exposure to projects in the country.

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.

‘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.

Only mill in the US able to process uranium-rare earth ores open for business

As the US pushes to dilute China’s monopoly and develop a domestic rare earth supply,  Colorado-based Energy Fuels (TSX: EFR) is working towards being at the forefront in the race.

Energy Fuels is the owner of the White Mesa Mill in Utah, the only fully-licensed and operating conventional uranium mill in the United States. The facility is normally used to process radioactive ore and produce yellowcake but now some areas are likely to be transformed to allow for the processing of uranium-rare earth ores.

“Our rare earth elements program intends to make the mill available for miners to process their uranium-rare earth ores in the US. Such a facility does not currently exist,” Mark Chalmers, president and CEO of Energy Fuels, told MINING.COM.

According to Chalmers, the mill’s ability to remove and recover uranium and manage the radioactive byproducts from rare earth ore potentially makes it a key link in the US rare earth supply chain. This is because many rare earth separation facilities are unable to handle uranium or the radioactive byproducts due to either technical or regulatory reasons, which explains why China’s rare earth industry is closely tied to its nuclear industry. 

“We are simply looking to do something similar in the US,” the executive said. 

It took Energy Fuels one year to assess the possibility of using the White Mesa mill to process REE ore streams and produce rare earth concentrates. Can you explain what this evaluation process consisted of?

Over the past year or so, we were approached by several private entities and the US government, asking about the capabilities of the White Mesa Mill in the rare earth space. So we began to educate ourselves. 

We discovered that uranium occurs in many rare earth minerals and that these elements need to be removed before the individual rare earth elements could be separated. Of course, uranium recovery is our main business. We began internal laboratory testing on a number of rare earth mineral samples and got very positive results. 

Only mill in the US able to process uranium-rare earth ores open for business
White Mesa mill tank. (Image courtesy of Energy Fuels).

We also began talking to rare earth industry folks who were not aware of the White Mesa Mill, and once they learned about our capabilities, they told us that the White Mesa Mill could fill a vital role in bringing rare earth production back to the US. 

We hired some exceptional consultants, including ANSTO, a mining consultancy group in Australia with considerable experience in rare earth mineral processing; Brock O’Kelley, who also has considerable experience in the mining and processing of rare earths in the US; and Constantine Karayannopoulos, who has substantial global experience and relationships in rare earth markets. At the current time, we think we are well on our way toward creating a viable rare earth business.

Will the mill have to undergo any modification to be able to process REE ore?

We are currently evaluating minor modifications to our operations at White Mesa Mill to enable the processing of uranium-bearing rare earth ores and to recover uranium and produce a rare earth concentrate. However, we do not believe significant investment will be required for our initial phases of rare earth recovery.

Can you explain how the process of removing and recovering uranium and thorium from rare earth ore works?

The mill has a long history of recovering uranium from a number of ores and alternate feed streams, including some that contained rare earths. We just didn’t attempt to recover those rare earths in the past. To create a rare earth concentrate, mill personnel will apply chemicals to the rare earth ores and place the rare earth elements, along with uranium, into solution. Then, the mill will use solvent extraction to remove the uranium and the radioactive byproducts. These processes are actually quite similar to what the mill has done over its 40-year operating history.

When do you plan to start this new phase? 

We intend to test and evaluate potential sources of rare earth element ores with the goal of entering into commercial processing arrangements with the owners of those ores, potentially as soon as late 2020 or early 2021. If the program is successful, we will produce rare earth oxide concentrates, which can then be sent to existing rare earth separation facilities for further processing.

Why is it important for a company like Energy Fuels to enter the REE market?

China is the dominant supplier of rare earth elements that are used in everything from smartphones to medical devices to clean energy production. The US government declared that rare earth elements are critical to our economy and national defense and has made it a priority to develop domestic production capabilities. 

We see an opportunity for our White Mesa Mill, which is already licensed and constructed, to help fill this critical gap and bring rare earth production capabilities back to the US. We don’t expect to significantly displace China in global rare earth markets. However, we would like to play a role in helping the US to rebuild our domestic capabilities.

A little bit of background

Energy Fuels acquired the White Mesa Mill as part of its acquisition of Denison Mines Corp. back in 2012. This transaction combined the only operating uranium mill in the US with Energy Fuels’ resources base.

Built in 1980, the facility has a licensed capacity of 8+ million pounds of uranium per year.

Ore from Energy Fuels mines in Utah, Arizona and Wyoming is crushed into smaller particles and delivered to the mill. Once there, expert personnel use a chemical solution to extract the uranium, which is concentrated and dried to create yellowcake. The yellowcake is then transported to a conversion facility to continue the process of creating nuclear fuel.

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.

Two decades after Los Frailes tailings accident, Guadiamar River shows signs of recovery

Researchers from the University of Seville just published a study where they state that there has been a fall in the total concentrations of metals in the Guadiamar River, two decades after the collapse of the tailings dam at the Los Frailes mine.

The accident took place on April 25, 1998, at Boliden Apirsa’s lead and zinc operation near Aznalcóllar in the province of Seville. On that day, a toxic waste reservoir failed and released 7 million cubic metres of effluent into the Guadiamar River. 

The researchers concluded that there has been an important fall in the total concentrations and evolution of the metal fraction towards their more innocuous forms

To evaluate how the river water has evolved after being polluted, the research group took samples back in 2002 and in 2018. Sediments were analyzed from six locations on the Guadiamar River and its main tributaries, from the area of the Aznalcóllar mine to the gates of Doñana National Park.

