̽��ֱ�� of Cambridge - Mining

Thousands of birds and fish threatened by mining for clean energy transition

jg533 — Fri, 26 Jul 2024 15:00:57 +0000

New research has found that 4,642 species of vertebrate are threatened by mineral extraction around the world through mining and quarrying, and drilling for oil and gas.

Mining activity coincides with the world's most valuable biodiversity hotspots, which contain a hyper-diversity of species and unique habitats found nowhere else on Earth.

̽��ֱ��biggest risk to species comes from mining for materials fundamental to our transition to clean energy, such as lithium and cobalt – both essential components of solar panels, wind turbines and electric cars.

Quarrying for limestone, which is required in huge amounts for cement as a construction material, is also putting many species at risk.

̽��ֱ��threat to nature is not limited to the physical locations of the mines - species living at great distances away can also be impacted, for example by polluted watercourses, or deforestation for new access roads and infrastructure.

̽��ֱ��researchers say governments and the mining industry should focus on reducing the pollution driven by mining as an ‘easy win’ to reduce the biodiversity loss associated with mineral extraction.

This is the most complete global assessment of the threat to biodiversity from mineral extraction ever undertaken. ̽��ֱ��results are published today in the journal Current Biology.

“We simply won’t be able to deliver the clean energy we need to reduce our climate impact without mining for the materials we need, and that creates a problem because we’re mining in locations that often have very high levels of biodiversity,” said Professor David Edwards in the ̽��ֱ�� of Cambridge’s Department of Plant Sciences and Conservation Research Institute, senior author of the report.

He added: “So many species, particularly fish, are being put at risk through the pollution caused by mining. It would be an easy win to work on reducing this freshwater pollution so we can still get the products we need for the clean energy transition, but in a way that isn’t causing so much biodiversity loss.”

Across all vertebrate species, fish are at particularly high risk from mining (2,053 species), followed by reptiles, amphibians, birds and mammals. ̽��ֱ��level of threat seems to be linked to where a particular species lives and its lifestyle: species using freshwater habitats, and species with small ranges are particularly at risk.

“ ̽��ֱ��need for limestone as a core component of construction activity also poses a real risk to wildlife. Lots of species are very restricted in where they live because they're specialised to live on limestone. A cement mine can literally take out an entire hillside - and with it these species’ homes,” said Ieuan Lamb in the ̽��ֱ�� of Sheffield’s School of Biosciences, first author of the report.

̽��ֱ��Bent-Toed Gecko, for example, is threatened by limestone quarrying in Malaysia – it only exists on a single mountain range that planned mining activity will completely destroy.

To get their results, the researchers used International Union for the Conservation of Nature (IUCN) data to see which vertebrate species are threatened by mining. By mapping the locations of these species they could investigate the types of mining that are putting species at risk, and see where the risks are particularly high.

̽��ֱ��researchers discovered that species categorised as ‘vulnerable, endangered, or critically endangered’ are more threatened by mineral extraction than species of lesser concern.

Watercourses can be affected in many ways, and water pollution can affect hundreds of thousands of square kilometres of rivers and flood plains. Mining sand as a construction material, for example, alters patterns of water flow in rivers and wetlands, making birds like the Indian Skimmer more accessible to predators.

Mineral extraction threatens vertebrate species populations across the tropics, with hotspots in the Andes, coastal West and Central Africa, and South-East Asia – which coincide with high mine density. For example, artisanal small-scale alluvial gold mining in Ghana threatens important bird areas through environmental mercury pollution.

Global demand for metal minerals, fossil fuels and construction materials is growing dramatically, and the extraction industry is expanding rapidly to meet this demand. In 2022 the revenue of the industry as a whole was estimated at US $943 billion.

Biodiversity underpins the protection of the world’s carbon stocks, which help to mitigate climate change.

̽��ֱ��study focused only on vertebrate species, but the researchers say mining is also likely to be a substantial risk to plants and invertebrates.

