There is a story told about miners who found copper cans in garbage dumps in the early days of mining. Wastewater from copper mining was flowing through his land, he said, and turned the steel cans into copper.
The story may be apocryphal, but the process is authentic and is called cementation. Montana Resource, a mining company that took over from the Anaconda Copper Company, still uses this alchemy trick in the process of the Continental Pitmine in Butte, Mont.
Next to the mine is the Berkeley Pit, which is filled with 50 billion gallons of highly acidic, toxic brews. Montana Resource allows liquids to pipe from the pits and cascade them into piles of iron. Iron becomes copper and is collected for production.
Although there have been a long time methods of removing metals from water, in recent years, global scrambling of metals, which has been important for manufacturing and technological advances, has produced a new generation of extraction techniques and processes.
One of the mineral-rich sources researchers are focusing on is wastewater, such as salt water from desalinated plants, oil and gas fracking water, and wastewater from mining. Researchers at Oregon State University estimate that only salt water from desalinated plants contains about $2.2 trillion in metal.
“Water is a 21st century mineral body,” said Peter S. Fisuke, director of the National Water Innovation Alliance in California at the Department of Energy's Lawrence Berkeley National Laboratory. “Currently, technology allows us to pick up piles of wastewater waste and choose valuable items.”
Research into the extraction of rare earths, a set of metal elements from waste, is widespread as their need increases significantly. For example, researchers at Indiana Geosurvey at Indiana University are studying the possibility of mining rare earth coal waste, such as fly ash and coal tails. Researchers at the University of Texas at Austin have created membranes that mimic natural membranes to separate rare earths from waste.
Mining wastewater is not only economical and faster than starting a new mine, but also cleaner.
The large waterborne awards in the pit next to Butte include two light rare earth elements (REE), neodymium and praseodymium. They are essential for small and powerful magnets, medical technology, and for defensive purposes such as precision guided missiles and satellites in electric vehicles. The single F-35 Fighter Jet uses 900 pounds of rare earth metal.
“We are turning huge responsibility into something that contributes to defense,” said Mark Thompson, vice president of environmental affairs at Montana Resources. “There's a few high levels of metallurgy happening here. The real egghead stuff.”
This is an important time to study domestic production of rare earths. Not only is the US far behind China, but President Trump's trade war has threatened the Chinese president to further limit rare earth mineral exports as a result of Trump's tariffs. Key mineral security program experts at the Center for Strategic and International Research say the big gap will allow China to expand its defense capabilities much faster than the US.
Both Greenland and Ukraine are largely the focus of the Trump administration's attention. Because countries have important rare earth sediments.
Trump has also just ordered the government to move to mine most of the seabed, including international waters, for the wealth of its minerals.
There are 17 different types of metals known as rare earths, all of which have been discovered in the Berkeley Pit. They are not uncommon in prevalence, but they are often called because they are scattered in small concentrations.
Rare Earths are classified into two types: heavy and light. Heavy rare earths such as dysprosium, terbium and yttrium have a larger atomic mass, usually more rare, meaning they are sold in small quantities and are prone to shortages. In contrast, photometals have a low atomic mass.
The drainage of acid mines is a highly toxic contaminant that is produced when sulfur-containing pyrite in rocks is exposed to oxygen and water during mining. The drainage then forms by oxidizing sulfuric acid and poison channels. It is one of the nation's biggest environmental issues, with tens of thousands of abandoned mines polluting 12,000 miles of streams.
However, acids dissolve zinc, copper, rare earths and other minerals from rocks in water, providing an opportunity to extract appropriate techniques that have not been present until recently.
Paul Ziemkievich, director of the Water Institute at West Virginia University, has been studying Bute's pitwater for 25 years. He and the team at the chemical engineering company Virginia Tech and L3 Process Development have developed a method to extract critical metals from acid mine drainage in West Virginia coal mines, the same process used in Butte. The large, densely woven plastic bags are filled with mud-like sludge from the water treatment plant. The water penetrates slowly and leaves about 1-2% rare earth preconcentrate, which needs to be further refined using chemical processes. The final step in the patented process is extraction with a solvent that creates pure rare earth elements.
