STUDIES OF THE BEHAVIOR OF THE TBP-KEROSENE SOLVENT IN URANIUM REFINING: DEGRADATION OF THE KEROSENE DILUENT

摘要

Extensive studies have been conducted of kerosene-type diluents for the tri-n-butyl phosphate (TBP)-kerosene solvent used in uranium extraction. Wide variations have been shown in the paraffinic, isoparaffinic, aromatic, and olefinic hydrocarbon contents of these diluents. Such diluents have been shown to be unstable in the presence of high nitric acid concentrations, and in the presence of small amounts of nitrous acid. . This instability is primarily a function of the non-paraffinic hydrocarbon content of the diluent and of the nitrous acid con¬centration of the contacting medium. Degradation of a diluent has been shown to discolor a diluent, increase its density and viscosity, and influence uranium distribution during re-extraction operations. Solvent treatment with Na2CO3, followed by H2O and nitric acid washes, has been shown to be only partially effective in removing diluent degradation products.