Magnetic nanoparticles to be used to extract lithium from brines in the US PNNL researchers developed a technology that is able to extract battery metals from geothermal fluids. (Image courtesy of Pacific Northwest National Laboratory) A technology that uses magnetic nanoparticles to capture valuable materials from brines is being launched today by its developer, the US Department of Energy’s Pacific Northwest National Laboratory, and its licensee, Moselle Technologies. According to these organizations, the core nanoparticle in the development consists of a form of iron oxide better known as magnetite. This core particle is used to anchor an adsorbent shell that selectively binds the compounds of interest.