together with the precipitation of the rare earth oxinates with the lanthanum carrier is a t least 97% (3). Because the recovery in either the double oxalate or fluoride precipitation was essentially loo%, the over-all recovery of the rare earths should be about 97%. This value was checked bv analyzing duplicate 10-gram samples of beryllium to which was added europium-152-154 after dissolution. An average 98% recovery of the tracer activity was found in the final oxide residue. With larger 28-gram samples, the recovery was 96%. K i t h 40-gram samples of magnesium, the recovery was 96%. Tracer recovery testq were also carried out on duplicate &gram samples of zirconium, titanium, uranium, and stainless steel. In the case of uranium, the blank activity of any gammaemitters in the final residue was determined first by carrying an identical sample through the procedure without the tracer addition. The blank was small enough to be ignored. In each case, the recovery of the tracer in the final residues for the spectrographic analysis was a t least 97%. The separation was further checked by analyzing samples both with and ~ i t h o u the t addition of 25-y quantities of samarium, gadolinium, dysprosium, and erbium (Table 11). The rare earth residues generally n-eigh about 2 mg., which includes 1.2 mg. of linthanuni oxide. Traces of calcium, magnesium, aluminum, bergllium, silicon, and thorium are frequently found in addition to the rare earths. Further purification can be carried out if desired (3).
Table
I.
Recovery of Tracer under Various Conditions
Precipitat,ing Conditions Saniple Tho48% HF, C2H204, NHdF, rium(IV), Wt., Sample Grams ml . grams grams mg. 100 Zr 5 Excessa .. 100 5 Excessa 3 100 4’ . . Excessa 8.5 .. 50 Ti 4 Excessa 50 3 5 Excessa 100 U02(N03)2,6H20 10 5 .. 100 10 5 .* 3 100 Stainless steel 310 5 .. 3 5 10 100 .. 100 5 10 .. 3 a About 5 ml. in excess. b Identical result obtained in triplicate tests. Table 11.
Be Zr
10
U
5 5 5
7
Ti
Stainless steel 310
%
61, 66
99*
94 99b 92 995 43, 70 91, 98 99*
Recovery of Rare Earths Added to Metal Samples
Sample Wt., Grams
Sample
EuIs2-16‘ in Ppt.,
Sm 30 24 25 28 26
ACKNOWLEDGMENT
Acknowledgment is given to the New Brunswick Laboratory Spectrographic Analysis Section for the Spectrographic determinations. LITERATURE CITED
(1) Gordon, Louis, Firsching, F. H., Shaver, K. J., ANAL. CHEM.28, 1476 (1956). (2) Hettel, H. J., Fassel, V. A., Ibid., 27, 1311 (1955).
Rare Earth Recovered, y Gd DY 27 27 27 24 25 21 28 25 26 29
Er 25 23 25 27 25
(3) Lerner, h4. W.,Petretic, G. J., Ibid., 28, 227 (19561. (4) Nietzel, 0. TFressling, 1V.t
EtEEj,&,&
~g~,)Atomic (5) ~, Rodden. C. J.. Ibid.. TID-7003 (Del.) io8 ( i m j . (6) Rodden, C J., Vinci, F. A,, “The Metal Beryllium,’’ 13. TV. White, J. E. Burke. eds., p. 645, Am. SOC. Metals, Cleveland, Ohio, 1955. (7) Tolley, W. B., U. S. Atomic Energy Comm. HW-35814 (1955) (declassified 1957). RECEIVED for rsview September 11, 1958. Accepted December 5, 1958. .
