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MITNE-14
Equilibrium Extraction Characteristics
of
Alkyl Amines and Nuclear Fuels Metals
in
Nitrate Systems
Progress Report for the Period
July 1 - December 31, 1961
Progress Report X
by
Edward A. Mason
Richard E. Skavdahl
February 15, 1962
Work Performed Under Subcontract No. 1327
Under Contract
No. W -740 5 - Eng - 26
with
Union Carbide Nuclear Corporation
Oak Ridge, Tennessee
Massachusetts Institute of Technology
Cambridge 39, Massachusetts
-
1. 11,
I
I -
-
I II --
,
. I
wqw."W PP" 11
I1 ompll 401pir" P, 11
1
111' 1
-
. I.,...
MNONNINN,
-
.1,
....
..................
_.- -- 11
11
w
" . i
TABLE OF CONTENTS
Text
1.0
Summary
1
2.0
Ruthenium Nitrosyl Nitrato Complexes
2
2.1
Extraction of Freshly Prepared Solutions
2
2.2
Extraction of Aged Solution
5
2.2.1
Comparison of Two Batches of Solutions
5
2.2.2
Effect of Age of Solution
7
2.2.3
Effect of Salting Concentration
7
2.2.4
Organic Phase
Ruthenium
2.2.5
2.3
3.0
Effect of Amine
Concentration
19
19
2.3.1 Effect of Solution Age
19
2.3.2 Effect of Nitrate Salting
22
Ruthenium Nitrosyl Nitro Complexes
27
3.1
Extraction of Freshly Prepared Solutions
27
3.2
Extraction of Aged Solutions
33
3.2.1
Effect of Nitric Acid Concentration
3.2.2
Effect of Aqueous Ruthenium Concen-
33
tration
37
3.2.3
Effect of Amine Concentration
42
3.2.4
Effect of Nitrate Salting Concentration
47
Spectra of Solutions
3.3.1
Effect of Solution Age,
47
3.3.2
Effect of Ruthenium Concentration
49
Uranium Extraction
4.3
- m".-
12
Spectra of Solutions
3.3
4.0
Titration of Extractable
57
Effect of Fluoride
,
I
.
I'll I II-ITAM-
9.1"IM"111111
limp""
MIRF
TABLE OF CONTENTS (Cont'd)
Text
4.0
5.0
4.1
Effect of Temperature
57
4.2
Effect of Sulfate
gy
4-3
Effect of Fluoride
60
.62
References
Figures
1. Extraction of Freshly Prepared RuNO-Nitrato
Complexes
4
2. Comparison of the Extraction Characteristics
of Two Batches of RuNO-nitrato Complexes
Solution
6
3. The Effect of Age of Solution on the Extraction
of DuNO-nitrato complexes
8
4. The Effect of Nitrate Salting on Extraction of
RuNO-nitrato Complexes: Varying Awueous Nitric
Acid Concentration
9
5. The Effect of Nitrate Salting on Extraction
of RuNO-Nitrato Complexes: Varying Aque6us
Total Nitrate Concentration
6.
7.
10
The Effect of Nitrate Salting on Extraction of
Nitric Acid
11
The Effect of Nitrate Salting on Extraction of
RuNO nitrato Complexes: Varying Organic
Unbound Nitric Acid Concentration
13
8. The Effect of Nitrate Salting on Extraction
of RuNO-nitrato Complexes: Varying Aqueous
Total Nitrate Concentrations
14
9. Organic Phase Titration of Sample 128
15
10. Organic Phase Titration of Sample 128
17
11. Organic Phase Titration of Sample 127
-- w-w-
t .. -
"Al"O I
-
I
-a qMM.,
..
", ,
0 P'.
, , ,
I
-
I MOOR"
-
............
...........
............
Oki,
TABLE OF CONTENTS (Cont'd.)
Page
Figures
12.
The Effect of amine Concentration on
Extraction of RuNO-nitrato Complexes
20
13.
The Effect of Amine Concentration on
Extraction of Nitric Acid
21
14.
The Effect of Solution Age on Absorption
Spectra of RuNO-nitrato Complexes Solutions 23
15.
The Effect of Solution Age on Absorption
Spectra of RuNO-nitrato Complexes Solutions 24
16.
The Effect of Solution Age on Absorption
Spectra of RuNO-nitrato Complexes Solutions 25
17.
The Effect of Nitrate Salting on the
Absorption Spectra of RuNO-nitrato Complex
Solutions
18. 1 Extraction of Freshly Prepared RuNO-nitro
Complexes
19.
20.
26
29
Extraction of Freshly Prepared RuNO-nitro
Complexes
30
Extraction of Freshly Prepared RuNO-nitro
Complexes
31
21.
Extraction of Freshly Prepared RuNO-Nitrato
and RuNO-nitro Complexes
32
22.
Extraction of Aged RuNO-nitro Complexes
34
23.
Extraction of Aged RuNO-nitro Complexes
35
24.
The Effect of Solution Age on Extraction of
36
RuNO-nitro Complexes
25.
The Extraction of Aged RuNO-nitro Complexes:
Effect of Organic Phase Nitric Acid
Concentration
38
26.
The Effect of Contact Time on the Extraction
of RuNO-nitro -'39
27.
The Effect of Contact Time on the Extraction
of RuNO-nitro JoGpuxNOsmitrato Complexes
40
IM-1.
PRIM.
..................
TABLE OF CONTENTS (Cont 'd.)
Figures
28.
Page
The Effect of Aqueous Ruthenium Concentration on Extraction of RuNO-nitro
Complexes
29.
41
The Effect of Amine Concentration on
Extraction of RuNO-nitro Complexes
43
The Effect of Sodium Nitrate Salting on
Extraction of RuNO-nitro Complexes
44
The Effect of Sodium Nitrate Salting on
Extraction of RuNO-nitro Complexes
45
32.
The Effect of Sodium Nitrate Salting on
Extraction of RuNO-nitro Complexes
46
33.
The Effect of Solution Age on Absorption
Spectra of RuNO-nitro Complexes
48
30.
31.
34.
35.
36.
37.
The Effect of Aqueous Ruthenium Concen-
tration on Absorption Spectra of RuNO-nitro
Complexes
51
The Effect of Aqueous Ruthenium Concentration
on Absorption Spectra of RuNO-nitro Complexes
52
The Effect of Temperature on Uranium
Extraction
58
The Effect of Sulfate and Fluoride Ion on
Uranium Extraction
59
Tables
1.
Ruthenium Nitrosyl Nitrato Complexes Solutions
2.
Ruthenium Nitrosyl Nitro Complexes Solutions
28
3.
Summary of Ruthenium Extraction Data
53
4.
Uranium Temperature Study
57
5.
Uranium-Sulfate Study
60
6.
Uranium- Fluoride Study
60
Rip
3
-1-
1.0 Summary
During this report period, the effects of solution
age, salting concentration, and amine (trilaura amine
in toluene) concentration
on the solvent extraction
characteristics of ruthenium nitrosyl nitrato complexes
in nitrate systems were investigated. The effects of
solution age and nitrate salting on absorption spectra
of the RuNO-nitrato complexes aqueous solutions were also
studied.
The effects of solution age, nitric acid concentration,
aqueous ruthenium concentration, am:ne concentration, and
nitrate salting concentration on the solvent extraction
characteristics of the RuNO- nitro complexes were investigated. The effects of solution age and aqueous ruthenium
concentration on the absorption spectra of the RuNO-nitro
complexes were also studied.
The effects of temperature, fluoride ion, and sulfate
ion on the solvent extraction characteristics of uranium
were studied.
Results of the work on the RuNO-complexes indicate
that an important variable in the solvent extraction
process may possibly be the concentration of the unbound
nitric acid in the organic phase.
The results of the work on the RuNO-nitrato complexes
indicate that the more extractable forms of those complexes
may be the tetrar and penta-nitrato complexes and that
these complexes may be extracted in the acid forms rather
than the anionic forms.
For the freshly prepared solutions, the RuNO-nitro
complexes are much more extractable than the RuNo-nitrato
complexes at low nitric acid concentrations.
The effect of temperature or uranium extraction
results in an activation energy of AH= - 3.10 Kcal in the
range of 25-500C. The addition of sulfate
mole
ion and fluoride ion to nitrate solutions of uranium result
in a relatively small effect on uranium extraction with the
distribution ratio varying by a factor of two or three.
In"""
PPill.. M IM
II I
I
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2-1
2.0
Ruthenium Nitrosyl Nitrato Complexes
A discussion of the formulas and species of the
ruthenium nitrosyl nitro (RuNO-nitro) and ruthenium
nitrosyl nitrato (RuNO-nitrato) complexes to be found in
aqueous nitric acid solutions is given in Reference (1).
A second batch (batch B) of RuNO-nitrato complexes
solutions in nitric acid was prepared using ruthenium
nitroso hydroxide as the starting material. The compound
was purchased from A. D. Mackay, Inc. The first batch
(batch A) of ruthenium in the form of nitrosyl nitrato
complexes was prepared from ruthenium trichloride (2);
absorption spectra and distribution ratios for the Fatch
A have been reported previously (I).
For the batch B, 45 grams of the hydroxide was added
to 500 ml of 9.2N. nitric acid and boiled for approximately
two hours. The liquid level being kept constant by
intermittent additions of distilled deionized water (DDW).
After cooling, the solution was filtered through a
sintered glass funnel and placed in an evaporating dish
inside a vacuum oven and evaporated almost to dryness,
yielding RuNO(NO ) 2H2 0. The solution had the characteristic deep red clor, as did the resultant sticky mass
after evaporation.
The red mass was dissolved in DDW and the solution
diluted to 250 ml in a volumetric flask. A quantitative
analysis showed the stock solution to have a ruthenium
concentration of 84.6 gm/liter. This quantitative analysis,
as well as all of the following analyses, was done by the
KOH-KNO3 fusion method (2).
A set of solutions was then prepared by adding the
appropriate amount and concentration of nitric acid and/
or sodium nitrate to aliquot portions of the stock
solution. A summary of the solutions is listed in
Table 1.
2.1
Extraction of Freshly Prepared Solutions
Extractions of most of the fresh solutions of batch
B (age after dissolution of the RuNO(NO3 )3 2H2 0 in DDW
approximately 1-2 hours) were made for a two minute
contacting time). The data are plotted in Figure 1.
The curve for the nitric acid system with no salting is
fairly flat 0 with a maximum at about 3N nitric acid. The
values of E range from 0.0060 at 3N HNO to 0.0028 at 8.8N
HNO 3 ; the a#id concentration was varied prom 0.5N to 8.8N
-~~~
lELL-luM
m||M i
. -. -,
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'-,-.v1.:
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RI1.MNI..I
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M-jRIJ
3
TABLE 1
Ruthenium Nitrosyl Nitrato Complexes Solutions
Nitric Acid Cono., N
Total Nitrate Con., M
0.52
0.52
0.89
0.89
1.32
1.32
3.10
3.10
4.91
4.91
6.85
6.85
8.74
8.74
10.08
10.08
0.50
1.22
0.48
3.28
0.46
5*37
0.47
6.20
1.27
3.w16
1.29
5*18
1.27
6019
3.09
5.00
3.10
6.17
5.05
6.35
Ru Cone., m/1
6.45
"I
I,o
If
6.00
6.4
4
FIGURE 1
Extraction of Freshly Prepared RUNO-Nitrato Complexes
Batch B
2-Minute Contacting at 250 C with 0.26 M TLA in Toluene
0 = Nitric Acid System (No Salting)
A = Nitric Acid-Sodium Nitrate System(Total Nitrate
2D'
--6
---
-
-
--
-
T
- -----
-
3
_
-t
-
- 1 1-
L
-
--
-
--
t
4-
+----
L
-4
I
0.10 C
61---
--
--
--
-
..--
---
-
---
-
.
