Magnetic separation to remove actinides from soils

Magnetic Separation is a physical separation process that segregates materials in a mixture on the basis of magnetic susceptibility. Because all actinides and their compounds and fission products are paramagnetic and most host materials such as water, graphite, soil, and sand are diamagnetic, magnetic separation methods can be used to extract the actinides from these hosts, concentrating the toxic materials into a low volume waste stream. The technology relies only on physical properties, and therefore separations can be achieved while producing little or no secondary waste. The High Gradient Magnetic Separation (HGMS) is being used at Los Alamos for applications to soil decontamination, liquid waste treatment, underground storage tank waste treatment and chemical processing residue concentration. HGMS involves passing a slurry through a magnetized volume and is used to separate solids from other solids, liquids, or gases. It is most effective on small particles (90 microns and smaller), and is complementary to other separation technologies. Results with non radioactive surrogates and radioactive materials show that over 99% extraction of the paramagnetic components can be achieved