v\n<Y-lt)X7 / 
 
 MDDC - 1087 
 
 \ UNITED STATES ATOMIC ENERGY COMMISSION 
 
 CHEMICAL PROBLEMS IN STABLE ISOTOPE SEPARATION 
 
 by 
 
 Arthur J. Miller 
 Boyd S. Weaver 
 
 Tennessee Eastman Corporation 
 
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 *JBr 
 
 Miy 
 
 This document consists "of 8 pages. 
 Date Declassified: May 23, 1947 
 
 This document is for official use. 
 
 Its issuance does not constitute authority 
 
 for declassification of classified copies 
 
 of the same or similar content and title 
 
 and by the same author (s). 
 
 Technical Information Division, Oak Ridge Directed Operations 
 Oak Ridge, Tennessee 
 
 12-26I-C.».r 
 
CHEMICAL PROBLEMS IN STABLE ISOTOPE SEPARATION 
 
 By Arthur J. Miller and Boyd S. Weaver 
 
 The Development Division of the Clinton Engine«r Works-Tennessee Eastman Corporation has 
 for more than a year utilized the electromagnetic method for separating the naturally occurring 
 isotopes of elements other than uranium. In this program the Division's Chemical Laboratories have 
 been engaged in preparing charge materials for the electromagnetic units, recovering, chemically 
 purifying, and analyzing the separated isotopes, chemically reconditioning the units, and preparing 
 mass spectrometer charges from the isotope concentrates for determinations of isotopic abundance. 
 To date, 19 elements have been processed and concentrates of 63 different isotopes made available 
 to the nuclear physicists and chemists of the Manhattan Project. Most of these isotopes are stable 
 or not radioactive. The concentrates are listed in Table 1. Isotopes of several of the 19 elements 
 and those of silicon, zirconium and antimony are in various stages of chemical purification. 
 
 In dealing with charge materials for the electromagnetic separators, there are several factors 
 taken into account. Of considerable importance is the question as to whether the use of a given 
 material will supply fundamental information concerning electromagnetic operations. Next, for some 
 elements, it must be decided whether it would be advisable to prepare, at considerable expense, 
 compounds capable of satisfactory performance in existing unit'types or whether to modify equipment. 
 Problems in chemical reconditioning of the units such as toxicity of the charge, explosion hazards, 
 and corrosion of the units must also be considered. 
 
 Regardless of how these decisions are made, the charge material chosen is supplied conforming 
 as closely as possible to the following specifications : 
 
 1) That it can be volatilized at a controlled rate. 
 
 2) That it contains a minimum of impurities that will volatilize. 
 
 3) That it contains a minimum of impurities that will ionize. 
 
 4) That it contains a minimum of impurities whose isotopes are isobaric with those to be 
 collected. 
 
 To recover isotope concentrates as more or less pure chemical compounds of known composition 
 is an exercise in chemical ingenuity for each element. The problem generally resolves itself into one 
 of economically isolating minute quantities of the isotope from large amounts of other materials. The 
 extent of recovery is usually determined by balancing the cost of charge material and isotope sepa- 
 ration against recovery cost. For example, if 99.9% can be obtained with one-tenth the effort of 
 recovering the remaining 0.1% the processing will likely cease at such a point. Therefore, it is the 
 continuous responsibility of the chemists to devise low cost methods which provide a maximum of 
 recovery. 
 
 The chemical purity achieved is often influenced by the end usage planned for the individual con- 
 centrate. One requirement always considered is the necessity of minimizing impurities that contain 
 isobars of the element in order tr 'tuain a satisfactory isotopic analysis in the mass spectrometer. 
 Typical spectrographs chemical analyses are shown in Table 2. 
 
 The mass spectrometer cnarge usually consists of a portion of the isotope concentrate converted 
 to a compound suitable for spectrometer operation. To carry out the synthesis without loss of valuable 
 
 MDDC - 1087 [ 1 
 
 ia-2»a-pt-.r-t-»» 
 
2] 
 
 MDDC - 1087 
 
 material or contamination with undesirable impurities is another major chemical problem with each 
 element encountered. 
 