“There's no question that we are going to continue to mine - our entire societies are based on mined products. But there are environmental tensions embodied in our use of these products. Our report is a vital first step in avoiding biodiversity loss amidst the predicted drastic expansion of the mining industry,” said Edwards.

“Wildlife is more sensitive to mining in some regions of the world than in others, and our report can inform choices of where to prioritise getting our minerals to cause the least damage to biodiversity. Future policy should also focus on creating more circular economies - increasing recycling and reuse of materials, rather than just extracting more,” said Lamb.

̽��ֱ��research was funded by the Hossein Farmy scholarship.

Reference: Lamb, I P, ‘Global threats of extractive industries on vertebrate biodiversity.’ Current Biology, July 2024. DOI: 10.1016/j.cub.2024.06.077

Our increasing demand for metals and minerals is putting over four thousand vertebrate species at risk, with the raw materials needed for clean energy infrastructure often located in global biodiversity hotspots, a study has found.

Our report is a vital first step in avoiding biodiversity loss amidst the predicted drastic expansion of the mining industry.

David Edwards

Gold mine in Rondonia, Amazonian Brazil

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Opinion: Worthless mining waste could suck CO₂ out of the atmosphere and reverse emissions

Anonymous — Thu, 20 Apr 2017 16:06:39 +0000

̽��ֱ��Paris Agreement commits nations to limiting global warming to less than 2˚C by the end of the century. However, it is becoming increasingly apparent that, to meet such a massive challenge, societies will need to do more than simply reduce and limit carbon emissions. It seems likely that large scale removal of greenhouse gases from the atmosphere may be called for: so-called “negative emissions”.

One possibility is to use waste material from mining to trap CO₂ into new minerals, locking it out of the atmosphere. ̽��ֱ��idea is to exploit and accelerate the same geological processes that have regulated Earth’s climate and surface environment over the 4.5 billion years of its existence.

Across the world, deep and open-pit mining operations have left behind huge piles of worthless rubble – the “overburden” of rock or soil that once lay above the useful coal or metal ore. Often, this rubble is stored in dumps alongside tiny fragments of mining waste – the “tailings” or “fines” left over after processing the ore. ̽��ֱ��fine-grained waste is particularly reactive, chemically, since more surface is exposed.

A lot of energy is spent on extracting and crushing all this waste. However, breaking rocks into smaller pieces exposes more fresh surfaces, which can react with CO₂. In this sense, energy used in mining could itself be harvested and used to reduce atmospheric carbon.

This is one of the four themes of a new £8.6m research programme launched by the UK’s Natural Environment Research Council, which will investigate new ways to reverse emissions and remove greenhouse gases from the atmosphere.

Spoil tips from current and historic mining operations, such as this gold mine in Kazakhstan, could provide new ways to draw CO₂ from the atmosphere. Photo Credit: Ainur Seitkan, Earth Sciences, ̽��ֱ�� of Cambridge

̽��ֱ��process we want to speed up is the “carbonate-silicate cycle”, also known as the slow carbon cycle. Natural silicate rocks like granite and basalt, common at Earth’s surface, play a key part in regulating carbon in the atmosphere and oceans by removing CO₂ from the atmosphere and turning it into carbonate rocks like chalk and limestone.

Atmospheric CO₂ and water can react with the silicate rocks to dissolve elements they contain like calcium and magnesium into the water, which also soaks up the CO₂ as bicarbonate. This weak solution is the natural river water that flows to the oceans, which hold more than 60 times more carbon than the atmosphere. It is here, in the oceans, that the calcium and bicarbonate can recombine, over millions of years, and crystallise as calcite or chalk, often instigated by marine organisms as they build their shells.

Today, rivers deliver hundreds of millions of tonnes of carbon each year into the oceans, but this is still around 30 times less than the rate of carbon emission into the atmosphere due to fossil fuel burning. Given immense geological time scales, these processes would return atmospheric CO₂ to its normal steady state. But we don’t have time: the blip in CO₂ emissions from industrialisation easily unbalances nature’s best efforts.

