relation between the ratio of activities and the ratio of mass before and after leaching. The
ratio of the weight of solid remaining after leaching to the original weight was 48 per cent,
whereas the ratio of the activity in the leached solid to the total activity of the solid before
leaching was 54 per cent.
Table 4.2 —X-RAY-DIFFRACTION ANALYSIS OF RADIOACTIVE
PARTICLES REMOVED FROM THE DIFFERENTIAL
FALL-OUT COLLECTORS
Station
Compounds present
Janet
CaCO; (calcite)
CaCO;y (artificial calcite)
Compounds
probably present
Remarks
Ca(OH), (Portlandite)
CaCO, (aragonite)
Wilma
CaCO, (aragonite)
Amount of sample less
than 1 mg; identity of
compound not certain
540.16
CaCQ, (calcite)
Unknown compounds of
See Station 540.18
540.18
CaCO, (calcite)
Unknown compoundsof
The unknown compounds
CaCO, (artificial calcite)
CaCO, (artificial calcite)
Ca(OH), (Portlandite)
large lattice spacings
large lattice spacings
CaCO, (aragonite)
remarks
of large lattice spacings
are not all the same;
preliminary determina-
NaCl(halite)
tions have shown them to
be the less common com-
pounds; further research
is needed to determine
their nature
540.13
Ca(OH), (Portlandite)
CaCO, (calcite)
NaCl (halite)
CaCO; (artificial calcite)
540.14
CaCO, (calcite)
CaCO, (artificial calcite)
MgO (pericilase)
$40.09
Unknown compounds of
See Station 540,18
CaCO, (aragonite)
Amountof sample less
large lattice spacings
remarks
than 1 mg; identity of
compound not certain
The liquid from the total collector located at Station 540.18 was analyzed to determine the
percentage of activity from ions and that from colloids. This analysis was done by ultrafiltration at 38 atm through a cellophane dialyzing membrane with a pore size in the range of 12 to
40 A, It was found that 71 + 3 per cent of the activity was associated with the ionic species and
29 + 4 per cent with the colloids, Since this liquid sample had been previously filtered through
Whatman No. 30 paper, someof the colloids remained with the particulate caught by thefilter.
40