Continuous ash extraction process

摘要

In the process for recovering radioactive metal from solid metal oxides, the metal oxide is treated by a co-current flow of a first acid solution in a first contactor to form partially reacted oxides and a metal-containing solution. The solution is drawn off and the partially reacted oxides are passed through a countercurrent flow of a second acid solution in a second contactor to form reaction residues and a second metal-containing solution. The second solution is drawn off and the residues are passed through a countercurrent flow of wash water and then separated from the wash water. Also claimed is an apparatus for recovering radioactive metals from solid metal oxides consisting of three contactors operating the process as described above. Also claimed is an apparatus for recovering radioactive metal from metal oxides consisting of three contactors with feed and discharge means for solids, acids and water. The first contactor should be horizontal so that gases are vented from the co-current flow of oxides and acid. The extractant may be 20-30% by weight nitric acid. Heat should be applied to the first and second contactors to maintain the acid solution at about 130-170[deg] F. The first and second metal containing solutions may contain fines which may be separated. A centrifuge may be used to separate the fines suspended in the radioactive metal-containing solution.