Researchers at Stanford University in California have developed a new way of extracting uranium from seawater. The team has developed a technique that improves the capacity, rate and reusability of materials that harvest uranium from seawater.
In the past, researchers at the Oak Ridge national laboratory in the US demonstrated a material that could pull uranium, in the form of uranyl ions, out of the water like a sponge. It did so with the help of plastic fibres coated in a chemical compound called amidoxime, which attracts the ions and holds them to the surface of the fibre. Once the fibre is saturated, the uranyl can be released by chemically treating the plastic, and then refined for use in reactors. Using a similar system, the Stanford researchers created their own conductive fibre made of carbon and amidoxime, which allowed them to send jolts of electricity through the material to attract more uranyl to each strand.
The method improved on the previous system in three key areas: the capacity for how much uranyl the fibres can hold, the speed of ion capture, and how many times each strand can be reused. “For much of this century, some fraction of our electricity will need to come from sources that we can turn on and off,” said Steven Chu, co-author of the study. “I believe nuclear power should be part of that mix, and assuring access to uranium is part of the solution to carbon-free energy.”