The samples taken were pre-treated using trituration, sifting and freeze-drying, to determine the concentration of aluminum, cadmium, copper, iron, manganese, lead and zinc. Then, the sequential extraction method of the European Commission Measurements and Testing Programme was used and modified to extract four different metal fractions, that is, interchangeable, reducible, oxidable and residual. For estimating the risks carried by the metal concentrations found in the sediments, the Potential Ecological Risk Index and the Sediment Quality Guide were used.

After comparing the samples, the researchers concluded that there has been an important fall in the total concentrations, and evolution of the metal fraction towards their more innocuous forms, so the environmental risk is much reduced.

“The risk coefficients calculated for the year 2002 showed an extreme risk with very high values for Cd, Pb and Zn in the whole area of study with the exception of the waters upstream of the mine,” the researchers said in a media statement. “In 2018, according to the data obtained, the risk had descended and moderated at the majority of the sample locations.”

According to the experts, despite the serious environmental consequences of the Aznalcóllar mining accident, their study shows that measures taken after the disaster were effective in improving the quality of the waters of the Guadiamar River and its main tributaries in relation to the dumping of acid water and pyrite muds. 

In their view, however, it is important to continue monitoring the quality of the water and sediments in the area to make sure they keep their current levels, to avoid any type of dumping and to prevent runoff from areas that are still contaminated. 

Less time underground, more autonomous tech/robots – the future of mine safety

Reliance on autonomous technology so that miners spend less and less time underground and using predictive analytics tools not only to assess rock mechanics but also workers’ wellbeing in and off-site, may become the pillars of mine safety in the future.

The conclusion was drawn from a webinar organized by technology company Exyn and where Vale’s Digital Leader, Anthony Downs, EY Canada Mining & Metals Industry Co-Leader, Theo Yameogo, and non-profit organization Norcat’s CEO, Don Duval, discussed the impacts of digital innovation in mine safety.

Better data are not only expected to show safer and more efficient ways to blast or drill but also to assess any condition that might inhibit workers’ ability to make sound decisions

According to the experts, mining companies are likely to continue investing in the deliberate deployment of technology and mine design to get the worker out of harm’s way. This means putting fewer workers underground and bringing in autonomous systems that have user interfaces that appeal to a younger generation. 

“I think we’re going to see a situation where a worker will go from sitting on one piece of equipment to supervising a handful of pieces of equipment all autonomously being tasked to do various things,” Downs said.

The new technology is also expected to capture better quality data which, in turn, should be used to drive better technical and strategic decisions. And these data are not only expected to show safer and more efficient ways to blast or drill but also to assess depression, fatigue, and anything that might inhibit workers’ ability to make sound decisions, particularly those that do need to get put into environments with a high degree of risk.

In the view of the presenters, assessing workers’ conditions should extend to what takes place once they leave the mine site, particularly when it comes to those working late hours. Previous experiences have shown that many of the safety-related injuries and issues, such as car accidents, happen off-site.  

Simulators and drones

The panellists brought to the table a recent trend that involves the use of equipment simulators for people that are learning how to operate specific equipment. 

“From a safety perspective, what I find fascinating is where they’re going, where they can essentially equip a sensor to gather data of the actual operator on the actual piece of equipment, gathering a series of data points on the operational effectiveness of that worker operating the equipment in an underground environment and then that data is fed back automatically to the simulator to customize a training program dealing with the problem areas that actual worker is dealing with in the field,” EY’s Yameogo said.

For Yameogo, these training mechanisms are likely to improve not only safety but also productivity. “Because underground not every situation will have an infrastructure to support digital. That’s often a problem in older mines. One of the major changes of the underground environment in the future is this ability of self-driven robotics, tools, and items, that do not require the mining company to make extensive changes to their infrastructure to have work.”

But changes, whether big or small, are already taking place either during the mine design phase or afterwards, as many sites have already started operating on WiFi, LTE, and 5G.

“The LTE network has really become the lifeline for us to do a whole range of different things underground, whether it’s enabling that autonomous or semi-autonomous equipment or enabling smart IoT sensors or whether it’s around worker and equipment tracking so that we know where they are if we need to evacuate a part of the mine we know who we need to go and look for,”  Vale’s Downs said.


Not only autonomous equipment is in the present and future of mine safety but according to the speakers, robots are as well. 

Citing studies by EY, Deloitte, Hatch and BDO, the speakers said the consensus is that by 2025-2027 robots will replace about 50% of the mineworkers thereby reducing mining accidents by close to 75%. 

“We can debate the timeline but I don’t think the mining industry has an innovation problem, they have challenges around adoption. And so the timeline on which we achieve this full integration and transformation of incorporating robots it might not be 2025 or 2027, but make no mistakes there is increasing shareholder pressure on these mining companies inspiring executives to be more creative than ever to invest in and deploy technologies that can enhance productivity and improve safety,” Norcat’s Duval said.

The presenters recognize that implementation of robotics is going to be different based on regional socioeconomic factors, however, they believe most operations will get there eventually. 

For them, robots are likely to be used to enhance the human in a way that makes their work easier and safer.  

“What if mine rescue had robots that actually are still going underground and the mine rescue team can do their work from the surface? We have achieved the same results, but without the rescue team going into an adverse condition,” Yameogo said.