 Interest in most of the stable isotopes is still mainly confined to the field of nuclear research. 
 However, simplification and increased availability of methods for determining isotopic abundance 
 would make them invaluable as tracers in chemical experimentation. 
 
 The future program as outlined by Dr. C. E. Larson, Director of the Development Division, calls 
 for the eventual concentration of the isotopes of \dditional elements including those of the rare earths. 
 
 MASS SPECTROMETER 
 LABORATORY 
 
 Spectrometer 
 
 CHEMICAL 
 LABORATORIES 
 
 Unit 
 
 
 charge 
 Charge 
 
 
 charge 
 __ Isotope 
 
 Determination of 
 isotopic abundances 
 
 Unit charge Prep- 
 aration 
 
 Chemical purification 
 Chemical analysis 
 Chemical 
 
 reconditioning 
 Mass spectrometer 
 charge preparation 
 
 Electromagnetic 
 separation 
 
 of 
 isotopes 
 
 "concentrates 
 Charge 
 
 salvage 
 
 salvage 
 
 
 
 
 
 Isotope 
 concentrates 
 
 MANHATTAN DISTRICT RESEARCH DIVISION 
 ISOTOPE BRANCH 
 
 Figure 1. Material flow in isotope separation. 
 
 12-2 i2- p 3-bu 
 
MDDC - 1087 f 3 
 
 Table 1. Isotopic concentrates. 
 
 
 
 Abundance in 
 
 Natural 
 
 
 
 concentrate 
 
 abundance 
 
 Element 
 
 Isotope 
 
 (%) 
 
 (%) 
 
 Li 
 
 6 
 
 93.91 
 
 7.5 
 
 Li 
 
 6 
 
 87.76 
 
 7.5 
 
 Li 
 
 7 
 
 99.89 
 
 92.5 
 
 Li 
 
 7 
 
 99.91 
 
 92.5 
 
 C 
 
 12 
 
 * 
 
 98.9 
 
 C 
 
 13 
 
 * 
 
 1.1 
 
 Mg 
 
 24 
 
 * 
 
 77.4 
 
 Mg 
 
 24 
 
 * 
 
 77.4 
 
 Mg 
 
 25 
 
 * 
 
 11.5 
 
 Mg 
 
 25 
 
 * 
 
 11.5 
 
 Mg 
 
 25 
 
 * 
 
 11.5 
 
 Mg 
 
 26 
 
 * 
 
 11.1 
 
 Mg 
 
 26 
 
 * 
 
 11.1 
 
 Mg 
 
 26 
 
 * 
 
 11.1 
 
 K 
 
 39 
 
 99.93 
 
 93.38 
 
 K 
 
 40 
 
 0.16 
 
 0.012 
 
 K 
 
 41 
 
 88.36 
 
 6.61 
 
 Ca 
 
 40 
 
 99.95 
 
 96.96 
 
 Ca 
 
 40 
 
 99.97 
 
 96. 96 
 
 Ca 
 
 43 
 
 * 
 
 0.15 
 
 Ca 
 
 44 
 
 * 
 
 2.06 ' 
 
