New treatment of liquid effluents of the Lodeve plant

The Lodeve uranium plant was based on an alkaline process in autoclave at a 6 bar oxygen pressure and a temperature of 140 deg C. It produced 12 900 tons of uranium from 1981 to 1997. After the shut down of the plant, it has been necessary to decontaminate the mine site; for this purpose, vat leaching has been performed and the water treated by the fixation of the uranium contained in ion-exchange resins. The resin was disposed in containers and eluted with sulphuric acid, first at the Jouac plant and, after its closure at the Comurhex plant at Malvesi, near Narbonne. In the latter case, the elution process has been modified to meet the special environmental conditions of the site; in that purpose, new laboratory studies were performed at the SEPA laboratories near Limoges. 5,8 tonnes of uranium in 2001, 6,8 in 2002, 9,1 in 2003, were recovered. The paper gives in full detail the various flow-sheets as well as the numerous tests that have been performed. (author)