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Mining Metals From Water | Earth Wise

March 14, 2023 By EarthWise Leave a Comment

Researchers at the Department of Energy’s Pacific Northwest National Laboratory in Richland, Washington are working with industry to develop a method of extracting valuable materials from various sources of water. The technique is the 21st-century equivalent of panning for gold in rivers and streams.

The patent-pending technology makes use of magnetic nanoparticles that are surrounded by an absorbent shell that latches on to specific materials of interest that are found in certain water sources. These sources could include water in geothermal power plants (known as geothermal brines), water pulled from the subsurface during oil or gas production, or possibly effluents from desalination plants. Extracting valuable materials from geothermal brines could greatly enhance the economics of geothermal power plants.

The initial focus of the development is on lithium, which is an essential element in many high-technology applications, especially in the batteries that power cell phones, computers, and electric cars. The global market for lithium is projected to reach over $8 billion a year by 2028 and very little of it is currently produced in the United States.

The tiny particles are added to the water and any lithium is drawn out of the water and is bound to them. Using magnets, the nanoparticles can be readily collected. Once the particles are no longer suspended in liquid, the lithium can easily be extracted, and the nanoparticles can be reused.

PNNL is developing the technology in partnership with a company called Moselle Technology as well as with other commercial partners. This new technology offers the promise of extracting critical materials in a quick, cost-effective manner.

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Tri-Cities Scientists “Magically” Mining Metals From Water

Photo, posted June 4, 2012, courtesy of Tom Shockey via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Lithium Mining And The Environment | Earth Wise

August 22, 2022 By EarthWise Leave a Comment

The Salar de Atacama in Chile is a large, dry salt flat surrounded by mountain ranges and is one of the driest places on Earth. Parts of the Atacama Desert have gone without rain for as long as people have been keeping track. Water rich in dissolved salts lies beneath this flat surface and it is particularly rich in lithium salts. Forty percent of the world’s known lithium deposits are the in the Salar.

Lithium is the key component of the batteries that power electric cars as well as cell phones and computers. It is an essential part of the transition away from fossil fuels and towards green energy. But it is important that this element is obtained responsibly with minimal damage to the environment.

Lithium, the lightest of the metals, tends to occur in layers of volcanic ash, but reacts quickly with water. It leaches into groundwater and settles in flat basins where it remains in a briny solution. This dense brine often ends up beneath pockets of fresh surface water, which are havens for fragile ecosystems.

A new study by the University of Massachusetts Amherst looked at the hydrological impact of lithium mining in the Salar. The study found that the impact of lithium mining depends critically on how long surface water is in place. Much of the fresh water there is at least 60 years old. Both droughts and extreme rainfall can cause major changes to the surface water that ordinarily comes from mountain runoff. Lithium mining itself only accounts for less than 10% of freshwater usage in the Salar. But the state of the surface water needs to be carefully monitored to protect the ecosystems as the climate continues to change.

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How environmentally responsible is lithium brine mining? It depends on how old the water is

Photo, posted February 21, 2016, courtesy of Jorge Pacheco via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Iron Flow Batteries | Earth Wise

November 15, 2021 By EarthWise Leave a Comment

Lithium-ion batteries power computers, cell phones, and increasingly, automobiles. They started out being rather expensive but have become dramatically cheaper over the last decade, with prices dropping about 90%. Batteries are needed to store clean power from wind and solar generation and lithium-ion batteries are increasingly being used for that purpose as well.

Utility-scale energy storage requires substantial battery installations and battery cost is still very much an inhibiting factor in the widespread adoption of the technology. Lithium-ion battery costs continue to drop but because they require expensive materials like lithium and cobalt, there are limits to how low their prices are likely to get.

As a result, researchers have continued to seek ways to produce batteries made out of cheaper materials. Among the more promising technologies are flow batteries, which are rechargeable batteries in which electrolyte flows through electrochemical cells from tanks.

Flow batteries are much larger than lithium-ion batteries and include physical pumps to move electrolytes. They typically are sold inside shipping containers. Clearly, such batteries are not suitable for use in vehicles, much less in consumer electronics. Nevertheless, they represent a practical option for grid storage.

A company called ESS has developed an iron flow battery suitable for utility energy storage. Clean energy firm CSB Energy plans to install iron flow batteries at several solar projects across the U.S. that will store enough energy to provide power 50,000 homes for a day. According to ESS, the iron-based batteries should sell for about half the price of lithium-ion batteries by 2025 and be able to store energy for longer periods.

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New Iron-Based Batteries Offer an Alternative to Lithium

Photo, posted March 21, 2021, courtesy of Nenad Stojkovic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Metals In Western Water Supplies | Earth Wise

October 29, 2021 By EarthWise Leave a Comment

A new study published by the University of Colorado Boulder looked at the problem of rivers being contaminated by acid rock drainage. Rocks that include sulfide-based minerals, such as pyrite, oxidize when exposed to air and water. The resulting chemical reaction produces sulfuric acid which, when present in water, dissolves metals like lead, cadmium, and zinc. The recent study found that rare earth elements are also leached out of rock by this process.

Rock drainage occurs naturally throughout the western United States, but historic mines that disturbed large amounts of rocks and soil have dramatically increased this process and have led to growing downstream water pollution. Upwards of forty percent of the headwaters of major rivers in the West are contaminated by some form of acid mine or rock drainage.

The warming climate has brought longer summers and less snow in winters. Longer, lower stream flows make it easier for metals to leach into watersheds and concentrate the metals that would otherwise be diluted by snowmelt.

Rare earth elements are essential components of many high-tech devices such as computers, hard drives, and cell phones. There is not a long history of studying the hazards they might represent when they enter the environment.

