ORNL-1771 - Oak Ridge National Laboratory

ANP QUARTERLY PROGRESS REPORT
CH EMlSTRY OF Ab. K ALI-hi %TAL HY D RBXIDES Reactions of copper and nickel with sodium hy-
L. G. Overholser F. Kertesz
droxide were previously investigated by determining
Materials Chemistry Division the equi librium hydrogen pressures developed.
Pur i fie at i QW
Monel, an alloy composed primarily of copper and
nickel, has now been investigated by this method,
E. E. Ketchen
The Monel reaction tube containing the melt was
Materials Chemistry Division surrounded by a quartz envelope, to which was
Eighteen batches of NaOH were purified by filtering
the 50 wt '% aqueous solution through a fine
sintered-glass filter to remove the Na,CO, and by
attached a manometer far determination of the
hydrogen pressure. Establishment of equilibrium
required long periods of time, and the values obtained
were not completely reproducible, Therefore,
only a range of equilibrium pressures is presented
dehydration at 4QQOC under vacuum. Approximately
one-half the runs yielded products containing less
thcrn 0.1 wt %I H20 and 0.1 wt 76 Na,CO,. The
remaining runs yielded less than 0.1 wt % H,O, but
the values for Na2C0, ranged fromO. 11 to 0.2 wt %.
Four 0.5-lb portions of potassium were reacted
with water, and the resulting solutions of KQH were
dehydrated at 400'C under vacuum. The resulting
material contained less than 0.1 wt '% K,CO, 0.1
wt % H,O, and approximately 0,l wt % Na,
Reaction of Sodium Hydroxide with Metals
H. J. Buttrum F. A. Knox
F. Kertesz
Materials Chemistry Division
Work has been continued on the reaction of copper
and sodium hydroxide. Data were previously re
ported33 on copper concentrations found in NoOH
up to 8OOOC. A recent deteimination at 900°C
shows 2500 pprii Cu in the melt after exposure.
This value is higher than would be expected from
the previous datu taken from 600 to 8OOOC. A plot
of lag Cu concentration vs 1/T yields a straight
line from 600 to 8OOOC and thus suggests that true
equi librium values were obtained. Extension of
this line would give a value of about 1500 ppm
rather than the 2500 ppm Cu obtained.
33F. A. Knox, H, J. Buttram, F. Kertesz, ANP Quar.
Prog. Rep. June 10, 1954, ORNL-1729, p 60.
80
in the following for the sodium hydroxide-Monel
reaction:
Temperature ("C) Pressure (mrn t-lg)
600 35 to 42
700 112 to 130
800 160 to 193
9 00 232 to 280
1000 280 to 360
In another series of tests nickel oxide (reagent-
grade commercial material heuted to 7OOOC in
vacuum) was added to sodium hydroxide in a jacketed
nickel tube, At 350OC a pressure of 22 mm Hg was
found. Mass spectrographic analysis of the gas
revealed 5.6% hydrogen and the remainder to be
essentially water vapor. The temperature of the
test was increased to 500OC and then, in l0OT
increments, to 1000°C. The pressure in no case
exceeded 31 mrn Hg, which is approximately the
saturated ambient water-vapor pressure. Analyses
of the gas showed it to be 97 to 98% water vapor,
with a little hydrogen, Under otherwise identical
test conditions, no water vapor was found when
nickel oxide was omitted. The net effect of the
nickel oxide is apparently that of oxidizing the
hydrogen formed from the Ni-NuOH reaction to water
vapor.