E0
A
4
--
--
--- -- -
-
- -
----.-
6
-----
3-
2
-
-
-
-
--
--
-
--
-
--
-
-
-
7
--
--- - -- - - - --
4-
- . 7
--
-- -
1 - ---.---
-
--
1--
N0
4
T
7It
-0: -
61
-
- a01
rT7
-----
--
-
---
-
-
--
- -
1--4
- --
- -
-
---.--
--
-
--
-
-
1-
T
_
__
~i
3-
r-
--
-
-
-
}-l
t
T
T
~-4-
4-
0
1
u
I
4--
Jj
0.001
*.L
: KI
4
0-
.1 S0
4
!T4
~u>
.
Final Aqueous HNO 3 Normality
2-2 5
The data for a constant total nitrate concenHNO
tralion of approximately 6.2M show a decrease in E0 from
0.0249 at 0.45N HNO to 0.0050 at 5.ON HNO , the dita
falling on a straigAt line on a log-log plet with a
slope of about -0.7. The increase in the extraction of
ruthenium with nitrate salting can be explained by an
increase in the nitrate complexing, especially at the
lower acid concentrations. At 0.5N HNO3 , the addition of
nitrate salting to form a to al nitrato concentration of
6.2 M raises the values of EA by a factor of five.
2.2 Extraction of Aged Solutions
2.2.1
Comparison of the Two Batches of Solutions
The second batch of solutions was aged at room
temperature for one month and then sample extractions
were made to determine if this batch resembled batch A
with respect to its extraction characteristics. Variations
in the preparation methods of the two batches, in
particular the two different starting materials (RuC1
for batch A and RuNO-hydroxide for batch B) could posibly
result in products with dissimilar values of NO : Ru
ratios and concentrations of nitro complexes, i any
exist. A second important variable is the method and
speed of evaporation of the solution to yield RuNO(NO
2H 0. In the two cases, the method of evaporation wa )3
vey similar, in that the same equipment was employgd
and the temperature of evaporation was the same (30 C.)
Extractions were made for a 2 minute contacting time
and a 24 hour contacting time and varying nitric acid
concentration with no salting. The results are shcvn in
Figure 2. It can be seen that, in general, the values of
E are slightly lower for batch B than for Batch A. The
m .ximum variation occurs at 1.3N HNO for the 24 hour
contact time and shows the value of o to be approximately
20% lower for batch B. For the two
nute contact time,
the maximum variation occurs at 4N HNO 3,. when the batch
B value is 35% below that of batch A. It appears that
an even greater variation may occur at very low acid
concentration and that the batch B values may be
appreciably greater than the batch A values. However,
analytic limitations prevent a closer investigation of
this point, in that the ruthenium concentration in the
resultant organic phase would be too small for accurate
In addition,
analysis by the KOH-KNO fusion method.
the differences between the batches seems to disappear,
or at least reduce in magnitude, at the longer contact
time.
FIGURE 2
Comparison of the Extraction Characteristics of
Two Batches of RuNO-Nitrato Complexes Solutions
Solutions Aged For One Month at Room Temperature
Contacted at 250C With 0.26 M TLA in Toluene
0 m
lUMBtch A
on of the 0 Batbn B2hart
:-
1
L
TTT
_
r
-
-
--
8
istic
6
4
-44
--
6
4
t
+
-4
4
6-
-
-t4i-T,
4
N~rW'
3t
-
-;t
-
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I
I
-
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t
v-
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r
II
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11
T_
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-4
rj r
T*
t
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--
-4.-
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t
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T1
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T
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7 i
0.100
0
I
A
-
- -
-t
I--t-
-
-
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--
4
~onV
t
m3
-
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----
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O
tt
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+e
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9
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8
w
7 -
-
-
'
-
-
--
-
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-
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--
-
-
---
-
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-
-
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+ -
-
-
-'
---
-
t
-
2'
- -l
7
----
-
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14h
'
.J
~ -4
-
-
-
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-
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V-
- -
6
5
;'
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-
-
1
-
-
-
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3
-
1
--
2
0.001
I
0.1
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Iq7
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5
0
'
3
4
5
1
10.0
Final Aqueous HNO 3 Normality
67
-
89
10
2.2.2
Effect of Age of Solution
In order to determine the effect of solution age
on the extraction characteristics of the RuNO-nitrato
complexes, extractions repeating the conditions of
Figure 1 were carried out after the solutions had aged
for one month.
Figure 3 shows the two sets of d&ta.
Of
interest are several points. For the nitric acid system
with no salting, distribution ratios of the aged
solutions varied in a manner consistent with the
observation of Fletcher et al (4) that nitrate complexing
decreases with aging at the low acid concentrations and
increases with aging at the higher acid concentrations.
Aging had little effect on the salted solutions at a
total nitrate concentration of 6.2M., indicating that the
freshly prepared salted solutions were more nearly at
equilibrium conditions with regard to the distribution of
the RuNO-nitrato complexes than were the non-salted
solutions. Above about 2.5N HNO3 the data show the salted
solutions to be less extractable than the non-salted
solutions, a condition which is inconsistent with the
usual findings that salting increases nitrate complexing
and therefore,increases the degree of extractability.
However, the increase in nitrate complexing due to the
salting is more than offset by an increase in the
unbound nitric acid concentration in the organic phase
which is caused by the nitrate common ion effect (see
Section 2.2.3 for discussion).
Thus, the net result is a
decrease in the extraction of the complexes.
2.2.3 Effect of Salting Concentration
Using 24 hour contacting times, extractions were
made to determine the effect of sodium nitrate salting on
the extractability of RuNO-nitrato complexes. The data
are plotted in Figure 4 so as to show the effect of varying
aqueous nitric acid concentration at various levels of
constant total nitrate concentration. As a result of
cross plotting, Figure 5 shows the effect of varying
total nitrate concentration with constant nitric acid
concentration.
In Figure 4, above a nitric acid concentration of
about 2.5N., salting appears to cause a slight decrease
in the value of E0 . This apparent inconsistency can possibly
be explained by cAnsidering the effect of changes in the
concentration of nitric acid in the organic phase on the
distribution ratios. The addition of NaNO to an aqueous
nitric acid solution results in an increas in the concentration of nitric acid in the contacting organic phase;
see the data of Figure 6 which were obtained by titration
of various organic phase samples. Nitrato salting can
FIGURE 3
The Effect of Age of Solution on the Extraction
of RuNO-Nitrato Complexes
Solutions Aged at Room Temperature (Batch B)
2-Minute Contacting at 25 C with 0.26 M TLA in Toluene
10
~~
7-4
f7
46
i
-
7
4-- 6
--
4
T4
4-
--
7
2~
-
777,±T
-
-
-
-
A--*
4,ff
--It
-7n+-
-
-
4
T
41
4
-
-
-
--
78L
- -
T ~7
-~-
-TT-
--
---
--_--
4-i
~-t
t
- T
r
-~-~I
-
t
-
-
1.
----
-
-1
-
l
I
t
1- -4
0.01009
-
-
9
I,---
-
I-4
3
-+----
.
- - - -
-4
o_
_
---
.
4.2
-
--
-
-
-r
-
.
-
------1-r
-
-
- -n
1
-_
-
-i14-1j
-
r-
.11
~
~
~
n
O
414
91
-
L-O.O
Final Aqueous HNO,
-
Normality
2
-
--
-
-G 3
- -
-
-1L
-
3
y~~---
-
-
-
-
-I4r-v-
+
-
-
-
-
-,
--
-
_
t
-J - -1
-
--
t
~~
- ---
WT~~
+
--
-
-
-
A
-
-
-
I
isI
-----
-
-+
-
Fl
-I
-
44-
T
-T--
-
- -
-
Q -
it
---
T
1
-
-
I~
-7-
4
L
.~
0
-
T
-
-
6
1
-
- -pt
4
5
678910
6781
FIGURE 4
The Effect of Nitrate Salting on Extraction
of RuNO-Nitrato Complexes
Solutions Aged for One Month at Room Temperature (Batch B)
24-Hour Contacting at 250 C with 0.26 M TLA in Toluene
Salting Agent = NaNO3
10
F
7'$-
H-H-4.i
t1-
7
-
a
c
-z:
- --:
tt-
-
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5
ri
M -
4
-
t
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$o'r
4i
4 -
-
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C
t
-
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I-
t
-
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r
1
r-
p
1
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w
0
11
:V ,
9-~~'
7-r,
L
t
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43
L
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15"
A-
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r
:
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1,
4
4
0
-J
-w-
4BT11411
4,.,.,-,
.010 'i
1.5
0.1
2
ti; t:i;
41 {L
T
H-
V
TI,
2.5
3
4
6
47
7-1
'IT
7
4
4T'
8
8 6 99 10
10
-
T
tM t
'4H ii'-'
15
152
t+
2
.5
2. 5
1.00
Final Aqueous
HO3 Normality
3
4
4
F
5
6
7
8
9
%
FIGURE 5
The Effect of Nitrate Salting on Extipaction
of RuNO-Nitrato Complexes
10
Solutions Aged For One Month at
Room Temperature (Batch B)
244-our Contacting at 250C With 0.26M TLA in Toluene
Salting Agent = NaNO
3
4
10
9--
T--L
1
t7
4~
1
L
-
-
7--r
,
~TIi ~:
-
7-
n-
14
-r-
L
44
94
-x.
-
T
n
---
t 7-,
-
2
Z
z
3-
i
-
3
ft
-
2- T
-
-:
1-
-
tL
25-*4
-
. 4.
-
-
--
!T
L
if
~"
-4
-
'14
4
I
-
T
:
t
-
n
4-1
t
-1
4
6
r
+
±
.5
0
t
T
--
-
_ _
z
z
? 4-j-
7.
1
-
d
nt
1-T
T
-V1 r
-
41
r
rT
th
U
1
'
15-L
E0
0.10
+
2.
I
4
.4
~..
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-----
7-74
-
. ----
--
4
tL
6-
-
p4-
T~~~~I
-
-
-4
-14!
r
-4
r
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--
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t
w
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1-54
U
N
t
2
0
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LT
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0.010
-~
L ' L, 11 1 ,
I'
- -1.;
1 -ILLII I 1II1II1II , A! '.J
1.5
ii
Fr
IF2.5
4
5
6
7
IIL ,
8
-j '
I 10
1.0
I
.4'
1 1 1.
1.25
I- . L .5
3
Final Aqueous Total ITitrate Concentration, M.
s
10
In
INCH
359-11
7!10 X 10 TO THE %/
Z7 K EUL)F FE L a
E !mS E.1 L
-
--
I
I~~'41i
TO- TH-1:
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W
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A.
3 91
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A
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---------------
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... .
.
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.+
e
.
i Ir--
--
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e
fr-
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----
t
.
-
4
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-
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----
41
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----
--
4-
.
---
----
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- -
T
1-d-IT- -
- -* i-T
-
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---
.-
-
-
-
-
-Y
i t
--
---
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-
+
--
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--N--1-
-r
-
it
4--
---
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--
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-- -
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+
2-5
12
be seen to cause a substantial increase in the amount of
unbound nitric acid in the organic phase.
A more meaningful correlation of the ruthenium
extraction data can be obtained by plotting E as a
function of the final concentration of the oranic phase
unbound nitric acid at various levels of total aqueous
Of significant
nitrate concentration (see Figure 7).
interest and importance is the fact that this method of
correlation yields the more logically expected trend, i.e.
as total nitrate increases at constant unbound HNO , E
increases. The inference is that the values of th; pakition
coefficient of the individual complexes are dependent on
the concentration of the unbound HNO in the organic phase
0NOin the aqueous
rather than on the concentration of
Therefore, in order to more fuliy investigate the
phase.
effect of nitrate salting at constant HNO concentration,
the organic phase unbound nitric acid shold be held
constant rather than the aqueous phase nitric acid, as
was done in Figure 5. Figure 8 illustrates this point by
presenting the ruthenium extraction data for both constant
aqueous phase nitric acid concentrations and constant
organic phase unbound nitric acid concentrations. The
values plotted were obtained from Figures 5 and 7. When
compared on the basis of constant concentration of
unbound nitric acid in the organic phase, ruthenium
extraction is seen to increase with increasing nitrate
salting of the aqueous phase the slope of the EO vs. total
aqueous nitrate curve on log-log paper is approimately
1.3 to 1.7 for the condition of constant concentration of
unbound nitric acid in the organic phase.
