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Amount of flux and sample to use
Today’s market has seen a proliferation of various mold diameters. Consequently,
one must adapt the amount of flux and sample to obtain a full disk that will not
overflow out of the mold.
Our recommendation is to measure the actual inner diameter on the bottom of
the mold and apply the following formula, to obtain the total mass of sample and
flux:
Total mass [g] =
(Mold diameter [mm])²
150
Thus, for a 32-mm inner diameter mold (recommended diameter), we obtain
32² / 150 = 6.827 g, which we can round up to 7 g.
This being said, there are also molds on the market that are very shallow (despite
the thickness of the metal they are made of). Those molds will require less flux to
fill correctly, but leveling of the mold is more critical.
Flux-to-sample ratio
After the choice of the right flux, the flux-to-sample ratio is probably the second
hardest question to answer. This section intends only to explain general concepts.
For more specific information, the customer is invited to contact Katanax directly.
To obtain the best readability possible on the analytical instrument, one wishes to
put as much sample as possible in the preparation. However, putting too much
sample will over-saturate the flux, and leave undissolved sample particles in the
disk.
The solubility of samples into the flux being rather hard to predict theoretically, it
is recommended to work with the following method:
1.
Determine the optimal flux type. If unsure, 67% LiT with 33% LiM is a good
starting point.
2.
Using the formula above, calculate the total amount of flux and sample
required for your mold size.
3.
From this mass: weigh 5% sample for 95% flux, directly in the crucible. Mix
thoroughly.
4.
Proceed with fusion, and observe the result.
5.
If the bead is perfectly homogenous, it is possible to try increasing the amount
of sample a little.
6.
If the bead is milky or dusty (presents tiny particles of undissolved sample),
try again with less sample, or change the flux type a little. It is also possible
that the sample be not completely oxidized. Just after weighing the sample
(before adding the flux), add a small amount of solid oxidizer, liquid acid or
liquid base, depending on what reacts better with the sample at hand.
The optimal flux-to-sample ratio is found when all the sample is dissolved, and
almost saturates the flux solvent.
Summary of Contents for K1 PRIME
Page 1: ...Automatic fluxer 1...
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