Contaminated bulk material cleaning process for rubble and excavated earth contaminated with thorium and other radio nuclides

摘要

Thorium-contaminated bulk material is cleaned by suspending in water, sedimenting clean coarse particles, separating the fine suspension and separating the contaminated fines. Thorium-contaminated bulk material is cleaned by subjecting its aqueous suspension to (a) high shear force flow classification (41) to cause sedimentation of the coarse particles; (b) separation (42) of the fine suspension (9) of contaminated ultra-fine particles from the sediment while preventing gravity sedimentation onto the coarse particles by application of a transverse force; (c) separation (43) of the fines from the suspension; and (d) withdrawal of the heavy fraction of the bulk material as cleaned wet material (7). An Independent claim is also included for a plant for carrying out the above process.