Separation of lanthanum from a rare earth chloride mixture using a multistage mixer-settler extractor
- Iowa State Univ., Ames, IA (United States)
A pilot plant scale, multistage box-type mixer-settler extractor was operated to demonstrate the feasibility of separating lanthanum from a mixture of rare earth chlorides of monazite origin using di(2-ethylhexyl) phosphoric acid in Amsco Odorless Mineral Spirits for the organic solvent and dilute HC1 as the aqueous scrub solution. Using 0.5 M D2EHPA as the organic solvent, 0.1 M HC1 as the aqueous scrub solution and 2.6 M REC1 3 as the feed, steady state with respect to the rare earth concentration was achieved in both 10 and 20-stage mixer settler extractors. Several runs were made to find the operating conditions necessary to achieve a 95% pure lanthanum raffinate product from a feed containing 45.6% lanthanum, 10.0% cerium, 30.5% neodymium, 3.6% samarium, 8.0% praseodymium, and 2.4% gadolinium. Using a 20-stage extractor, operating conditions were found which produced a 97% lanthanum raffinate product with a 60% lanthanum recovery. On a cerium free basis this corresponds to a 99% lanthanum product. A study of the dynamics of the system was also made using the 10-stage extractor, 0.5 M. D2EHPA, 0.1 M HC1, and 2.7 M REC13. Base operating conditions were chosen which produced an approximately 88 mole % lanthanum raffinate product. Once steady state was reached, intentional upsets of varying degree were made in the individual flow rates and interface positions to test their effect on the raffinate product concentration and on the operation of the mixer-settler. Six runs were made in this manner, each one testing the effect of a single variable. The relative importance of the various variables on the steady state concentration of the raffinate product was to be determined. It was found that the REC13 flow rate is by far the most important variable to be controlled and if steady state is to be maintained, even small fluctuations in the RECl3 flow rate cannot be tolerated. The other most important variables to control are, in order of importance; the HC1 flow rate, the D2EHPA flow rate, and the settler interface positions. (author)
- Research Organization:
- Ames Lab., Ames, IA (United States)
- Sponsoring Organization:
- US Atomic Energy Commission (AEC)
- DOE Contract Number:
- W-7405-ENG-82
- NSA Number:
- NSA-25-002310
- OSTI ID:
- 4106313
- Report Number(s):
- IS-T-411
- Resource Relation:
- Other Information: Thesis. UNCL. Orig. Receipt Date: 31-DEC-71
- Country of Publication:
- United States
- Language:
- English
Similar Records
Scale-up of a mixer-settler extractor using a unit operations approach
Validation of the generic TRUEX model using data from TRUEX demonstrations with actual high-level waste
Related Subjects
CHLORIDES
DEHPA
LABORATORY EQUIPMENT
LANTHANUM
MIXING
RARE EARTHS
SEPARATION PROCESSES
LANTHANUM/separation from rare earth chlorides by solvent extraction using D2EHPA and multistage mixer-settler extractor
RARE EARTH CHLORIDES/separation of lanthanum from
by solvent extracton using D2EHPA and multistage mixer-settler extractor