ORNL-1771 - Oak Ridge National Laboratory

ANHYDROUS
HYDROGEN FLUORIDF I.---
PERIOD ENDlNG SEPTEMBER 70, 1954
M MONEL NEEDLE VALVFS
@ MONEL BELLOWS VAI>/FS
UNCLASSIFIED
OHNL-1.H-DWS 1724
20 % KOH
SODA-LIME TRAP
Fig. 10.1. Apparatus far ~ ~ ~ ~ of r Oxygen ~ i ~ in Fluoride ~ t i SoJts. a ~
measurements are carried out in a 25-ml fluorothene
cell fitted with platinized platinum electrodes.
The reaction vessel, a modified Parr bomb, is
silver plated on the inner surfaces, as are the
lines and the fittings in the reactor-conductivity
cell section.
In the procedure now being tested the sample is
placed in the reaction vessel and the system is
evacuated to valve 5 (see Fig. 10.1). After the
cell has been filled with a measured volume of
the distillate, the conductivity is measured and
the acid is transferred to the reaction vessel by
distillation. When the oxides have keen converted
to water, the solution of water in hydrofluoric
acid is distilled to the cell where the measurement
of conductivity is made. Transfers of the acid
are repeated until constant readings are obtained.
The distillation apparatus has been tested and
has been found to deliver anhydrous acid at a rate
sufficient to fiIJ the cell in less than 1 min, When
the still was charged with 99% HF, the conduc-
tivity of the distillate corresponded to a maximum
concentration of water of approximately 1 ppm.
Weighed samples of anhydrous LiOH are being
taken through the procedure outlined above as Q
means of calibrating the apparatus. Calibration
measurements have been completed over the range
0.03 to 0.25% H,O in HF,
149