2.2.4
Organic Phase Titration of Extractable Ruthenium
A very interesting result of the organic phase
titrations discussed in the previous section was the
apparent titration of extractable ruthenium in the organic
phase. This was observed for samples having a relatively
large concentration of ruthenium (approximately 2.5
gm/liter).
The phenomenon was first noticed when the organic
phase of sample number 128 was titrated and gave a value
of 0.103 M for the difference between total acid and amine
nitrate concentration. This difference is normally taken
to represent the unbound nitric acid concentration.
Sample 128 had a final aqueous nitric acid concentration
of O.37N and a final aqueous nitrate concentration of 6.1M.
From Figure 6, the eXpected unbound HNO concentration
would be about 0.055M, a factor of about two less than the
0.103 M value. Closer inspection of the titration curve
(Figure 9) revealed that a total of four inflection
points rather than the customary two points of inflection
were possibly present.
4
FIGURE 7
The Effect of Nitrate Salting on Extraction
of RuNo - Complexes
Solutions Aged for One Month at Room Temperature (Batch B)
24-Hour Contacting at 250 C with 0.26 M TLA in Toluene
Salting Agent =.NaNO
3
4-
-
4
74
8
-T
7-
--
-
-
T TT'~
0
t;
P
t
-
-
-
--
---
-
.-----.-
-
-
T
-
:-It_4,
-
I
T
-
j4
-
-
-
-
4!
-Z
T-
--
4-
-X1
13
--
I
r;
t
w
I
4
(a
--
#4r
!
17'r
-4-4:
--
.
w
U
- --
0
I-tj
-
--
--
7
-
r
-
--
--
-
--
-
-
T-4-1'
r
I.
~
T
-
-
27,
:4
I
A
0.100
1-
77-;
424 2
p ii:
Tf1
1
0.0 1 0
Tj
L 4'-*-j
U
44
7'2
++~~
-1+
i
T-:
(A
I-i_
42
1741;
T 'T-
U
U
IN
i -1h4 -4 -
T
-
L~
2~71-
X
7
T
-
I I;i
L-4
0
1-4
--
Rt~
'L7Eii
0.0101
I
0.01
1.5
17-
44
I - ~:~'
K244~
-
1
1rIV
''
I77
'4.-
-'
2
74
2.5
3
4
5
6
-
8
K
H
;TVj
THThHzI7
4-,1-,
7
f
9
10
1.5 L
1.5
-
2
,4
2.5
0.10
Final Organic Unbound HNO3 Normality
,IjjT
3
2._
4
-11
5
7
4
<p
14
---
'10~~
-
-
-
5---.----
1
-
-
--
T
-
It
J,,A
1
-
-
-
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1
L
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s
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3
--
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8
-o
7
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-j-
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o0
U) U
6
-
.~~~~~~;.- - - -
- ---- -
l
-_--
.iti
(n
- --71
4 --
-+-- ----
-,-5*
Finl
Finl
Aueus
1
otl
qu~os
otl
itat
Ntrae
IOlArit
olait
-
-
-
-
-
Figure 9
is
t
Ft~
U
LO
I
I.
n
4
o
S-n
x
O .i
-A.
IT
I.
ici
t
t
,I
1:
t1~K4KKVKf"i..
-IIL-
1.
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--
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-
I LLI__I__iiL1~Ir
KI2.
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-7-4 -j- H_-I--t
F~
--
4inl
iat
t
-]
- - -
-L-
L
-
1
T
2-6
In order to investigate this phenomenon, the sodium
hydroxide was diluted by a factor of five (from 0.0875N
to 0.0175N) and the sample titrated again. Figure 10,
which shows the result of the re-titration, covers the
range corresponding to 0-1.3 ml on Figure 9. As can be
portion of the curve yields
seen from Figure 10, the first
The
at least two inflection points and possibly more.
would
as
0.059M,
first corresponds to a concentration of
inflection
acid
be expected if this were the unbound nitric
point. The difference between the first and second inflee-'
tion points corresponds to a concentration of 0.038M.
By previous quantitative analysis the ruthenium
concentration was found to be 2.38 gm/liter, 0.024M. If
it is assumed that the ruthenium in the organic phase is
mostly in the form of the acids of the tetra-and pentanitrato complexes of nitrosyl ruthenium (i.e., HRuNO(NOA
(H 0) and H RuNO(NO ) 5) which are neutralized between tWi
twg end poi ts markad on Figure 10 and if the mole
fraction of the penta-complex is represented by X, then
2 x (0.024) +(l-x)0.024 = 0.038
and X then is equal to 0.,58. The resultant concentration
of the complexes are 0.010M and 0.014 M for the tetraand penta-, respectively. Even closer inspection of
Figure 10 shows- an irregularity in the titration curve at
about 5.25 ml. If it is assumed that the entire pentacomplex would be titrated before the tetra-complex, then
for a concentration of 0.014M, its neutralization would be
calculated to occur at 5.40 ml (which is very close to the
inflection found at 5.25 ml).
Other samples with large ruthenium concentrations in
the organic phase were also titrated. At concentrations
of less than approximately 1 gm/liter, the results of the
titrations are inconclusive. However, sample number 127,
with an organic phase Ru concentration of 2.51 gm/liter
(0.025M), gave very similar results to those of sample 128.
The aqueous phase ofFsample 127 was 0.35N HNO and a total
rom Figure 6, the unbouna nitric acid
nitrate of 5.26 M.
phase would be about 0.044M.
the-organic
in
concentration
(Figure 11) yielded end
phase
organic
the
of
Titration
The first end point gives
ml.
4.60
and
ml
points at 2.55
difference between the
the
and
0.045M
of
a concentration
end points corresponds to a concentration of 0.036M.
Again, assuming the Ru to be mostly in the form of the
acids of the tetra- and penta-complexes, the mole fraction
of the penta complex is calculated to be 0.44 and the
concentrations of the complexes are calculated to be 0.014M
and 0.OllM for the tetra-and penta-complexes, respectively.
11'r_ f14j1fjjj,'f
1-j#1 1
'T
IT
4i7.JKU:
.T
---- 4Vi
I
.
w0 . . I A
r
4r, .-
Li.,
-14
171 11- L 4
4
11i
Vti1~f1
I
4*tI
-,-t
.-
- it
-
-44
-
I.
-. ---
-I
-
- -
-nk
-.
4-*
--
-- --
-.
-
-
-
-
*- -~
-
o1.
-
-
-
-t
-~
_7-h
- *------
- - ..
11
Z
X
O.
7---
-3
-
.- --
-
rf
-
TT
--
-
----
TIt 7
..
t
4
. . .-
TT
18
I
-4
-T- -
I
L
L
---t
- -
I
52-\,
tt
T
4q
41
34_.
{T
--
T
1
--
T
TTir
-J
x4
11-1
-
-
-
1r
-
r
r44
--
04.
WA]
-,-
-
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K+
-Tt
t-
__-
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I~
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---
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-4
1
1
7
-
19
Although the titrations of samples 127 and 128 and
their resultant interpretations do not present conclusive
evidence for the more extractable forms of the RuNOnitrato complexes, the indications are that the tetra-and
penta-nitrato complexes of the nitrosyl ruthenium nitrato
system are more highly extractable than the lower complexes.
2.2.5 Effect of Amine Concentration
A variation of TLA concentration was made to determine
the effect of amine concentration on ruthenium extraction.
The amine concentration was varied from 0.053M to 0.26 M.
Th8 extractions were made for 24-hour contacting time at
25 C. The aqueous phase contained aged (one month) RuNOnitrato complexes in 1.3N HNO solution with no sal ing.
The data is presented in Figule 12. The value of E is
seen to be initially dependent upon the 1.5 power o the
amine concentration. Above an amine 8 oncentration of
approximately.0.13M., the values of E fall below the line
of slope 1.a. The reason for the faling-off of the
values of E can be seen from Figure 13.
Figure 13 shows
the concent ation of unbound HNO3 in the organic phase as
a function of TLA concentration.
It can be seen that
above an amine concentration of about 0.13M, the values
of the unbound HNO concentration deviate from linearity
and are larger thaA would be predicted. This could result
in a decrease of the partition coefficients of the
extractable species (See Figure 8) and therefore a lower
value of E0 than would be predicted.
A
2.3
Spectra of Solutions
As a means of obtaining information about the aqueous
solutions of the RuNO-nitrato complexes, in particular the
effect of aging and the effect of salting, spectrophotometric
studies were conducted. The equipment employed was a
Beckman Model DU Spectrophotometer and 1 cm absorption
cells. The wavelengths investigated ranged from 400 mp,
to 540 m . Below 400 m±, the absorbance increases
greatly and above 540 m , it becomes very small. Previous
spectra (3) of RuNO- nitrato solutions have shown that an
absorbance maximum exists at about 475 mp and that the
value of the absorbance at this wavelength increases with
Increasing nitric acid concentration.
2.3.1 Effect of Solution Age
In order to obtain some idea of the amount of time
required for the aqueous solutions to reach equilibrium
with regard to the distribution of the complexes in
solution, spectrophotometric studies were made of the
solutions at various solution ages.
FIGURE 12
The Effect of Amine Concentration on Extraction
of RuNO-Nitrato Complexes
20
Solution Aged for One Month at Room Temperature (Batch B)
24-Hour Contacting at 250C with 1.3N HNO Aqueous Solution
of RuNO-Nitrato Complexes; Initial Aqueots Ru=6.45Gm/liter
Tr
f-trr --
-
--
t
-_
u-
+F-w
7-_+-_-_--
--
-,--
-
-*3
;j_~~~'F
-
-
-
--
-
tF
r
4
-
T4
-7___,1__tR
-
"1
4 7 1
*
--
-
_
-
-
-
I
--
4--+- ---
-
T-t
-
-
-
3
2
-ila
-
-
-
-
r
-y
4~
-
4-
--
4-
t-
z
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j4I.5-
2
2
-T
4
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51
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--
T-
lit
PP
4
r
tI4.
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4 vi
5
0
-i
EA
A
0.10
4
1
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c
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Hi
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7, .
F-4-F-~- 4
1
1'1
-.4
t
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A-4 4~-
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.
4-1:
;
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1
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4Ff
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n~~4Ij71
A.
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r
;
t-i
7
-i 1t~
t
-I '---'1-
0
42 +
Tt'
~1,.
3
*F-~ -
i41I FT
I-'
I F-'1,1
2.5
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- -. 1--F-F--
4
1
2
-1'
LF
iF
-T
1.5
t
tI-
-0A
--
0
0.01
-
.
X
1
~L
T
r.
-4
-
--
+
'IT
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5
F-,
T"
_1
7
U
*~-It-Ki.
.4
7r
_T
T
-.
T11
VI
-
4
1+
F,-
I41
5
2
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F I1
44-+44
6
'T
414
17j' t
.141FIlj.
I 4-j
7
8
9 10
-
TK'V44
1.5
2
0.10
Molarity of TLA in
4
-
-1
2.5
4
--
Toluene
HT
.4
11
~5
i
t+ 6
8
44
9 10
Figure 13
tI7
7L7
--
-
-4T+-t
21
t
t
-t,4
-
4
tL.
-I
H4
t7
44
-
1
7It
- -p-4-rj
--
-
r
1
-
--
-
i-
~
14
~
r
-
I
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+
-tr
4
4:
4
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~J
r}
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--*-- -t
I-
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7
i i-
---
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r
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Q
0 F
447
--
--
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~
r~-
,---
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j--*
,IT
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,-O
.
~
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4-4
t
1r
,0-
-+
+
r *
-
.
.
-
.
.
*I-
-
-
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-
-.
-
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T
-
--
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*
4
4
1V.