̽��ֱ��natural process takes millions of years – but can we do it in decades? Scientists looking at accelerated mine waste dissolution will attempt to answer a number of pressing questions. ̽��ֱ��group at Cambridge which I lead will be investigating whether we can speed up the process of silicate minerals from pre-existing mine waste being dissolved into water. We may even be able to harness friendly microbes to enhance the reaction rates.

Another part of the same project, conducted by colleagues in Oxford, Southampton and Cardiff, will study how the calcium and magnesium released from the silicate mine waste can react back into minerals like calcite, to lock CO₂ back into solid minerals into the geological future.

Whether this can be done effectively without requiring further fossil fuel energy, and at a scale that is viable and effective, remains to be seen. But accelerating the reaction rates in mining wastes should help us move at least some way towards reaching our climate targets.

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

Could waste material from mining be used to trap CO₂emissions? A new £8.6 million research programme will investigate the possibilities. Simon Redfern (Department of Earth Sciences) explains, in this article from ̽��ֱ��Conversation.

Mundus Gregorius

Tagebau / Open cast mine

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Fingerprinting rare earth elements from the air

lw355 — Fri, 01 Jul 2016 09:00:00 +0000

Next time you use your mobile phone, spare a moment for the tiny yet vital ingredients that make this and many other technologies possible – the rare earth elements (REEs).

Used in computers, fibre optic cables, aircraft components and even the anti-counterfeiting system in euro notes, these materials are crucial for an estimated £3 trillion worth of industries, with demand set to increase over the coming decades.

Currently, more than 95% of the global demand for the REEs is met by a single mine in China. ̽��ֱ��security of the future supply of these 17 critical metals, which include neodymium, europium, terbium, dysprosium and yttrium, is a major concern for European governments, and the identification of potential REE resources outside China is seen as a high priority.

Over the past year, Drs Sally Gibson, Teal Riley and David Neave have been working together through a ̽��ֱ�� of Cambridge–BAS Joint Innovation Project (see panel) on a remote sensing technique that could aid the identification of REEs in rocks anywhere in the world. ̽��ֱ��project brings together expertise in remote sensing, geochemistry and mineralogy from both institutes to take advantage of the properties that make the metals so special.

“Despite their name, the rare earth elements are not particularly rare and are as abundant in the Earth’s crust as elements such as copper and tin,” explains Riley from BAS. “However, to be extractable in an economic way, they need to be concentrated into veins or sediments.” It’s the identification of these concentrations that is critical for the future security of supply. REEs all have an atomic structure that causes them to react to photons of light through a series of electronic transitions. This gives them the magnetic and electrical properties for which they are prized in plasma TVs, wind turbines and electric car batteries. And it also means that for every photon of light they absorb, they reflect other photons in a unique way – it is this property that the researchers have latched onto as a means of tracking them down.

“ ̽��ֱ��light they reflect is so specific that it’s like a fingerprint, one that we can capture using sensors that pick up light emissions,” explains Gibson, from Cambridge’s Department of Earth Sciences. “ ̽��ֱ��difficulty, however, is that in naturally occurring rocks and minerals, the rare earth element emission spectra are mixed up with those of other elements. It’s like looking at overlapping fingerprints – the challenge was to work out how to tease these spectral fingerprints apart.”

Gibson has over 20 years’ experience investigating how REEs are generated during the melting of the Earth’s mantle. “Collective understanding of the geological make-up of the world is now good enough that we know where to look for these rocks – at sites of a certain type of past tectonic activity – but even then it’s difficult to find them.”

Riley is the head of the Geological Mapping Group at BAS – his job is to “map the unmapped” areas of the polar region to understand the geological evolution of the continent. Much of his work depends on being able to develop new ways of interrogating satellite- and aircraft-based remote sensing data. “It became a frustration that we could collect data and say generally what was on the ground but that we couldn’t define individual fingerprints, and so we developed the analytical tools to do this.”