“One of the great things about acid mine drainage is that the concentrates we get are especially rich in heavy rare earths,” said Dr. Ziemkiewicz. “Light things aren't that valuable.”
The Butte project is waiting for words about the $75 million Department of Defense grant, and is the final step needed to improve rare earth enrichment and start full-scale production.
Zinc is also abundant in acid ore drainage mixes here and is important as a payment method for the process as it gets you a higher price. Nickel and cobalt are also extracted.
Rare earth elements are in great demand, but China produces a majority, manipulates prices to keep them low and forces competition. That's why the Department of Defense funds many work on rare earth elements and other metals. The United States has only one operational rare earth mine in Mountain Pass, California. It produces around 15% of the global supply of rare earths.
The Berkeley Pit has been a blessed pain since 1982, when Anaconda copper companies closed their open pit mines and turned off the pump and filled the water. Water is so acidic from the drainage of acidic mines that when tens of thousands of snow geese moved and flew in 2016, many landed on the surface and quickly became poisoned. Approximately 3,000 birds have died.
The Atlantic Richfield Company and Montana Resources are necessary for permanently treating pitwater to prevent it from reaching levels that could pollute the area's groundwater. (Montana Resources mines the continental pit next to the Berkeley Pit.) Clean Water Act requires businesses to handle the drainage of acid mines. Adding another level of treatment to a horseshoe bend plant here is less expensive than building something new, and can offset the cost of treatment and also increase profits.
There have been dozens of research efforts to release suspended metals from the water. Thompson displayed a map showing where radiation was emitted from Butte and where water samples were sent to research facilities around the country. However, the ongoing metal production process is the first process to prove economical.
The wealth of mineral soups here has been known for decades, but the way they extract was elusive until Dr. Diemkievich's team developed new methods. He produces rare earths in two coal mines in West Virginia, and the drainage of acid mines is a problem. Each mine produces 4 tons of rare earths a year.
However, Berkeley Pits are expected to produce 40 tons per year due to much more abundant rare earth concentrations in solution and high water content. Dr. Ziemkiewicz believes that when used in other mines, this process can ultimately provide the import of almost all of the rare earth elements needed for defensive purposes.
However, some estimates show that rare earth demand could increase by up to 600% in the coming decades.
Lawrence Berkeley's labs are studying water filtration-related technologies, particularly experiments, to improve membranes, in their global efforts to clean water, clean important minerals and produce important minerals. It operates a particle accelerator called an advanced light source. This creates very bright X-ray light that allows scientists to study various films at the atomic scale.
The lab worked with external researchers to create a new generation of filters called nanosponges, designed to trap single target molecules such as lithium.
“It's an atom catcher's mitt,” said Adam Uliana, chief executive of Chemfinity, a Brooklyn company that studies the use of nanosponges to clean many different types of waste. “It catches only one type of metal.”
Lithium, cobalt and magnesium are important minerals, in addition to rare earths that have attracted considerable attention from researchers.
Ion exchange, a proven technology for removing metals from water and removing contamination, is attracting interest. Lilac Solutions, a startup in Oakland, California, has developed the specialized resin beads needed to extract lithium from brine by ion exchange and has planned to start its first production facility in Great Salt Lake, Utah.
The company's technology pumps brine through an ion exchange filter, extracts minerals, and returns water to its source. The company's president, David Snyducker, said there were few environmental disruptions. If proven to work on a large scale, it could revolutionize lithium extraction, reducing or eliminating the need for underground mines and open pits.
Maglathea Metal is an Auckland startup that makes magnesium ingots from the salty salty water left after the seawater has been desalinated. The company allows the brine that leaves the salt of magnesium chloride to be dried. An off-peak renewable energy-enabled current heats the solution and separates the salt from molten magnesium.
Its CEO Alex Grant said the process is very clean, but it has not yet been used in the production of magnesium. The Department of Defense funds much of its work.
China produces 90% of the world's magnesium. Metals are smelted with what is called the Pidgeon process. It is heated to about 2,000 degrees by coal-fired ki, which is highly contaminated and carbon-intensive. Dr. Fisuke expects more innovation.
“Three vectors are converging,” he said. “The value of some of these important materials is increasing. The cost of traditional mining and extraction is increasing, and security in international suppliers, especially Russia and China, is decreasing.”