T4:
;,
2
Li
.+
4
4
4-
22
Figures 14 and 15 show the spectra of a solution of
RuNO-nitrato complexes in 4.75N HNO (no salting) with a
ruthenium concentration of 1.78 gm/iter as a function of
6olution age. At any wavelength up to about 500nl, the
absorbance exhibits a maximum with increasing age.
However, the maximum absorbance occurs at about 475 mp,
regardless of solution age. In Figure 14, the solution
age is shown from 1-2 hours to 22 days. Little change is
seen between 16 days and 22 days. Figure 15 shows
solution ages of 22 days and 31 days. Essentially no
change is discernible between the two.
Figure 16 shows spectra of a solution of RuNOnitrato complexes in 1.2N HNO (no salting) with a
ruthenium concentration of l.3 gm/liter at two solution
ages, one month and six months. Once again, no appreciable
change is noticeable. The conclusion to be reached from
the previous spectra is that equilibrium has been attained
in less than 31 days and probably in the range of 16 to
22 days.
2.3.2
Effect of Nitrate Salting
In an attempt to determine if the distribution of
the RuNO-nitrato complexes in aqueous solutions is
dependent only on the total nitrate concentration or only
on the nitric acid concentration or on a combination of
both, spectra were taken of three solutions at aged
conditions.
Figure 17 shows that the NNO salted solution
spectrum is intermediate betwee the solution having a
nitric acid concentration equal to'the nitric acid
concentration of the salted solution and the solution
having a nitric acid concentration equal to approximately
the total nitrate concentration of the salted solution.
Spectra at other solution conditions are yet to be made
before an analysis of the data can be attempted.
i~I
7-Lib
23
ml
-rn i-711
--
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lt
-
t
4- -
-
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I
1
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N--1
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r
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4
---
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-
--
~-------------"-*-"-------------------------------------------g
-
.41
V
- t
-
---
-
-
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I
2
-
~
-c~
t
-
--
----
-
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--
-
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--
r
-t-
-
U-
--
-
-
,
4
4
-
-
1,~
-
4-
1
r4
4
1
4
1
I
a
I
t
-
4-1
25
-4t
4 -
4S L
4i
.t
TL
+4
4
4
11-
I
N
T_
-i
- -----
T
lLj
-~
-
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~
------
-
4~~~~~~~
_
-
TM
-4
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---
-
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r
-------
--
-
*4
s+-
-
--
At
-
+-
-
*t
--
76n4Tl
++--
----
e---
-
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-~~
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--
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4
-n
-
-f--
---L
44-
t
*-
II
2+ ~'.T 4 ra 4~(
--
-
-
--
I
7-T
-
-
T
-
4
'440
-
-
2 V
--
-
-s. -
- ----.
T
- - - - - - .. - - ---..e- -
zI
p-
£.
-
.
-.
4
I1
-
-
-
-4-
4-
_4
4I-
44T
.4--
--
- -~ rT-4
-
-..-
-
--.--
I.
4
.
-~
-.--
--
,.--
_
1
.
.
.
(Y)
-
1
~~~
-T
L
04
--
4-r1
---
-
-
4--
-
-
-
---
-
--
-
-
-*
-
-
_
__I
0
11
4
Ow
44-4
X
I-
.......
C
-
-1-
I~~
-
-1
~
~1 ---t
--
.--. ...
-
- ..
r
-.----
-
-.
-
-
-
-4
-
-
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*-
*
r**
--
-
-
-*-
--
t
-
- L
--
-_-
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27
3.0
Ruthenium Nitrosyl Nitro Complexes
Concluding the description of preparation III as
started in the previous report (3) the solution was
evaporated nearly to dryness and7yielded a deliquescent
The solid was
brown-orange solid RuNO(NO ) OH(H0) .
in a volumetri
dip olved in DDW and dilutes o 258
flaak. Analysis showed the ruthenium content to be
55.3 gm/liter.
A set of solution was then prepared by adding the
appropriate amount and concentration of nitric acid and/or
sodium nitrate to aliquot portions of the stock solution.
A summary of the solutions is listed in Table 2.
3.1
Extraction of Freshly Prepared Solutions
Extractions of most of the fresh solutions (age
after dilution of compound in DDW approximately 1-2 hours)
were made for a two-minute contacting time. The data
are shown plotted in Figure 18. Of interest are three
observations:
(1) The curve shows no maximum but decreases
steadily with increasing nitric acid concentration. In
fact, plotting the data for the nitric acid sy tem with
no nitrate salting on semi-log paper (Figure 19) yields
a straight .igfthat can be described empirically by
where N is the nitric acid normality.
EA = 0 .2 6 e
(2) From Figure 18, it appears that sodium nitrate
salting decreases the extractability of the freshly
prepared nitro complexes. However, by plotting the
values of E0 against the final organic phase nitric acid
concentrati n rather than the final aqueous phase nitric
acid concentration, it can be seen (Figure 20) that
actually the salting has no observable effect. The
organic phase hitrabiaifc
hCefttDfRtohu ayagotb
ethined by
from
obtained
was
but
the
samples
of
Mrgn& phas6.titration
Figur f.
The freshly prepared RuNO-nitro complexes are
more highly extractable than the freshly prepared RuNOnitrato cemplexes, particularly at low acid concentrations.
Figure 21 shows the two systems plotted so as to enable
At 0.5N HNO3 , the value of'E9 for the nitro
comparison.
complexes is a factor of3approximately 40Atimes that for
nitrato complexes.
The effect of sodium nitrate salting of the RuNOcomplexes, as shown in Figure 20, is negligible.
nitro
This would indicate that neither replacement of the nitro
ligands by nitrato ligands for higher nitrato complexes
formation has occurred in the 1-2 hours of solution aging.
28
TABLE 2
Ruthenium Nitrosyl Nitro Complexes Solutions
HNO
Cone.,, N
Total Nitrate Conc., M
gm/liter
RuConc.,
5.43
0.42
0.42
0.77
0.77
1.22
1.22
2.94
2.94
4.51
4.51
6.29
6.29
8.22
8.22
9.60
9.60
0.42
1.00
0.41
2.99
0.38
4.96
0.36
6.34
4.94
1.16
2.94
5.43
1.07
4.85
I"
1.01
6.26
4.94
2.97
3.07
5.43
2.76
4.86
2.60
6.33
4.94
4.60
5.10
5.43
4.31
6.58
4.94
It
if
it
It
If
A'
FIGURE 18
Extraction of Freshly Prepared RuNO-Nitro Complexes
2-Minute Contacting at
25 0 with 0.26 M TLA in Toluene
0 = Nitric Acid System (No Salting)
A = Nitric Acid-Sodium Nitrate System
(Total Nitrate = 6.3M)
10
-
-
-
.-
8
7
,
-
-.
r
-
-
-
-
29
-
-
-
-
-
-
-
-
-I
-6[-4
4 3
-----~ -
-
.-
-- ---
--
--
-
-
-
-
-
Il
4
--
-
--
-
- Hr-
--
1 -
-
4
_____
24
-
~-
--
+
4-
-
-1441
1
-
-
I1
7 1-
0.100'1
-1tT
-
liT
7
I
f~
T
T
j
-
8
-
0
r
---
'-,--
9
-
----
--
7
6
--
44
1
1
i
--
I
-
00
r
3
-
L,
w
- -
-
-
f
iT
-
t--I-
Lli*---
--
I
9
1;
060
--
-
- ±
-
-
-
7
2
-J
6
5
3
-1
4-
H
-
--
-
tt
4-
0.0011
-
4t
'I
6
7
110
2
3
4
5
6
7
8
Final Aqueous HNO3 Normality
2
3
4
5
6
7
8
9 10
.R;qI-uwolq COPIH snoortbl TeuTgT
r
0
r m>
rn
(AJ
00-
n19.
61 Rg~flQLIa
FIGURE 20
Extraction of Freshly Prepared RuNO-Nitro Complexes
2-Minute Contacting at 25 0C With 0.26M TLA in Toluene
0 = Nitric Acid System (No Salting)
A =Nitric Acid-Sodium Nitrate System
(To 1 1itra e=
t
'-i1- 8
K
.
4
,
---
----
_--
-
--
-- -
--.
- -T-
--
-
-
-
--
4
i
4-
1--4-4II
-'-
1--
tt
-
4
-4
-
-
-t
*
*
11A
8
31
4------
-
-
0.100 10
-
--
- -
F-
-
--
-
t
-
T
. . ..
T
t
----
---
-
--
tt
A
--- -----
-
3
-
- u7
-
-
--_
-----
b
4
-
-
1fl-
0~
t
4-r
-
-,---
--.
__-
--
-
-
-
-
-
--
--
-
--
-
--
---
-
-
-
*_
-
N
-
Opl0
-
0
-U>-
---
-
U(K,U
-
-
.
-
--
-
------
I
.
_
4-m
~ ~
7 -1-
---
7 -
----I--
-
.
' -
-
-
-
-
-
--
-
-
-
-
0 X
(~rVY
~
2
-,~
3
-I
...
-.
1
,1
0.001
.
-
----
-
i
*
-
a
Final OrL;ani c Unbound HN0
.
3
Normality
--.
--
-
>
FIGURE 21
Extraction of Freshly Prepared RuNO-Nitrato and
RuNO-Nitro Complexes
32
2-Minute Contacting at 250 C with 0.26 M TLA in Toluene
0 = RuNO-Nitro Complexes
A = RuNO-Nitrato Complexes
10
8
--
rr
-
7
6
5
- -
-
-
-+4+- -
-
1
i -
-
-r
. A .I - .--- - -.-
1
----
-
-
-K
4
4-
--
-
4-
-
-2
-
tt
-
-+7
- ~ -
-,-+
-
h
-4-
- -
-
-
---1.
1-
-
-- -t-4± 4
-
--
-
--
-. ~
-
-1
4-41
-
''t
4
t'
-
-
--
9
1
-
'H
---
4-
-
-
--
441
t
-
-+ ---
-
4r
--
--
-t-
- -
-
-
-
--
-
) ~
2
44
{I,
-
0.100
E0
A
4--
-
-- ---
+ -4
4
---
---
-
--i -
--
.
.
-
-44:
10
2
-
t
-
34-
-
-
--
4-i-
4 .-.
-44--4
~
-
-4
--
--
-
-
---
-
-
- .144
9
--
84
F
-
-
-
2:
t-
-
4
1
;+-- - -4------:-- - -----
--
-
-+-
-
--
-
-
K. 1.
44
--
-
----- -4
-
-
--
-
-
--
.--
101
2-
0 W
'14-
6~
.:
0-
44
0.001
J
Final Aqueous
5
40N3 Normality
62
-
.0
3
4
5
67$8
9 10
33
This is consistent with the work of Brown (6) on the
RuNO-nitro complexes reaction rates.
3.2 Extraction of Aged Solutions
After aging at room temperature for one month, a
series of extraction studies were conducted on the
solutions.
3.2.1
Effect of Nitric Acid Concentration
A set of extractions was made for two-minute
conctacting of the aged solutions with the acid and
nitrate concentrations in the samples the same as those
for the freshly prepared two-minute contacting. The data
is shown plotted as a function of final aqueous nitric
acid concentration in Figure 22 and as a function of
final organic excess nitric acid concentration in Figure
23.
From Figure 23, it is seen that after aging for
one month, the sodium nitrate salting has had the effect
of increasing the extractabiltiy of the complexes. It
is believed that this is due to either replacement of
nitro ligands by nitrato ligands., the formation of
higher nitrato complexes, or, more likely, a combination
of both.
Of interest is the point (in Figure 23) at which
the line of the salted sample merges with the line of the
non-salted samples. The intersection is not at the
organic phase excess acid concentration corresponding to
6.3N HNO in the aqueous phase, but at a lower point.