Gibson and Neave gathered rocks containing REE-bearing minerals from around the world – sourced from mining companies, museum collections and universities. One such source was the Harker Collection housed in the ̽��ֱ��’s Sedgwick Museum of Earth Sciences. This collection contains specimens of minerals and rocks rich in REEs that were collected decades previously by geologists who were unaware of their economic importance.

Neave analysed the emission spectrum of each rock and related this to its gross and microscopic composition. From this information he began to untangle the individual fingerprints, resulting in what the researchers believe is the most comprehensive ‘spectral database’ of REEs in their natural state – in rocks.

̽��ֱ��next goal is to use this spectral database as a reference source to track down deposits from the air. “Although data from aircraft is now good enough to be analysed in this way, we are waiting for new satellite missions such as the German Environmental Mapping and Analysis Program (EnMAP) to be launched in the next few years,” explains Riley. ̽��ֱ��plan would then be to carry out reconnaissance sweeps of the most likely terrains and explore the possibility of mining these areas. “Our hope is that this research will help to create an internationally unique and competitive capability to map these surprisingly common – yet difficult to find – materials,” adds Gibson.

Vital to many modern technologies yet mined in few places, the ‘rare earth elements’ are in fact not that rare – they are just difficult to find in concentrations that make them economic to mine. Researchers from Cambridge ̽��ֱ�� and the British Antarctic Survey (BAS) are investigating whether the remarkable properties of these materials can be used to track them down from the air.

̽��ֱ��light they reflect is so specific that it’s like a fingerprint, one that we can capture using sensors that pick up light emissions

Sally Gibson

Aurora Cambridge

̽��ֱ��search for rare earth elements is one of a host of ongoing projects between the ̽��ֱ�� and BAS. Like these, a new centre – Aurora Cambridge – will reflect the ethos that innovation developed for the Antarctic is transferable to a global setting.

Aurora Cambridge aims to generate new research and entrepreneurial activity focused on climate change and challenging environments through academic, business and policy partnerships. It will be located at BAS in Cambridge and has been funded by the National Environment Research Council with support from the ̽��ֱ��.

̽��ֱ��building is due to open in 2017; however, 27 ̽��ֱ�� of Cambridge–BAS Joint Innovation Projects are already under way with funding from the Higher Education Funding Council for England – including the development of mapping technologies for rare earth elements led by Drs Sally Gibson and Teal Riley.

Other projects include research on cold-adapted enzymes with potential applications in the biotech industries, remote sensing for conservation of seabirds and marine mammals, and the measurement of coastal vulnerability through sea-level rise. Many involve external industrial partners and other research institutions as well as researchers from BAS and 12 ̽��ֱ�� departments.

“ ̽��ֱ��collaborative projects demonstrate not only the importance of research technology to the Antarctic but also their transferability beyond its shores to a global setting,” explains BAS Director of Innovation Dr Beatrix Schlarb-Ridley. “ ̽��ֱ��SPECTRO-ICE project, for instance, has brought scientists at BAS who are concerned with monitoring the atmosphere above the ice cap together with physicists and mathematicians who are working hard to avoid seeing the atmosphere in their study of the stars – both use similar techniques and need to operate advanced instruments at difficult locations.”

“This is just the beginning,” says BAS Director Professor Jane Francis. “ ̽��ֱ��new innovation centre will help us to extend the range of fruitful partnerships with academia, business, policy makers and the third sector to create tangible benefits for society.”

www.bas.ac.uk/aurora-cambridge

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Opinion: What science can tell us about the ‘world’s largest sapphire’

Anonymous — Wed, 06 Jan 2016 14:31:13 +0000

̽��ֱ��“Star of Adam”, recently found in a mine in Sri Lanka, is believed to be the biggest sapphire ever discovered. It weighs in at over 1,404 carats, that’s around 280g or just under ten ounces. But what do we know about the formation of this remarkable gemstone – and how could it grow so huge?

