PURIFICATION OF PROMETHIUM BY LIQUID-LIQUID EXTRACTION

Technical Report · Fri Feb 12 04:00:00 EST 1960

DOI:https://doi.org/10.2172/4175865· OSTI ID:4175865

Weaver, B.; Kappelmann, F. A.

A process was developed for separating promethium from raixed fisBion product rare earths by continuous multistage conntercurrent extraction with 100% tri-nbutylphosphste from nitric acid of 12 N or higher concentration. Distribution coefficients at 12 N acidity for aecdamium. promethium. and samarium are 0.43. 0.82, and 1.55, respectively. Single-stage separation factors of 1.9 between successive elements can be maintained throughout the system to give separations dependent only on the number of stages. Extracted values can be recovered from the organic solution by stripping with a smaller volume of dilute nitric acid. A flowsheet for purification of promethium includes one cycle for separation of promethium from neodymum and lighter elements and a secondycle for removal of samarium and heavier elements. Each cycle consists of a series of countercurrent partitioning stages. followed by stripping stages and an evaporator. With 20 stages in the first cycle and 34 stages in the second, a 90% yield of promethium with a purity of 83% can be obtained from a typical mixture of fission product rare earths, assuming essentially perfect mechanical efficiency. An increase to 34 stages in the first cycle would permit a 93% yield of 99% promethium. (auth)

• Research Organization: Oak Ridge National Lab., Tenn.
• DOE Contract Number: W-7405-ENG-26
• NSA Number: NSA-14-007451
• OSTI ID: 4175865
• Report Number(s): ORNL-2863
• Country of Publication: United States
• Language: English

Related Subjects

ACIDITY
BUTYL PHOSPHATES
CHEMISTRY
COUNTER CURRENT
DIAGRAMS
DISTRIBUTION
FISSION PRODUCTS
IMPURITIES
LIQUIDS
NEODYMIUM
NITRIC ACID
PLANNING
PROMETHIUM
RARE EARTHS
RECOVERY
SAMARIUM
SEPARATION PROCESSES
SOLVENT EXTRACTION