Purification Of Rare Earth Elements Research Articles

PURIFICATION OF YTTRIUM BY HIGH-SPEED COUNTERCURRENT CHROMATOGRAPHY

Separation of rare earth elements has been studied by high– speed countercurrent chromatography (CCC) employing 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester in toluene as a stationary phase. The CCC method was applied to purification of rare earth elements in a wide range of concentrations. High-purity yttrium was chromatographically isolated by removing micro amounts of similar lanthanoid elements such as holmium and erbium.

Preconcentration and Purification of Rare Earth Elements in Natural Waters Using Silica-Immobilized 8-Hydroxyquinoline and a Supported Organophosphorus Extractant

8-Hydroxyquinoline immobilized on silica gel (silica3HQ) and RE-Spec, a supported organophosphorus extractant, were used to preconcentrate and purify rare earth elements (REEs) from natural waters prior to their determination by isotopedilution inductively coupled plasma mass spectrometry (IDICPMS). Preconcentration onto silica-8HQ is applicable to a wide range of trace metals, making it suitable for multielement ID-ICPMS studies. The silica-8HQ, RE-Spec technique concentrates REEs from 1 L or less of water into 1 mL of salt-free 0.1% nitric acid. The technique is rapid and has high REE yields (>80%) and low REE blanks ( 4 bg of Ba. We report a preconcentration and purification chemistry for the determination of rare earth elements (REEs) in natural waters by isotope-dilution inductively coupled plasma mass spectrometry (ID-ICPMS). The sensitivity and multielement measurement capability of the ICPMS are ideally suited to the determination of dissolved metals, which are present at extremely low concentrations in natural waters. Furthermore, the ability to measure isotopic ratios accurately at the 0.1-1 %

Studies on selective separation of Sc(III) from rare earth elements on selective ion-exchangers

Results of studies on the separation of microquantities of scandium(III) from macroquantities of rare earth elements, as well as some transition and representative elements, on selective ion-exchangers of different types are given. The most effective ion-exchangers for the purification of rare earth elements from Sc(III) by frontal analysis are: phosphonic - Duolite ES-63, (Dia - Prosim France), aminophosphonic - Duolite ES-467 (Dia - Prosim France) and cellulose phosphate - Serva P (Serva F.R.G.). Using these ion-exchanger, Sc(III) can be selectively separated from Y(III), La(III) or Ln(III) from their salt solutions of concentrations up to 500 g/l and acidity to 6 M HCl.

溶媒抽出による希土類元素の分離と精製

溶媒抽出による希土類元素の分離と精製

SEPARATION OP RARE EARTH - POLYALZDTOCARBOXYLIC ACIDS COMPLEXES OK VARIOUS TYPES OF ANION-EXCHANGERS

ABSTRACT There has been shown the application of frontal analysis in purification of rare earth elements in complexes with EDTA on anion exchanger in the EDTA form and with IMDA on anion exchanger as an iminodi-acetate form in macro - microcomponent systems. The presented method with EDTA is effective in purification of yttrium from neodymium and terbium, lanthanum from neodymium, erbium from dysprosium and gadolinium from europium but with IMDA in purification of yttrium from heavy lanthanides (especially from ytterbium) and neodymium from yttrium. Out of the examined standard anion-exchangers Dowex in the system with EDTA Dowex 2 of functional benzyldimethylhydroxyethylammonium groups proved to be the moat effective in purification of yttrium from neodymium. The obtained results confirm the hypothesis that the complex structure is decisive in separation of ra-re-earth - EDTA complexes on anion-exchangers in the EDTA form but in the case of rare-earth-IMDA complexes the difference in their stability cons...

分別結晶法による希土類元素の分離精製(その2)--分別結晶法における晶出条件--

分別結晶法による希土類元素の分離精製(その2)--分別結晶法における晶出条件--

The Seperation and Purification of Rare Earth Elements from Monazite (I)

Abstract (1) The rare earths, free from thorium, could be separated as the earths sulphate double compound (yield 93%). (2) The method of separating thorium from the filtrate, which was obtained by separating about 63% of rare earths salt from the extracted solution, gives better result than a method of direct fractional precipitation from the extracted solution. (3) Cerium can be separated from a solution as rare earths ammonium double compound with a purity of 92–96% (yield 70–75%). (4) In the separation of cerium, a maximum point of purity is obtained when sufficient quantity of ammonia is added just to remove the colour of Ce ion from the solution. The purity and yield of cerium is not strictly in an inverse proportion, but a point of maximum purity of precipitate is obtained when a certain definite amount of ammonia is added.