Uranium recovery from wet-process phosphoric acid with octylphenyl acid phosphate. Progress report

Technical Report · Tue Jan 01 00:00:00 EST 1980

DOI:https://doi.org/10.2172/5719849· OSTI ID:5719849

Arnold, W. D.; McKamey, D. R.; Baes, C. F.

Studies were continued of a process for recovering uranium from wet-process phosphoric acid with octylphenyl acid phosphate (OPAP), a mixture of mono- and dioctylphenyl phosphoric acids. The mixture contained at least nine impurities, the principal one being octyl phenol, and also material that readily hydrolyzed to octyl phenol and orthophosphoric acid. The combination of mono- and dioctylphenyl phosphoric acids was the principal uranium extractant, but some of the impurities also extracted uranium. Hydrolysis of the extractant had little effect on uranium extraction, as did the presence of moderate concentrations of octyl phenol and trioctylphenyl phosphate. Diluent choice among refined kerosenes, naphthenic mixtures, and paraffinic hydrocarbons also had little effect on uranium extraction, but extraction was much lower when an aromatic diluent was used. Purified OPAP fractions were sparingly soluble in aliphatic hydrocarbon diluents. The solubility was increased by the presence of impurities such as octyl phenol, and by the addition of water or an acidic solution to the extractant-diluent mixture. In continuous stability tests, extractant loss by distribution to the aqueous phase was much less to wet-process phosphoric acid than to reagent grade acid. Uranium recovery from wet-process acid decreased steadily because of the combined effects of extractant poisoning and precipitation of the extractant as a complex with ferric iron. Unaccountable losses of organic phase volume occurred in the continuous tests. While attempts to recover the lost organic phase were unsuccessful, the test results indicate it was not lost by entrainment or dissolution in the phosphoric acid solutions. 21 figures, 8 tables.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5719849
• Report Number(s): ORNL/TM-7182; TRN: 80-004378
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
URANIUM
SOLVENT EXTRACTION
HYDROLYSIS
IMPURITIES
LOSSES
ORGANIC SOLVENTS
PHOSPHORIC ACID
PHOSPHORIC ACID ESTERS
RECOVERY
SOLUBILITY
STABILITY
ACTINIDES
CHEMICAL REACTIONS
DECOMPOSITION
ELEMENTS
ESTERS
EXTRACTION
HYDROGEN COMPOUNDS
INORGANIC ACIDS
LYSIS
METALS
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
SEPARATION PROCESSES
SOLVENTS
SOLVOLYSIS
050400* - Nuclear Fuels- Feed Processing