 Cr 
 
 50 
 
 73.76 
 
 4.49 
 
 Cr 
 
 52 
 
 98.80 
 
 83.76 
 
 Cr 
 
 53 
 
 88.59 
 
 9.43 
 
 Cr 
 
 54 
 
 61.0 
 
 2.30 
 
 Fe 
 
 54 
 
 55.47 
 
 6.04 
 
 Fe 
 
 54 
 
 42.85 
 
 6.04 
 
 Fe 
 
 54 
 
 81.06 
 
 6.04 
 
 Fe 
 
 54 
 
 83.03 
 
 6.04 
 
 Fe 
 
 56 
 
 98.41 
 
 91.57 
 
 Fe 
 
 56 
 
 98.70 
 
 91.57 
 
 Fe 
 
 56 
 
 98.62 
 
 91.57 
 
 Fe 
 
 56 
 
 97.42 
 
 91.57 
 
 Fe 
 
 57 
 
 21.10 
 
 2.11 
 
 Fe 
 
 57 
 
 56.13 
 
 2.11 
 
 Fe 
 
 57 
 
 73.01 
 
 2.11 
 
 Fe 
 
 57 
 
 69.63 
 
 2.11 
 
 Fe 
 
 58 
 
 22.0 
 
 0.28 
 
 Fe 
 
 58 
 
 * 
 
 0.28 
 
 Fe 
 
 58 
 
 • 
 
 0.28 
 
 Ni 
 
 58 
 
 98.05 
 
 67.4 
 
 Ni 
 
 58 
 
 98.51 
 
 67.4 
 
 Ni 
 
 60 
 
 94.40 
 
 26.7 
 
 Ni 
 
 60 
 
 87.10 
 
 26.7 
 
4] 
 
 
 
 MDDC - 1087 
 
 
 Table 1. 
 
 Isotopic concentrates 
 
 . (Continued) 
 
 
 
 
 Abundance in 
 
 Natural 
 
 
 
 concentrate 
 
 abundance 
 
 Element 
 
 Isotope 
 
 (%) 
 
 (%) 
 