This is donsistent with the previous discussion of the
spectra of salted RuNO-nitrato complexes solutions in
Section 2.3.2 and indicates again that nitrate in the
form of nitric acid is more effective with regard to
nitrato com lexing than is nitrate in the form of sodium
nitrate. This may possibly indicate that the tetraand penta-nitrato complexes exist in solution in the
form of the acids of the species (HRuNO(NO ) (H 0) and
)
H RuNO(NO3 5 ) rather than as anions (RuNO(
2
RuNO(NO )
3 5=
Comparison of the aged RuNO-nitro complexes with
the freshly prepared RuNO-nitro complexes (Figure 24)
shows that aging has resulted in decreasing the
extractability of the complexes, although it appears
that at an acid concentration of approximately 7NHNO
3
and higher that the extractability may have been increased.
1~
.4
22
FIGURE 22
Extraction of Aged RuNO-Nitro Complexes
Solutions Aged For One Month at Room Temperature
2-Minute Contacting at 25 0 C with 0.26 M TLA in Toluene
0 = Nitric Acid System (No Salting)
A = Nitric Acid-Sodium Nitrate System (Total Nitrate=6.3M)
10 -,---
-
~
IA1T
- - --
-
-f-
-
-
r
6
--
-
-
44
-
-
-
-I T
_
-t
--
-
-
-
-
--
---
__-__-_-
-
-
-
7T.
-
-
-
_
I
--
-
-.-
-.-.-
-
-
--
--
-
-[-
-
-
.1-1
- -.-
7
r
14
+ ---
-_
-
2
0.100
- -- - - -
-
-- - -
-
- 1
-
-
*-
p
i
1
7
- --
-T
*
--
--
-
ti--
--
-
-, -
-
--
-*----
-
--_-_
-
L
6
-
4
-7--
-
7--
-
-- --
--
-
--
--
-
--
-
--
I
-
-
-
-
- ---
-
__
* -H4.
- --
-
I
N
--.
t -
I..
4-
--
.3
6u
------
- -
- ----
- --
--
---------
-
fIi
Uxn
}.
.
Aj >
-.-..
-
-
, --
LU
X
o
-- 4U
0 0
0.001
77-
J
5
0
3
4
5
6
7
89 1C
11
Final Aqueous HNO3 Normality
rJ
FIGURE 23
3-5
Complexes
RuNO-Nitro
Aged
of
Extraction
Extraction of Aged RuNO-Nitro Complexes
Solutions Aged For One Mogth at Room Temperature
2-Minute Contacting at 25 C with 0.26 M TLA in Toluene
0 = Nitric Acid System (No Salting)
A = Nitric Acid Sodium Nitrate System (Total Nitrate= 6.3Mf
10
-
-- ----
1-
-- K
t
-.--
-
6.
-
-
A4
--24-A
-L4
-.....
-
y-
t
--
4j-
*
*
1
41ti ;
-
-F4-
4
-,
-
4-
{
L
1
IT
i
101
-----
-
.--
1-7
-
---
-
-
t r1
-4-
-
--+--- -
4
-I-
----
4-
-
r
t
-
10
T
74~
--
4-4-7
--
87--
5 -4
-,
-tT
--
-
-
-
.- -
-
744+7---
---
-
-
-
-
-
-
-
-
-
-
5-
-
--
t4
-
-
-
-
--
-
44
-
____-7-
*
0.
'
~
5
-i--
4 4-
-
e
-
-
-.
.
-
--
-
-
-
-
-
6 .
.
II
6o
4 -
-
-.-
--.
-
-,
-
4 7
-
-
-
-
-
-
-
- -
-
-
.
Z
L X
U>
Ow
ow
-
<L
7p-+
-
-
- -
-
--
10---
-
4
-
-
--
--
r
1
5
--
--- -
3
U . 0.L
-
-T -
.---
~ ~
4~-
4
t,*~-
'
'
-
7
-4
-
--
-
-
-
-1
TT- - -1
-L
-.-
*~
-
-
-
-
-
-4-
-
- -
--
-
-
-t-
4
-2
-
-
-
TW
-
A~
6
t
C.
0
Final Organic Unbound HNO3 Normality
--
- -t1
- j i
18-
-
36
FIGURE 24
The Effect of Solution Age on Extraction of
RuNO-Nitro Complexes
2-Minute Contacting at 250 with 0.26 m TLA in Toluene
10 = Freshly
repared Solutions
A = Solutions Aged for One Month at Room Temperature
10
-
-
T-
h
6
-4
J7
T-
.
-
--
-
-
1
'
-
4.i----
_4
4
4~
T-.
4
44
--
I
-I-
V-
S
---
2
I
4--V
u
4
11-
-
-
1
--
_- 1+
1:
'
'i-r
L
I-
t
-
---
~
2+~*
K1 ~ ~ ~
21
*
-- r
-
-
-
11 I-
Vt
--
--
-+-
t
T
1
-
t
6
t
-&-
4
-
-
-
T
-
-
1
1-1--
-
--
-
-
06
U)
U
~
-4
105
1
-
L
-
1
4-l
4
-- 4-
1-4-
-4+
-
-----
-
-4
-I
4
±
-
+--A
5
T
-
-
-
6
~4J
-
-TiI
7
-
-8
-
t-+
p
77
-)
-
-T
4
-I-
f1
+-4*-
9
-
K
-L
-
-
t
T
L'4
H
K~~~~~~~~
F
-
K
i
T
-t-T
-
K-,
1
4
t
I1-2:
-
8
~
-
-
LL
IC~
10
-
-
-l
3
,
-
I~
r
-41
.4 t
-
-
1
4
44441-
11
-
-
T
-
-1
rr
-44- --
p--
4I4-
4
--
-
-14
-
-
1
444-
1
0.1
-:
4
5
7
A14
10
1.0
2
5
'
6
89
10
10.0
Final Aqueous HNO3 Normality
:-
3
4
5
6
7
8 9113
4~
37
The decrease in extractability is thought to be due to
the formation of nitro-nitrato complexes and/or lower
less than tetra-) nitrato complexes which are believed
to be less extractable than either the higher nitrato
complexes or the nitro species initially in solution.
In Figure 24 are plotted the values of E as a
function of final organic nitric acid concentbation for
aged (one month) RuNO-nitro complexes for a 24-hour
contacting time. By comparison with Figure 23, it can
be seen that for the salted solutions the rate of
increase of E0 with contacting time is greater than that
For instance, at a final
of the non-safted solutions.
organic HNO concentration of 0.060 M, the values of EA
for the non-salted solutions are 0.035 and 0.095 for A
the two-minute contacting and 24-hour contacting
respectively; a ratio of 2.71. The corresponding values
for the salted solutions are 0.066 and 0.340, or a ratio
of 5.15. This again is consistent with the previously
mentioned difference of rats of reaction and redistribution
between the RuNO-nitrato complexes and RuNO-nitro
complexes. This difference is shown more clearly iR
Figures 26 and 27. Figure 26 shows the values of E for
the non-salted aged RuNO-nitro complexes for the t
minute and 24-hour contacting times plotted so as to
enable comparison.0 Figure 27 shows the value of the
ratio (R) of the EA values at 24 hour contacting to the
EA values at 2 minute contacting as a function of final
organic HNO concentration for the a ed (one month)
RuNO-nitrat complexes and the aged (one month) RuNOnitro complexes. The organic phase nitric acid
concentration corresponding to an aqueous phase concentration of 3M HNO is marked for reference purposes.
It should be noted that since the RuNO-nitro complexes
are very slow (compared to the RuNO-nitrato complexes)
in approaching eqilibrium in the aqueous phase,
the aged
RuNO-nitro solutions will be labeled as to the length
of the aging time.
Whereas for the RuNO-nitrato
complexes there exists no appreciable difference in
solution composition at ages of one month or six months,
the RuNO-nitro complexes solutions appear to be changing
even at an age of four months. This topic will be
discussed in more detail in Section 3.3.1.
3.2.2 Effect of Aqueous Ruthenium Concentration
In Figure 28 are plotted the values of the final
organic ruthenium concentration as a function of final
aqueous ruthenium concentration for the RuNO-;nitro
complexes aged for two months. The aqueous ruthenium
concentrations were varied at two different levels of
acid concentrations. Both studies show the final organic
FIGURE 25
Extraction of Aged RuNO-Nitro Complexes
38
Solutions Aged For One Month at Room Temperature
24-Hour Contacting at 250 C With 0.26 M TLA in Toluene
0 = Nitric Acid System (No Salting)
A = Nitric Acid-Sodium Nitrate System (Total Nitrate=6.3M)
,
--
10
- -
-
8---
-
, -
--
- -+ -s-
9
-
--
---
-I
i
-
--
--
4
4-
A6
7 T h-
r
3
-
-
t4t
6
-
-----
-
* --
-
-L..
1
-
T,.
t
t
-
-4-
-
L
D_:
-
41'4
-.-
+-
4
Tn
1
1
-j
-4
-~~
--
2-
8-t-
:J
-
--
-1
p
-
TT
-t -
-f
-It
--
8
-
-
+
Lj - --
-
4-
-"-
r
-
- -
--
-
--
1-1
4
-
--
r!
_
-----
L
9j
If
-!-t1.
- - -
4
4
-m
-
-
-
1
- '-4-
4
1-
---- -
--
- -L
-
-
--
9
-~
-
t---
-
-
4
~-
4V
- --
-- -
-
-
44
24
..
w0
-- I
i- - t
rw
..j 0
X
L
r
-H
t71
4
-
7
7--
-+
-
Af
I tI
4VM-
r- t
r
I-
-
_
IT
T
5
t
T
-
--
-- 4-t
--
-
3
4-
4-i-
I.~t
-
--
2
f
t
131
4
---
-
.
..
+-
-
-
-
--
-3
4
6
/
8
o.010
2
Final Organic Unbound
-
3
4 1
6
11
v . 100 1
HIO3 Normality
2
9 1
23
4
5
6
7
3
4
5
6
7 a 9
8
10
39
FIGURE 26
The Effect of Contact Time on the Extraction
oLf RuNO-Nitro Complexes
Solutions Aged for One Month at Room Temperature
0.26M TLA in Toluene
A = 2 Minute Contacting at 20 C
0 = 24 Hour Contacting at 2) C
10
-
-
- --
--- ---
-
--
9
t
1
- -Tt
-
1
-
-
H
-
3
r
-
T
-4
-4--
--
t
10
7___-.----
1.
N
6
4
--
--.
_
-
_
T
_-
-
3 - 7------ - ---- -- - -- --*I--
1
--
1011
w
-
t+-1p
-
LLI
3
-
--
-
-
- -----------------
-*
-~
*
-7
'I
*~~-
.-
-
1
1
0.001
t
-
7
0."010
.0
Final Organic Unbound HNlO 3 Normality
2
--
3
4
5
6
7
8
9 10
FIGURE 27
40
The Effect of Contact Time on the Extraction of
RuNO-Nitro and RuNO Nitrato Complexes
Solutions Aged For One Month at Room Temperature
0.26 M TLA in Toluene
D
_
-
-
---
5'-
-
1
-
-t
-
--
-
,
-
-
3
-
-
-
J.
-
-
-
t
-
-
-
~~~ -
-+------
-
-
-
-
6
-
-4
77
-
-
4-
-1
-t
4-
'
--
-
-r-
4
-
-
-I
r.
;4 4
-+T
[aa
-4-T
104
-4-,-
-
--
0%
-P-
t
--
t
--
-
In
-7
1
--
-.
r-j
-
---
-
-
J
-----
IFF
-
___-
- --
----
+------------
2----
-1
t -
-
-
~- _
-
10
t-
-+
-
6
T
-
-i
-
4
6-
- -
_
-±--1-1
-7
7I
.
RuNO-Nitro Complexes
RuNO-Nitrato Com lexes
/.0
-,
04-
I I: I
I, 1:-
T-
-
I . -
a
.
I
-
1 ! , ,:.
