Oxidants for uranium leaching
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Date
2007-05-24
Journal Title
Journal ISSN
Volume Title
Publisher
ALTA Metallurgical Services
Abstract
Most uranium ores are leached with sulfuric acid under oxidising conditions. This paper reviews the oxidants that have been traditionally used in uranium leaching and discusses their merits in the context of overallow sheet considerations. Options for alternative oxidants are also discussed. In acid leaching, ferric ion (Fey) in solution oxidises insoluble uranium(IV) to soluble uranium(VI). Though ferric ion may be added directly, usually an oxidant is added to the circuit to convert ferrous ion to ferric ion in the liquor so that leaching can continue. The most common oxidants are pyrolusite and sodium chlorate. Pyrolusite is relatively cheap but introduces manganese ions into the liquor and consumes twice as much acid as sodium chlorate. Sodium chlorate is a slow reacting oxidant at low temperatures and acidities, and introduces chloride into the leach liquor. Caro ’s acid, HZSO5, is a non-polluting reagent that was used successfully at the Nabarlek uranium mine, and provided very good control of oxidising conditions. Other oxidants that are now being considered to overcome the disadvantages of pyrolusite and sodium chlorate are oxygen, hydrogen peroxide and SO/O2. Some
performance data for these oxidants are presented. © The Authors
Description
Physical copy held by ANSTO Library at DDC 669.2931/5
Keywords
Uranium, Leaching, Ore processing, Sulfuric acid, Oxidation, Iron compounds, Manganese ions, Temperature range 0065-0273 K, Sodium chlorides, Hydrogen peroxide, Oxygen
Citation
Ho, E., & Ring, R. (2007). Oxidants for uranium leaching. Paper presented to the ALTA 2007 Uranium Conference, Rendezvous Observation City Hotel, Perth, Australia, May-24-25 2007.