 Ni 
 
 61 
 
 78.83 
 
 1.2 
 
 Ni 
 
 61 
 
 34.42 
 
 1.2 
 
 Ni 
 
 62 
 
 94.25 
 
 3.8 
 
 Ni 
 
 62 
 
 67.99 
 
 3.8 
 
 Ni 
 
 64 
 
 85.10 
 
 0.88 
 
 Ni 
 
 64 
 
 64.20 
 
 0.88 
 
 Cu 
 
 63 
 
 97.0 
 
 70.13 
 
 Cu 
 
 63 
 
 99.35 
 
 70.13 
 
 Cu 
 
 65 
 
 93.81 
 
 29.87 
 
 Zn 
 
 64 
 
 * 
 
 50.9 
 
 Zn 
 
 66 
 
 * 
 
 27.3 
 
 Zn 
 
 67 
 
 * 
 
 3.9 
 
 Zn 
 
 68 
 
 * 
 
 17.4 
 
 Zn 
 
 70 
 
 * 
 
 0.5 
 
 Se 
 
 80 
 
 * 
 
 48.0 
 
 Br 
 
 79 
 
 * 
 
 50.6 
 
 Br 
 
 81 
 
 * 
 
 49.4 
 
 Sr 
 
 84 
 
 * 
 
 0.56 
 
 Sr 
 
 86 
 
 * 
 
 9.86 
 
 Sr 
 
 88 
 
 * 
 
 82.56 
 
 Mo 
 
 92 
 
 92.07 
 
 22.0 
 
 Mo 
 
 94 
 
 74.68 
 
 9.4 
 
 Mo 
 
 95 
 
 
 16.1 
 
 Mo 
 
 96 
 
 
 16.6 
 
 Mo 
 
 97 
 
 
 9.65 
 
 Mo 
 
 98 
 
 
 24.1 
 
 Mo 
 
 100 
 
 
 9.25 
 
 Mo 
 
 100 
 
 
 9.25 
 
 Ag 
 
 107 
 
 88.96 
 
 51.9 
 
 Ag 
 
 107 
 
 90.26 
 
 51.9 
 
 Ag 
 
 109 
 
 * 
 
 48.1 
 
 Ag 
 
 109 
 
 92.16 
 
 48.1 
 
 Cd 
 
 106 
 
 * 
 
 1.4 
 
 Cd 
 
 111 
 
 * 
 
 13.0 
 
 Cd 
 
 113 
 
 * 
 
 12.3 
 
 Cd 
 
 114 
 
 * 
 
 28.0 
 
 Cd 
 
 116 
 
 * 
 
 7.3 
 
 In 
 
 113 
 
 * 
 
 4.5 
 
 In 
 
 115 
 
 99.56 
 
 95.5 
 
 Sn 
 
 112 
 
 * 
 
 1.1 
 
 Sn 
 
 122 
 
 * 
 
 5.5 
 
 Sn 
 
 124 
 
 * 
 
 6.8 
 
 12-252- P 4-bu 
 
MDDC - 1087 
 
 [5 
 
 Table 1. Isotopic concentrates. (Continued) 
 
 
 
 Abundance in 
 
 Natural 
 
 
 
 concentrate 
 
 abundance 
 
 Element 
 
 Isotope 
 
 (%) 
 
 (%) 
 
 Pb 
 
 204 
 
 7.8 
 
 6.7 
 
 Pb 
 
 206 
 
 75.67 
 
 23.6 
 
 Pb 
 
 207 
 
 61.55 
 
 22.6 
 
 Pb 
 
 20b 
 
 92.10 
 
 52.3 
 
 ♦Isotopic abundance not obtained to date. 
 
 Table 2. Chemical purity of typical concentrates. 
 
 Impurity 
 
 Mg 28 
 
 Ca*<> 
 
 Cu 63 
 
 Cu 6 ' 
 
 Zn 84 
 
 Cd 114 
 
 In 115 
 
 Ag 
 
 N.D. 
 
 N.D. 
 
 0.04% 
 
 0.06% 
 
 <0.04% 
 
 N.D. 
 
 <0.04% 
 
 Al 
 
 < 0.04% 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 0.08% 
 
 As 
 
 N.D. 
 
 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 
 
 
 
 B 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 Ba 
 
 
 
 N.D. 
 
 
 
 
 
 
 
 
 
 
 
 Be 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 Ca 
 
 N.D. 
 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 Cd 
 
 N.D. 
 
 NX). 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 
 N.D. 
 
 Co 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 Cr 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 <0.15% 
 
 N.D. 
 
 N.D. 
 
 Cu 
 
 0.04% 
 
 N.D. 
 
 
 
 <0.04% 
 
 <0.04% 
 
 <0.04% 
 
 Fe 
 
 0.08% 
 
 0.08% 
 
 < 0.04% 
 
 0.04% 
 
 N.D. 
 
 N.D. 
 
 0.08% 
 
 In 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 
 K 
 
 
 
 N.D. 
 
 
 
 
 
 
 
 
 
 
 
 Li 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 Mg 
 
 
 0.04% 
 
 < 0.02% 
 
 < 0.02% 
 
 <0.02% 
 
 N.D. 
 
 0.02% 
 
 Mn 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 <0.04% 
 
 Mo 
 
 NX). 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 Na 
 
 < 0.08% 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 Ni 
 
 N.D. 
 
 N.D. 
 
 <0.08% 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 Pb 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 Pt 
 
 < 0.15% 
 
 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 
 
 
 
 Rb 
 
 
 
 N.D. 
 
 — 
 
 
 
 
 
 
 
 
 
 Si 
 
 0.05% 
 
 0.05% 
 
 <0.05% 
 
 0.05% 
 
 <0.05% 
 
 < 0.05% 
 
 0.31% 
 
 Sn 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 <0.08% 
 
 N.D. 
 
 Sr 
 
 *-- 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 <0.11% 
 
 Ti 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 NX). 
 
 N.D. 
 
 N.D. 
 
 V 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 <0.08% 
 
 Zn 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 
 0.15% 
 
 N.D. 
 
 Zr 
 
 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 N.D. 
 
 NX). - Not detected spectrographically 
 <C - Detected but below limit of determination 
 — - Not determined 
 
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UNIVERSITY OF FLORIDA 
 
 3 1262 08907 9981