-
-A
444
J
Em f
+4L
C
U
--
Ou
_je
5
0
T
--
-7--
X:-
-2-8-
----
-
--
-L
-
4-
-
k
%
-4--
-
-
i
-
~ ~~
-
--
T4
-
-
0
-1
-
t
-
-A
_4~-
-11
1
-
+i-
-
I
-
-3
~ 780.O
~
~
2
~ 345678 ~
~j
1110
Final Organic Unbound HNO3 Normality
-i-
2
T0 34567891
-
FIGURE 28
The Effect of Aqueous Ruthenium Concentration onExtrac tion.wrgRuNO@Nif oW1Aptes
1woi4SAU's at Room Temperature
Solutions Aged for
24-Hour Contacting at 2500 with 0.26 M TLA in Toluene
-
10
--t4
9
-
8
--
-rr
--
-
77,77~
r
~1
,
r~
-
4T
44
---
3
1-
-
-
-
-}
-
I__
4
-
i
- T
-
-,
-A
I
L-+J
7-T4T
H
---
4
uiI~
Q)-
'
T
4
-' +1-I-
t-
-
-
--
-I
~-
T
XZ
-~-
t
Nt
4
T
-_
-
-T_
t
-r l
-
-
2-
11
-
-t -
L~j
--
F
iT-
F
-- -
T1j
-
-
'
IA
f
t
I
1t
4
-
-1
-
1.
4-
-___ r
Lth
-
-I
--
-4
-
__ITI
- T -IT-K-T
Y
---
--
-T-F
~~
I
-- - - -1
~
8
T,
-
t
-~
--
-
L
44
t K~ :
-- L
-c--
-
1-:
-rT
-
Tj
-
1
7~
k
1
2-410
t
4
T~~j2"
r
-
4
6
7
T,02
--
-
T
t
-
---
-
t
t
6
4
3
6
T7
89
[.4
-
4 L.
-4-4-V-t---
T
4
~~
i
4
I.0
Final Aqueous Ru Conc. , gm/lit er
14-
t
{
.
--
r
-,-,-
4
U.10
-4-
--
tt
-
T-
4
--
_U
,VT
2
~-
. Ui
b
4
L
jjj~~
4
D
-
---
--
--
4
0
I
I[,,
-
I
~
---
-t-
-
4~
4
5
6
8
3
42
ruthenium concentration to be dependent upon the 1.2
power of the final aqueous ruthenium concentration in
the range of final aqueous ruthenium concentrations of
from about 0.2 gm/liter to 5 gm/liter. This dependence
upon a power greater than unity may be due to selfsalting of the RuNo-nitro complexes. A few extractions
with added amounts of sodium nitrite to RuNO-nitro complexes
will be -made in the near future to determine the effect
of nitrite
salting...
3.2.3
Effect of Amine Concentration
In a similar fashion to the aged RuNO-nitrato
complexes, the distribution ratio of aged (two-months)
RuNO-nitro complexes increases initially with the 1.2
power of the amine concentration and then tapers off to
a lower power dependence above an amine concentration
of approximately 0.13M. (see Figure 29) The tapering
off can again be explained by the higher concnetration
of unbound nitric acid in the organic phase than would
be the case if the ratio of unbound acid concentration
to amine concentration were constant.
3.2.4
Effect of Nitrate Salting
Following the method employed in Section 2.2.3,
the values of EO for 24 hour contacting of the aged
(one month) RuN6 -nitatejcmpexes are plotted in Figure
30 as a function of final organic unbound nitric acid
concentration for constant total aqueous nitrato concentrations of 1.2M, 3M, 5M, and 6.3M. Cross plotting 0
from Figure 30 gives Figure 31, where the values of EA
are plotted as a function of total aqueous nitrate
concentration for constant organic unbound acid concentrations.
From Figure 31, it appears that the distribution
ratio varies as the 0.8 to 4.7 power of the total aqueous
nitrate concentration. A particularly strong function
of total nitrate concentration seems to be apparent in
the small range of 5M to 6.3M total nitrate. However,
a was shown in Section 3.2.1, the rate of increase of
E with contacting time is greater for the salted solutions
(8.3M total nitrate) than for the non-salted solutions.
Therefore,0 in order to obtain a better idea of the
dependence of E on total aqueous nitrate concentration,
the dependence An conjact time should be eliminated as
much as possibl8 . This can be accomplished by plotting
the values of E for the two-minute contacting time.
Cross plotting grom Figure 23 yields Figure 32 which shows
the values of E A for two minute contacting of aged
solution at the non-salted conditions and the salted
43
FIGURE 29
The Effect of Amine Concentration on Extraction of
RuNO-Nitro Complexes
Solution Aged for Two Months at Room Temperature
24-Hour Contacting at 25 0 C with o.4N HNTO 3 Aqueous
Solution of RuNO-Nitro Complexes
L4,
*-
4L
6D-T
--
L-*
t:;zL,
5
~L
H94+-
r
44
T
--
_444
z
.5
I.
-
- 7
P!4-T;i
.
--
U
r
-r
n
.
t11
+;I
-r
-
j
Ib
qt
4
w
z z
$i1<1
+L--7T
7-
0
t,
t
~
--
-t
-
-1
-A
r
1
G
J
W
-
1K
U
2.s- .--
2
- 8'
nH
-25t-v
-
- ~
-F
-
-
+
----
5
-.
T
-_-_
TT
-T
-7
---
T
-1_
I
--
-
-
T
tT
4 -9
3I
4
.
-
A
W
-J
-1
-
-1 U
i
0 W
0 N
t
7-
-p
04
U
T:
2.
1
2v1
V-:
4122
j J
444-
--
iF>'LL~ j
.L 1 41 I
2.5
4
4-
-
.
I
t
4
.44iLL'
4
i
::I-i
5
4-i
I
Tin,
-
-:---!
I
-I-
-V
|.
.1
*1
1.
4.41.
|
T74
I
2
|
I -44.L
6
-T
I-.
I
4..'..
..
18
-
1 L ,
I
9
%.o
i '
1..L
1.5
I -
i
.. ,
,,,,.,,.,,,,.
2
Molarity of TLA in Toluene
I.
2:5
3a
.
4
5
6
7
8
9
10
OURE 30
The Effect of Sodium Nitrate Salting on Extraction
of RuNO-Nitro Complexes
Solutions Aged for Ong Month at Room Temperature
24-Hour Contacting at 25 C with 0.26 M TLA in Toluene
- -
J-
--
1A**4.
r-.. --.
- .
--
--
-
.
- -
,-r-
-
, ,-
1--
--
-
- *
-
H 4
1-
-
-
---
-
-
I -
--
-
---
4
-
-
--T
- t
-1
.
-
9-
-1
----
44
- - t -
-
-
~
-
,
.-
-
---
-- -A*f -'-
-
-I-
I
[
-
'
9--
--
---
L
lii
1WY
10
-
--
-
rtVt
0.001
K
-
--
-
-
-F- -1-- -1-
I-
ii.
11
L .1
11 1 iI
3
5
6
7
8
-
-
-- -
-
--
*1
4
-
ji
1L
-
-1 4--I -
-
410
0.010
-
I
--2
--
-4--
-
-
-
1
-
-
I
"-
I-;-
I'
-
-I
~
4
9- F
-T
-
-'.9-
PT
r
7T
-1
1 -4
'
-
--
---
t
~
-
-
4
I
-
-
-
-j
1~~
'1
-
Ii
-11
L1A
6 .3 7 8
1~
FVA
.4-
9 10
0.100
Final Organic Unbound HNO3 Normality
2
4
5
6
7
8 9 10
Figure 31
The Effect of Sodium Nitrate Salting; on Extraction
of RuNO-Nitro Complexes Solutions 6ged for One Month
24-Hour Contacting at 25 C with
0.26M TLA in Toluene
10
- -
-
-
-
10
i----.
-.
-
-
-
-
-
-
-
-
-
-
-
-
7~~A
-I
-
---
T
--
TT
T
-t--T -
-
__-
--
-
-
_I
44
r
--
-
14-
-
1
-
-t-
--
r
-
2
111
--
-
-
0-
--
-.
t-
-
94-
-
-
t
--
i-
-
S ]----
I
77'
+7
1
7
-
'I*-
*
-
*
-
-
r'
-
47
*
~4-
-
-
-
-- -__-t
-
-
-
4+
10
--
---
----
-
--
-
-
-
TT-
-
-
0
N
1
- -
-
4
-4
- - - - --
1-
-.
-
------
-
3
-1 0 x
w
O
4
..-..... --..
--
2.
-
--
-
-_
-
-
_
- -
-
-*
-
-
-
~**
T
---
--
-
-.
-L
q01
0
1
-
-
-
-
7
--+
Final Aqueous Total Nitrate Molarity
8
-
--
+
-4-
44
Figure 32
The Effect of Sodium Nitrate Salting on
Extraction of RuNO-Nitro Complexes
2-Minute Contacting of One Month
Aged Solutions at 25 0 C with 0.26m TLA
10
-
-
8-
-.
-
-
-.
-
-4
4
--
4---
---
1---
-
tt__
6
----
-
4
--
- --
-
-
---
--
-
-4L
2
3
--
+
----
-
-
-
-
~2-4L --
-- ~~'
-
-
-
------
-
-
4--
--
---
-
-
-
-
--
7-
--
H
-
f --
---
*--
1
-
-
.
7 ~ T<± -
+- -
- -- -
10
-- - -- >---
10
t
- - -
-
--
-
- -
4
.4-
3y
6
-
- r -
--
-
-
_
-
-
a1
T
--
44
-
-
I
-
* --
--4r
L
, ---
-
-t
-
- H--
-
- - -- - -
-A
-
-
-
-
~
-
--
tt
-
-
---
6
,-4----- -
---.-
-
-a-,1-'-
---
- ---
--
S-r
-
--
-- - -
-
40
t
3
-
-
--
-
-
--
-
-1
.-
2
t
-
-i
2
--
-
1
A~~~~
3.
- -,-
--
-
22--
J
--
-
-
4-
5
T4
4
--
-
-
-
-
--
-
-4-
-
.0s?4
-
-
1
I
__iIIF
1q4
4jk
4
5
Final Aqueous Total Nitrate Molarity
3
4
5
6
7 8910
-'
---
-
47
condition of 6.3M total aqueous nitrato concentration.
The values of EA for the intermediate salted solutions
are not plotte because those data points were taken only
for the 24 hour contacting time and not for the two
minute contacting time.
From Figure 32, the value of EA is seen to be
dependent upon the 0.4 to 0.8 power of the total aqueous
nitrate concentration. The actual exponent is probably
closer to 0.4 than 0.8, since the slope of 0.8 is a
result of two closely spaced points and a small error
in their values could result in a large error in the
slope of the line drawn through them.
3.3
Spectra of Solutions
Spectra of the RuNO-nitro complexes solutions were
made on a Beckman Model Du Spectrophotometer in order to
discover any similarities and/or differences between
these solutions and the RuNO-nitrato complexes solutions.
3.3.1
Effect of Solution Age
'As a means of determining the length of aging time
required for the RuNO-nitro complexes to come to equilibrium
in aqueous nitric acid solutions, spectra were made of
three RuNO-nitro complexes solutions at aging times of
seven weeks and four months. The spectra are shown plotted
in Figure 33.
Several points are of interest:
(1) The spectra of the RuNO-nitro complexes at both
solution ages are similar to the aged RuNO-nitrato
complexes from the aspect of exhibiting a minimum in the
value of the absorbance between 400 mp and 450 ms and a
They are also
maximum betwe!i 450 ms and 500 m.
similar in that the absorbance at the maximum increases
with increasing nitric acid concentration.
(2) A significant difference is that the position
of the maximum shifts with acid concentration. Whereas
in the aged RuNO-nitrato complexes solutions the maximum
remained at 475 mi, in the seven weeks aged RuNO-nitro
solutions the position of the maximum moves from 485 mP
at 1.2N HNO to 500 mp at 9.6 N HNO . Although the
absorbance at the maximum increases3 with acid strength,
it does not increase nearly so much as does the peak
absorbance for the aged RuNO-nitrato solutions.
