The Extraction of Europium from Monazite Residues and the Preparation of Pure Europium Compounds

Abstract

205-210 dec. (C4HI0NBr)n 52.63 52.56 CiHs 10 31-32 2 7.0 195-199 (C6H12NBr)" 48.19 47.00 »-C,H, 8 37-38 3 1 (C6H,4NBr)" 44.44 43.31 ft-C4H9 5.2 3.6 100-120 (C6H,«NBr)" 41.23 41.33 t-CjHg 6.4 4.4 (CrHuNBr), 41.23 41.30 precipitated with dry ether, the total bromine remained approximately constant at 51.96%, but the bromide ion fell to 43.38%. Further attempts to purify the mixture did not lead to any definite product.A sample of the free polymeric tertiary amine was prepared from the polymeric salt obtained from 7-bromopropylmethylamine. The salt used in this experiment contained 50.3% bromine, and 49.07% bromide ion. A solution of 5 g. of this salt in water was treated with an excess of silver oxide, and then the solution was filtered. The

Studies on europium separation from a middle rare earth concentrate by in situ zinc reduction technique

“…It was reported by McCoy [21], that the hot magnesium sulphate solution gave rise to the ␤-form of europous sulphate, rather than the ␣-form. This is desirable as the former is less soluble and much denser than the latter.…”

“…Zinc powder has been widely used with success for achieving the reduction process of europium [21,24,33,34]. Despite the good results obtained with zinc powder over the other two types, it suffers from the difficulty in separating the unreacted zinc as a result of its small grain size.…”

“…This concentration is 2.5 times the stiochiometric amount of ammonium sulphate. In addition, McCoy [21], in his early work utilized two times the stiochiometric amount of magnesium sulphate to precipitate about 250 g europium oxide. Otto [33], employed a stiochiometric amount of one to precipitate a much larger europium content of 450 g. It seems sound that, as the europium concentration (content) in the feed solution increases, the less stiochiometric amount of the precipitating gent will be needed to carry out the precipitation reaction.…”

“…Several techniques based on electrochemical reduction [8][9][10][11][12], photochemical reduction [13][14][15][16], radiochemical reduction [17,18], and chemical reduction using zinc [19][20][21][22][23], zinc amalgam [7,21,[24][25][26] have been used for the separation of europium from other rare earth elements. Separation methods based on chemical reduction are the most utilized and applicable one.…”

Neutron Capture Experiments on Unstable Nuclei

“…Since the reductant is contained within a column, contaminants introduced to the sample during reduction are kept to a minimum. 7,105 various metal (Eu, Zn, Na) amalgams …”