Sapphire is a bright blue gem mineral and a form of corundum (aluminium oxide), the hard gritty stuff used as an abrasive in emery paper. It is incredibly hard – a fact important in understanding its occurrence in places like the Sri Lankan mines.

Sapphire is a type of “dirty” corundum. If you add just a trace of iron and titanium to the mixture of aluminium and oxygen from which the corundum is growing, it forms as sapphire. (If you add chromium to the corundum as it grows then you will get a ruby – Sri Lanka is also famous for its rubies).

̽��ֱ��Star of Adam sapphire is an example of a “star sapphire”. When you look at it it appears to have a six-pointed star inside, which shines out from the gem and is due to reflections of light from tiny whisker-like crystals of rutile (a titanium-dioxide mineral) that were trapped within the sapphire crystal as it grew.

Ancient river sediments

̽��ֱ��stone was found in the Ratnapura mines in the south of the country, about 100km south-east of the capital, Colombo. Ratnapura is Singhalese for “gem town” and Sri Lanka has been known for its gem deposits for more than 2,000 years. It seems likely that Sinbad’s “Valley of Gems” in the Tales of the Arabian Nights is a reference to the Ratnapura area. In 1292, Marco Polo wrote: “ ̽��ֱ��Island of Ceylon is, for its size, the finest island in the world, and from its streams come rubies, sapphires, topaz, amethyst and garnet."

Ratnapura gem mine. hassage/Flickr, CC BY-SA

̽��ֱ��gems of Ratnapura are found in ancient river sediments – old river beds that are now covered with more layers of mud and sand in an area that is largely given over to paddy fields. ̽��ֱ��hard gem minerals, sapphires, rubies, spinels and garnets, were long ago weathered and eroded from the nearby highlands. Because of their hardness they survived as large pebbles and crystals, eroded out of the rocks where they first formed, and transported down the rivers which acted like a natural panning system. River-borne (alluvial) gold and diamonds are often sorted and concentrated in river sands by similar processes, elsewhere on the globe.

On their journey along the river the softer rocks from the highlands would have been worn down into mud and fine sand, but the harder minerals survive better, and retain their size and often their shape. ̽��ֱ��average annual rainfall for the island is more than 2,000mm, and the tropical weather means that the erosion and weathering of the highland mountains is even more accelerated.

Ratnapura is in the “wet zone” of the island. Its gem-bearing gravels have yielded a number of historic gemstones, possibly including a 400-carat red spinel given to Catherine the Great of Russia, and a giant oval-cut spinel, known as the “Black Prince Ruby” (it was mistakenly identified as a ruby), which features in the British Queen’s imperial state crown.

̽��ֱ��Star of Adam sapphire would originally have been created within rocks and granites of the Sri Lankan highlands. ̽��ֱ��granites, which form when molten magma cools and becomes solid, have been dated as almost two billion years old, and were subsequently squeezed and re-worked in a massive mountain-building episode due to tectonic churning of the Earth’s crust that happened more than 500m years ago.

Temperatures and pressures deep within the roots of these mountains would have reached more than 900˚C and over 9,000 atmospheres pressure during this event. ̽��ֱ��sapphire could have formed either within the granite, as part of a rock type called a pegmatite, or within the younger rock created by pressurisation and heating.

In either case the temperatures and pressures would have changed only very slowly over millions and millions of years, and this is how the crystal was able to grow so big. Once formed, the mountains that it sat within would have been eroded and uplifted, and so it was brought to the surface, picked out of the rock by the forces of rain and weathering, and transported down river to the gem sands of Ratnapura. Today it sits in the hands of a private owner.

Simon Redfern, Professor in Earth Sciences, ̽��ֱ�� of Cambridge

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

̽��ֱ��opinions expressed in this article are those of the individual author(s) and do not represent the views of the ̽��ֱ�� of Cambridge.

Simon Redfern (Department of Earth Sciences) discusses how the "Star of Adam" sapphire was formed in the highlands of Sri Lanka.

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̽��ֱ��Star of Adam

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