At the seven weeks aging time, the absorbance
(3)
minimum for the RuNO-nitro solutions is much more
Fm e 3
44T
-_
,,
.
I
._
_. 1
i
-
t
-
I
12 -ty~-
4
tt
-
--.
--
------
4r
t
-
-
-
+---
----
---- L-- +-
-
-
-
A-
-r--
-
_
1
-
-;--
4
-- 1e-
4-
t
T
1t
t
.
-
--
.
-T
-
-
-i
-
1
A-
-
-
-
-
-------
~
+
T
-
-
-
-
-~
-
t+
--
i-
-1---
2
L
L{
4
1
4
44
i
4-
1
4
-
t
;
-
-
tt
~-
4>4
--
-
---
--
-
-
-
~
-
-
-
- '-
-
---
.
;
4
1
-4
14
,
4
-
t1
,
-
---
--
--
-4---
--
---
r-
--
---
T
-t-
-
-
-
4 - -
-
- --
-
*T -H
4
T
2- -
--
+
-
-
-
-
- -
-
-
--
- - -
- - -
-
T4-
-
-
-
I
4iFt
- -
-
-
-
-
--
-
---
+
-+
T
* -
-
+L
--
41
S-'r
-
--
- + --i -+
4
_
1
- -' -
-
I
-
-
--
:
t
-4-
-. t
7
Lr-.
I
L
77L
Ll
-
-
-IrtL
4
L
4-i
4
- +4r-
1
-
-4
I
71
T
1-14
-
-
-
TT-
i4*
4
or
t
'
i
14
r
--
- +-
-T
-
+
-
-
.-
-LL
.1
--
-
-
-NN
I
IIi4
{7
4-
t
-t4
-
-
T
-
IT
.
t
L
t
.
~
t
49
pronounced, especially at higher acid concentrations,
than for the RuNO-nitrato solutions. A large shift in
both position and absorbance of the minimum is seen
between 1.2N 1N0 and 4.5N HNO but practically no
difference in either position dr absorbance is observed
between 4.5N HNO3 and 9.6N
HNO 3 '
(4) The effect of aging is generally to increase
the absorbance over the entire range of 400 mp to 540 ms
(except for the 1.2N HNO solution above 420 mW) and to
shift the position of thd maximum to lower values of wavelength. Little effect of aging is observed for the 1.2N
HNO solution, but a large effect of aging is seen in
the 4.5N HNO and 9.6N HNO solutions. In the latter
two cases, tAe spectra are3 seen to be changing so as to
more nearly approximate the spectra of the RuNO-nitrato
complexes solutions. The position of the maximum for the
4.5N HNO solution has shifted to about 475 mpL, the
same as for the RuNO-nitrato complexes, and the position
of the maximum for the 9.6N HNO solution has shifted
from about 500 m4p to about 485
-p.The absorbance
maximum in the 1.2N HNO solution appears to have shifted
from 485 fl to about 47; mp, but the value of the
absorbance at wavelengths greater than 470 m appears
to have decreased. However, the change in the spectrum
of the 1.2 N HNO solution has been litle. and its
interpretation m st be somewhat limite'.
The general conclusions to be reached are:
(1) that the RuNO-nitro complexes solutions are very slow
in attaining equilibrium(relative to the RuNO-nitrato
complexes solutions.) Equilibrium has not been reached
after seven weeks aging and possiblynnot after four
months aging; however, more spectra will have to be taken
as aging continues before the latter statement can be
shown to be true or not.
(2) From the appearance of the manner of the change in
the spectra with solution aging, it appears that the
RuNO-nitro complexes are slowly being transformed,
either wholly or in part, to the RuNO-nitrato complexes
and/or mixed RuNO-nitro-nitrato complexes. This conclusion
is consistent with the conclusion drawn from the extraction
studies on the RuNO-nitro and RuNO-nitrato complexes.
3.3.2
Effect of Ruthenium Concentration
In Section 3.2.2, the value of E0 for the aged(two
months) RuNO-nitro complexes was foun& to be dependent
upon the 1.2 power of the aqueous ruthenium concentration.
Although this effect is believed due to self-salting of
50
the RuNO-nitro complexes, a series of spectra
measurements was performed to determine if the spectra
changed as a function of aqueous ruthenium concentration.
The measurene nts were made on 1.2N HNO3 solutions
of RuNO-nitro complexes. This solution was chosen
for two reasons:
(1) The spectra of the 1.2N HNO solution changes
very little with solution age (see Fiure 33).
(2) The value of 1.2N HNO falls within the range
of acid concentrations that dis layed the dependence of
the value of E? on the 1.2 power of aqueous ruthenium
concentration tsee Figure 28).
Figure 34 shows the spectra for 1.2N-HNO3 solutions
with aqueous ruthenium concentrations of 0.22, 0.44,
1.09, and 2.17 gm/liter.
The solution had been diluted
from the original stock solution concentration of 5.43
gm/liter with 1.2N HNO after the stock solution had aged
for two months. The diluted solutions were aged for two
weeks before the extractions were made and the spectra
taken. The spectra appear to be very regular with
regard to one another and do not display any noticeable
variations other than the expected decrease of absorbance
with decreasing ruthenium concentration. In fact, the
value of the absorbance at the maximum (48Omp) varies
linearly with concentration as shown by Figure 34. Visual
inspection of Figure 34 shows that the linearity holds
true at the lowest wavelength measured (400 mu.), the
highest wavelength measured (540mp), and at the position
of the minimum (440 m).
Although the regularity of the spectra cannot be
considered proof of a lack of effect of ruthenium
concentration on the amount and/or type of RuNO-nitro
complexes in solution, i would indicted that the
observed dependence of E on the 1.2 power of the
ruthenium concentration is probably due to the effect
of self-salting.
FIGURE 34
4
-
~
v
___
.
..~:
4
+
%-44
=
T
~-t
--
'1
--
r
I
-44
+
-r
1y
- --
-4-
-'-
- - i
+
t
T,
1
L...4.
.200
~~~~~-f
-~
-----
~
A
L
1.000
+
4
4!
4
1 .11
'
1
T4
t
-
I L
-4t
~ --
-
-
o.8oo
~4
r-
41
-4
-
r-
-*t
+
-j*----
----1-
-
-
-
-1
qt,4
,
.;
-
-L
.
-
-
4
-
-
-
-
-
-
-
1
-
*
4-
-
-
-
-
-
.
44
-4
r
4
-
-
7
-
0.600
44
t7
7
iI "'
-
--
L
-- I
--
-
.A
---
*t
-
-
--
---
--+ ---
A
--
-
1
-----------1-----
--------------------------
t----t---
20 200
-IF-
1
T
-
--
--
-
-
-
-
-
0.000
I
-
-
-
-7-
L9--
-4
~
7 '
-
7-
_-
-
%
\
1avo1cn't h,
4- -
44
---
--
'
-
--
T
"
-
*
t
' It
- ---
--
4T
-
-
-
T
-*-+---
-4---
t
mp4
-L1
--
--
FIGURE 35
--- -
-t
-
I --
. .-
-
- -
----
-
,
-
--
-
-4-
4
-
131-
- -
4-
T
r
t----+
-4- 4~
i
t
i
-
4
t
- --
-
n-- t --
4
-4
~
r
-
4
- 41-
TT
-{
-
- -
-- -
--
-
I--
-
i
4----
ii
+
u,
-
44
I
I
-
+ ---
----
+ -
-
-
4
--
4-
4
- -..
- - --
+
-
_
--
.
-
-
-
-__-H-
-
4-
4
1-
-
-
4 44
r
W
- -
-
-t
tT
TT
--
-
-
4-I4
-4
4
4
4r-
-
-
7
~44
0'7
T -4
Th-
----
44-
-44T
1
-
-
-~
-4
77
.
t-
-
t
J
-
--
-
4
4
4
4
T
T
,
L
-H
--
-
-
4
4
i - 5_
r
+-4
1 T_
I,
14
- -+-
i
t
- u~ -
1
t
t ~ ~~
-
4
-
4;1
p
-
t-
-
4
4
-
u.- A
z
4
L
2-
-4
'
-
i
t
-_
_4
-
-
-
--
'--l
4
'
-
--
-
4-
0
-4
tt
-
-C
4
4
'-4
---
-
-4--1
141
114-'
7
7
E-11
7,
_4m
f-4'
4
4
-
I
4
rl
-
TT
fit
-4
4
-
I-
-If
4
.44
4441
_
L
--_
--
-
Y
1
44
444-4
44
'4
1<44t'l
':
2',4
-4'4-4'''" <~~T
1
44
4
-
4
-
-4
T
44
-
t
1
'-
H'4-
___
4'
4I-
4 t-
TABLE 3
Summary of Ruthenium Extraction Data
Aqueous
Sample Type
of
No.
Complex
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
NO
Contact
Age
of
Time
Temp0 C
Soln.
2m
25
"t
it
"t
it
"
"I
it
It
"t
"t
"
"
It
I
2m
"
11
"
"I
f
"f
I
it
I"
2m
"t
if
"I
"1
"t
"
"t
"'
"t
"
"t
"
"t
"t
"t
"t
"
1.27
3.10
6.13
6.12
"I
5.05
1.21
3.05
"t
0.52
"t
"t
"I
"
"
"
"
It
"t
"
"I
"t
"t
"
"t
"t
"t
"
1.196 1.196
4.31
0.47
"
"I
2.938
4.51
6.29
8.22
"
"
"t
1.219
2.60
"I
"t
0.755 0.755
it
"
"
"
0.403 0.403
0.766
9.60
0.358
1.006
"t
"
0.421
2.93
4.48
6.24
8.11
9.56
6.29
6.20
6.28
6.53
6.18
if
Organic
TLA,M
Final
Ru, gm/l
0
EA
3
2.93
4.48
6.24
8.11
9.56
0.307
0.947
2.55
4.26
0.45
"
NA
Initial Final Final Initial
HNO
ENO3 Total Ru,gm/l
3
NO
0.89
1.32
3.10
4.91
6.85
8.74
10.08
0.42
4.98
0.49
0.87
6.28
0.49
0.87
1.31
1.31
4.92
4.92
3.07
3.07
6.86
8.84
6.86
8.84
10.19 10.19
0.41 0.41
5.43
I"
"t
"t
0.25
It
I"
It
"
"t
It
"
"t
"
4.94
"
"t
"t
6I.o
If
6.00
it
0.25
if"
it
6.45
"I
"t
"t
it
it
it
"t
"t
"
"t
"t
"4
"
"t
5.43
"1
0.77
0.77
0.77
".I
It
1.21
"
"
2.94
4.51
3.20
3.20
"
"t
1.22
1.21
4.59
4.59
"t
0.954
0.742
0.582
O.205
0075
0.0276
0.02
0.02
0.480
0.240
0.114
o.048
0.146
0.0796
o.03 54
0.0301
0.0303
0.0324
0.0328
0.0364
0.0285
0.0224
0.0183
0.018
0.487
0.345
0.217
0.0944
0.0472
0.212
0.158
0.120
0.0382
0.0140
0.0051
0.0037
0.0037
0.1076
0.0511
0.0236
0.0098
0.0249
0.0134
0.0060
0.0050
0.0047
0.0050
0.0051
0.0057
0.0044
0.0035
0.0028
0.0028
0.0986
0.0679
0.0417
0.0177
0.0088
LA3
Sample Type
of
No.
Complex
-
71
72
73
74
75
76
77
78
79
NO
"
"I
"
"
if
"
"
"I
"
"t
"t
"
-"
83
84
85
86
87
88
89
90
91
"
92
It
93
94
95
96
"I
"
hrs.
24
11
it
it
"t
"
"t
"I
"
"t
"
"I
"
"
"
"t
"I
"t
"
"I
"
"
"I
6.29
8.22
9.60
0.36
1.01
2.60
4.31
"I
"t
"I
6.42
8.16
9.81
0.31
0.96
2.59
4.38
6.42
8.16
9.81
6.29
6.21
6.32
6.65
0.42
0.41
0.41
0-.77
0.77
0.77
2.94
4.51
2.98
4.34
5.98
8.21
9.74
2.98
4.34
5.98
1.22
6.29
8.22
9.60
0.42
0.41
0.38
0.36
1-16
1.07
1.01
"I
"I
"
i
i
I
I
i
i
2.60
"t
"I
25
"
"
"
nM.