The study looked at the Snake River watershed in Colorado and found that increasing amounts of rare earth elements are entering Colorado water supplies. Concentrations of rare earth elements are not ordinarily monitored and there are no water quality standards set for them.

According to the researchers, once rare earth elements get into water, they tend to stay there. Traditional treatment processes don’t remove them. It is a growing problem that needs to be addressed.

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Rare earth elements and old mines spell trouble for Western water supplies

Photo, posted October 27, 2007, courtesy of Dion Gillard via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Better Batteries For The Grid | Earth Wise

September 14, 2021 By EarthWise Leave a Comment

As more and more solar and wind power is added to the electric grid, the need for ways to store the energy produced increases. Using batteries for this purpose is increasingly popular, mostly driven by the improving economics of the lithium-ion batteries used in electric vehicles as well as consumer electronics.

There are other battery technologies besides lithium ion that are not suitable for use in automobiles and cell phones but have potential advantages for the grid. One such technology is molten sodium batteries. These batteries have high energy density, a high efficiency of charge and discharge, and a long cycle life. They are fabricated with inexpensive materials and they are especially suitable for large-scale grid energy storage because their economics improves with increasing size.

A drawback of molten sodium batteries is that they operate at 520-660 degrees Fahrenheit, which adds cost and complexity. Researchers at Sandia National Laboratories have designed a new class of molten sodium batteries that operates at a much cooler 230 degrees Fahrenheit instead.

The battery chemistry that works at 550 degrees doesn’t work at 230 degrees. The Sandia group developed something they call a catholyte, which is a liquid mixture of two salts, in this case sodium iodide and gallium chloride. (Gallium chloride is rather costly, so the researchers hope to replace it in a future version of the battery).

By lowering the operating temperature, there are multiple cost savings including the use of less expensive materials, the requirement for less insulation, and the use of thinner wire.

This work is the first demonstration of long-term, stable cycling of a low-temperature molten-sodium battery. The hope is to have a battery technology that requires fewer cells, fewer connections between cells, and an overall lower cost to store electricity for the grid.

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Sandia designs better batteries for grid-scale energy storage

Photo, posted March 14, 2021, courtesy of Michael Mueller via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Red Hot Chili Solar Panels | Earth Wise

April 9, 2021 By EarthWise Leave a Comment

The majority of solar panels in use today are made from either single-crystal or polycrystalline silicon, the same stuff used to make the ubiquitous chips in computers, cell phones, and countless other devices. In addition, a growing fraction of solar panels utilize thin-film technology, which offers cost and flexibility advantages.

Monocrystal silicon still provides the highest efficiency and longest lifespan in commercially available panels, but the lower costs and some other features of thin-film solar panels are growing that market over time.

More recently, perovskite solar cell technology has been a source of great interest in the research community. Perovskites are a class of minerals with a specific crystalline structure that already have uses in various applications. As a solar cell material, perovskites offer the potential for converting more sunlight to electricity, being manufactured far more cheaply using no exotic or expensive materials, being more defect-tolerant, as well as a having number of other advantages. They also have the potential for having very high efficiency.

Recently, a group of researchers in China and Sweden published results of studies demonstrating that the addition of a novel ingredient has increased the efficiency of perovskite solar cells to nearly 22%, which is better than most commercial silicon solar cells. The ingredient is capsaicin, the chemical that gives chili peppers their spicy sting. Adding capsaicin expands the grains that make up the active material of the solar cell, allowing the more effective transport of electricity.

Why did the researchers think of adding the active ingredient of hot peppers to a solar cell in the first place? So far, they aren’t saying.

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Solar panels capture more sunlight with capsaicin – the chemical that makes chili peppers spicy

Photo, posted August 16, 2019, courtesy of Pedro via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Rare Earths From Mining Waste

May 3, 2019 By EarthWise Leave a Comment

The 17 rare earth elements have become important parts of much of modern technology. Despite their name, most of these elements are relatively plentiful in the earth’s crust, but because of their geochemical properties they are typically dispersed and not often found concentrated in minerals. As a result, economically exploitable ore deposits are uncommon. There are no significant sources in the U.S.

Rare earths play important roles in high-performance magnets, electric motors in vehicles, wind turbines, microphones and speakers, and in portable electronics like cell phones. As these applications become ever larger, the need for additional sources of rare earths increases.

Researchers at Idaho National Laboratory and Rutgers University have studied a method for extracting rare-earth elements from mining waste that could greatly increase the world’s supply of these valuable materials.

It turns out that large amounts of rare earths exist in phosphogypsum, a waste product from producing phosphoric acid from phosphate rock. The U.S. alone mined 28 million tons of phosphate rock in 2017. (Phosphoric acid is used in the production of fertilizers and other products).

The researchers estimate that more than a billion tons of phosphogypsum waste sits in piles at storage sites across the U.S. alone. World-wide, about 100,000 tons of rare earth elements per year end up in phosphogypsum waste. This compares to the total current world-wide production of rare earth oxides of 126,000 tons.

The researchers studied methods for extracting the elements from the waste. A method utilizing a common environmental bacterium showed great promise.

There are concerns about residual radioactivity and other environmental issues in dealing with the waste material, but the world’s supply of rare earth elements might become much greater based on this research.

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Critical Materials: Researchers Eye Huge Supply of Rare-Earth Elements from Mining Waste

Photo, posted June 19, 2015, courtesy of David Stanley via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Transparent Solar Panels

December 6, 2017 By EarthWise Leave a Comment

It is now commonplace to see solar panels on the rooftops of homes and businesses. There are more than a million solar homes in the US alone. But a new generation of see-through solar technology has the potential to also turn the windows of buildings and cars, as well as other glass-coated objects, into electricity generators.