Extracting Uranium from oceans offers a mixed bag of possibilities

Oak Ridge National Labs (ORNL) yesterday announced a new technique for efficiently harvesting uranium from the ocean. This raises the possibility that Uranium supplies will be much deeper and longer lasting than previously thought. For the environmentally minded it raises a quandary, in that nuclear energy is one way of avoiding fossil fuels, but there are radiation risks galore.

The technology, called HiCap Adsorbents, was co-developed by ORNL and Hills Inc. and is a low cost reusable material that can remove metals from aqueous environments. That’s a big word way of saying it is a filter that can remove metals, such as Uranium, from the ocean or other bodies of water. The high-surface-area polyethylene fibers in HiCap can rapidly, selectively and economically extract valuable and precious dissolved metals from water.

“We have shown that our adsorbents can extract five to seven times more uranium at uptake rates seven times faster than the world’s best adsorbents,” said Chris Janke, one of the inventors and a member of ORNL’s Materials Science and Technology Division.

According to the ORNL the worlds oceans are estimated to contain 4.5 billion tons of Uranium. The oceans also contain a large variety of other dissolved materials that would be valuable to manufacturers.

Adsorbent materials have been an subject of research around the world. What makes the ORNL HiCap material different is “the adsorbents are made from small diameter, round or non-round fibers with high surface areas and excellent mechanical properties”.

“Our HiCap adsorbents are made by subjecting high-surface area polyethylene fibers to ionizing radiation, then reacting these pre-irradiated fibers with chemical compounds that have a high affinity for selected metals,” Janke said.

Placing the adsorbent material in water, the targeted material is trapped into the adsorbent. After removing the adsorbent material from the water, it is given an acid treatment to extract the trapped material, and then it can be reused again after conditioning with potassium hydroxide.

The new design cuts the production cost of extracting Uranium from ocean water from $1232 to $660 per kilogram. This is still five times more expensive than Uranium mined from the Earth. “A sharp spike in uranium prices in 2007 had many people scared in terms of the sustainability of the nuclear industry,” ORNL chemical scientist Sheng Dai says. “That was what spurred the [Department of Energy] to revisit developing the technology.”

There are several ways to ponder what this means.

The news coverage of this material is focusing on its ability to extract Uranium. This will lead to greater availability of Uranium, encouraging the development of more nuclear power stations. As we noted above doing so could reduce the use of fossil fuels which is a good and proper goal, but there is the huge spectre of more nuclear accidents and radiation exposure.

It would appear this material could be used to target other materials. For example there are concerns over supplies of lithium, or of rare earth metals, or various other minerals, some of which are present in ocean water. Could this material be tailored to target extraction of those materials from the ocean, providing a source of raw materials that is independent of digging rocks out of the ground? If so it could reduce the amount of hard rock mining operations around the world.

Maybe the material could be used in environmental mitigation, in that there are sites poisoned by releases of toxic metals into the ocean.

But what if corporations so efficiently mine the oceans certain metals that it actually affects the chemical balance of the ocean? The existing chemical balance in the ocean is vital to the food chain, and changing that balance would clearly have some effect on the living things in the ocean. Do “we” even have a clue about the potential impact?

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About David Herron

David Herron is a writer and software engineer living in Silicon Valley. He primarily writes about electric vehicles, clean energy systems, climate change, peak oil and related issues. When not writing he indulges in software projects and is sometimes employed as a software engineer. David has written for sites like PlugInCars and TorqueNews, and worked for companies like Sun Microsystems and Yahoo.