2.97
2.76
"1
"I
"
100
101
"t
"
"
Organic
Initial
TLA,M
Final
Ru,gm/l
0
A
it
0.0216
0.0125
0.0140
0.155
0.0040
0.0023
0.0026
0.0752
0.0324
0.0302
1.50
1.03
0.0061
0.382
0.234
Ru, gm/l
3
"I
"
99
Contact
Time Temp0 C
A
I
It
"t
80
81
82
9T
Age
of
Soln.
T4BLE 3 (cont.)
Aqueous
Initial Final
Final
Total
HNO
HNO
3
3
NO
4.60
4.31
0.42
0.42
0.42
0.42
1.21
0.41
0.36
0.33
0.26
1.13
0.95
0.91
2.57
2.77
2.55
4.65
4.38
0.41
0.41
o.4o
0.40
1.21
8.21
9.74
0.99
2.94
4.91
6.24
2.91
4.73
6.16
2.67
4.87
6.28
5.15
6.65
5.43
0.41
0.40
0.40
11
5.43
i
0.25
4.94
11
I"
it
it
I"
"f
it
5.43
f
I"
I
it
"I
"
"I
"
0.345
0.0767
o.650
0.149
0.0541
"it
i
It
0.0251
0.0141
11
"
"
0.0104
"
"t
"
"I
1.23
1.19
"I
1.33
4.94
"I
5.43
it
"t
it
4.94
5.43
4.94
5.43
2.17
1.09
0.435
0.515
0.449
o.615
0.139
0.136
0.0282
0.0101
0.0041
0.0026
0.0019
0.293
0.281
0.324
0.488
0.105
"
0.123
0.0902
0.142
0.0263
0.0232
"t
o.180
0.045
0.0378
"t
"t
0.0406
"t
1.415
0.0083
0.353
0.525
0.235
0.320
"
4.94
5.43
1.62
0.0160
"
"
0.0831
0.0084
0.277
0.236
TABLE 3 (cont.)
Sample
No.
102
103
104
105
106
107
108
109
110
111
Type
of
Complex
Age
of'
Soln.
f
At
If
if
"
"
ft
Nt
"t
"t
"t
"t
"
NO
t
Contact
Time
A
24 Hrs.
ft
t
t
if
"I"
"t
t
it
2m
112
"t
if
113
114
115
116
117
118
119
120
"t
It
"t
it
"t
It
"
it
"
"t
Ift
"t
If
"t
ft
"t
if
"t
It
"t
"t
"f
24 ir.
121
122
123
"t
"1
it
"t
124
125
126
it
ift
"t
ft"t
127
128
129
"t
130
131
132
"t
133
134
135
136
137
If
"
"t
it
ft
It
11
"t
it
If
"t
"
It
1t
If
"I
if
"t
ift
"t
"t
it
ft
"t
"t
"t
1t
"t
"t
"
"t
"t
"t
It
t
it
"
it
if
26
t
it
f
It
t
f
t
t
if
it
if
"t
"t
Temp0 C
"t
"t
"t
"t
"t
it
1t
1t
"t
"t
"t
It
HNO3
Aqueous
Final
HNO3
Final
Total
Initial
Ru, gm/i
Organic
TLA,M Final
Ru, gm/i
0
EA
0.03tib
0.217
NO3
"i
NA
Initial
2m
"
"
"t
0.42
0.41
o.42
0.42
0-42
0.41
0.42
1.22
1.22
1.22
1.22
1.22
1.21
0.47
0.44
1.27
3.10
5.05
3.10
4.91
3.09
0.44
1.21
1.20
1.19
1.19
1.21
3.02
4.99
3.04
4.90
3.03
0. 41
0.217
0.41
0.42
0.44
1.21
1.21
1.20
1.19
1.19
6.17
6.13
0.25
5.43
5.43'
5.43
5.43
0.20
0.125
2.17
1.09
f
it
6.09
6.29
3.04
4.90
4.94
3.10
5.05
1.32
1.27
1.29
1.27
3.02
5.01
1.31
1.21
1.18
1.16
0.52
0.50
0.48
0.46
0.47
0.49
0.48
1.32
1.32
1.32
1.32
1.32
1.32
0.52
1.31
1.32
1.32
1.31
0.49
1.20
3.20
5.26
6.10
1.31
1.32
1.32
1.31
1.33
1.33
0:89
1.32
0.40
0.35
0.37
1.32
0.49
0.82
1.31
6.09
6.31
1.31
3.10
5.07
6.08
1.32
0.49
0.82
1.31
0.435
0.05
0.25
it
0.217
6.00
6.00
"t
6.oo
"t
6.00
"
6.45
6.45
6.45
6.oo
6.oo
6.45
6.45
6.45
6.00
6.45
6.45
6.45
6.45
"f
"t
"t
it
"t
"t
"
"t
"t
"t
it
"t
0.20
0.125
0.05
0.08
if
0.06
0.25
it
"it
it
"f
0.847
0.313
0.631
0.212
0.105
0.0323
0.0154
0.154
0.069
0.040
0.035
0.364
o.164
0.337
0.307
0.117
0.502
0.848
0.969
0.987
0.266
0.709
1.70
2.51
6.00
6.45.
6.45
6.45
6.45
t
1.195
2.38
0.430
0.265
0.074
0.197
0.143
0.095
0.09
0.019
0.025
0.282
0.185
0.0612
0.127
0.108
-
0.107
0.080
0.076
0.0264
0.0116
0.0067
0.0059
0.0600
0.0261
0.0552
0.0540
0.0200
0.0844
0.151
0.177
0.197
0.043
0.124
0.358
0.637
0.657
0.0714
0.0428
0.0116
0.0315
0.0227
0.0150
8:880
0.0039
U1
u,
TABLE 3 (Cont.)
Organic
Aqueous
Sample
No.
138
139
140
Type
of
Complex
NA
I
it
Age
of'
Soln.
A
I
t
Contact
Time
Temp .0 C
Initial
HNO3
Final
HNO3
Final
Total
NO
Initial
Ru,gm/l
TLA,M
3.02
6.45
"t
0.25
Final
Ru, gm/l
Eo
A
3
2m
"t
"
26
It
I"
3.10
4.91
6.85
3.02
4.82
6.71
4.82
6.71
"
"1
i"
0.049
0.045
0.035
0.0039
0.0070
0.0055
4.0
Uranium Extraction
Mr. David Sabo worked on the project as a Research
Assistant for two months in the Summer, 1961, to
investigate the effect of tempexdperature, sulfate ion,
and fluoride ion on the extraction of uranium.
Effect of Temperature
4.1
A brief study of the effect of temperature upon
uranium extgaction consistea of five parallel samples,
three at 25 C and two at 50 C. The results are lided
in Table 4 and plotted in Figure 36.
TABLE 4
Uranium Temperature Study
Aqueous
nitrate
Organic
Contact
Phase =
in 5.8N
Phase =
time =
4.88 gm/liter of uranium as uranyl
HNO solution.
O.O6M TA in toluene
24 hours
Sample No. Temperature, UC
Final Ag.
HNOal
tA.
/l
Final Org.
U
o
1
25
--
3.72
0.953
0.256
2
25
5.60
3.88
0.883
0.227
3
4
25
50
5.76
5.73
3.84
4.25
0.946
0.661
0.247
0.163
5
50
5.75
4.00
0.643
0.163
It was found that a 33% decrease in the value of
the distribution gatio regulted when the temperature was
increased from 25 C to 50 C. This corresponds to an
3.10 Kcal
activation energy of AH =
=mole*
4.2
Effect of Sulfate
In order to study the effect of sulfate on uranium
extraction in nitrate systems, solutions of uranyl
nitrate were made such that the nitric acid and total
nitrate concentrations remained at 2M, while the sulfate
concentration (as sodium sulfate) varied in steps of 0.5M,
1.OM, and 2.OM. The data are listed in Table 5 and shown
plotted in Figure 37.
58
Figure 36
-a'0
--
f
TTT
W7.
e
i t-
x
0
u *2
I
I)
IL
i
1131
--
-
-
j_
___-V&
-
__
1-.C
__lt
--.--.--- I
_
-L-
_
-----
-
-'
S
_
__
100
_
t
_
359-73
KEFFEL & SSER CO.
A9L'N,
140 DIVIS ONS
CYCLES
SEF [LOGARITHMIC
HO
_
__I
_
--.
t--
,..- ----..-.
C
-
_-_
-
.- -...-.-.....
--
-
t
1_ -
-
___C
__
-~-
___
-_
_ _
__
...-.-.- .-.
4
_
7-7
t__
.-... .--.--...-
-___
- --
r7
- ----..
------
0
TABLE 5
Uranium - Sulfate Study
Aqueous Phase:
HNO3 = total nitrate = 2M
Contact time = 24 hours at 2500
Organic Phase= 0.086 M TLA in toluene
gm/liter
U org,
U aq., f
Sulfate,M U aq.,i
0,0
0.5
1.0
2.0
4.47
4.63
4.60
4.44
4.89
4.92
4.74
4.67
f
EA
0.376
o.0841
0.232
0.136
0.0501
0.0296
0.232
0.0523
The addition of sulfate is seen not to affect uranium
extraction by any order of magnitude, but may possibly
affect it by a factar of two or three.
Effect of Fluoride
4.3
Parallel solutions of fluoride, similar to the
sulfate solutions, were prepared, using ammonium fluoride
as the source of fluoride ion. The data are listed in
Table 6 and plotted in Figure 37.
TABLE 6
Uranium - Fluoride Study
Aqueous Phase: HNO = total nitrate = 2M
Organic Phase: 0.086M TLA in toluene
Contact time : 24 hours at 250 C
Uaq.,i,gm/l
Uaq. , f
Uorg,f
0
EA
4.47
4.19
0.376
0.0841
0.221
1.0
4.89
4.43
4.63
0.385
2.0
4.52
4.24
4.21
0.0530
0.0908
0.0741
Fluoride,M
0.0
0.5
0.312
Similar to the sulfate addition, the addition of
fluoride does not affect uranium extraction by an order
of magnitude, but may possibly affect it by a factor of
two or three, In the sulfate and fluoride cases, a
more careful and detailed study would be required to
determine their exact effect on uranium extraction.
62.
5.0 References
(1) Mason, E.A., and Skavdahl, R.E., "Equilibrium
Extraction Characteristics of Alkyl Amines and
Nuclear Fuels Metals in Nitrate Systems," Progress
Report VII, M.I.T. Nuclear Engineering Department,
November 1, 1960. Also released as TID-11196.
(2) Mason, E.A., and Skavdahl, R.E., "Equilibrium
Extraction Characteristics of Alkyl Amines and Nuclear
Fuels Metals in Nitrate Systems," Progress Report
VIII, M.I.T. Nuclear Engineering Department, May 1,
1961. Also released as TID-12848.
(3)
Mason, E.A., and Skavdahl, R.E., "Equilibrium
Extraction Characteristics of Alkyl Amines and
Nuclear Fuels Metals in Nitrate Systems," Progress
Report IX, M.I.T. Nuclear Engineering Department,
August 1, 1961.
(4)
Fletcher, J.M., et al, "Nitrosylruthenium Nitrato
Complexes In Aqueous Nitric Acid," Journal of
Inorganic and Nuclear Chemistry, Vol. 12, pp.
154-73.
(1959)
(5) Brown, P.G.M. Fletcher, J.M. Wain, A.G.,
AERE-C/R-2260 (1957)
(6)
Brown, P.G.M., "Nitro Complexes of Nitrosylrutheniums"
Journal of Inorganic and Nuclear Chemistry, Vol. 13,
pp. 73-83 (1960).
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