Tellurite And Fluorotellurite Glasses For Active And Passive

3. Glass batching and melting; MDO 70
In the first column of the input window (see fig. (3.1)) the required oxide and fluoride
components in the final glass were selected from an alphabetical drop down menu. A
different chemical had sometimes to be batched from the required chemical in the
final glass, for example due to decomposition during melting (e.g. Na2CO3 Na2O +
CO2↑ [1]). If applicable this different chemical was selected from a drop down menu
in the third column. The molar % of each component required in the final glass was
entered into the fifth column and finally the mass of the final glass required was
entered at the bottom of the window in grams. The ‘Calc from Mole%’ button was
then pressed and the weight % and weight in grams of each component were
calculated. A description of the glass could be entered and the complete table printed
off for reference when batching.
An example batch calculation will now be shown for the composition MOF001
shown in fig. (3.1). The calculation was for 10g of glass of composition 65TeO2-
10Na2O-25ZnF2 (mol. %). The ratio (by weight) of one mole Na2CO3 needed to
produce one mole of Na2O in the final glass is shown by equation (3.1), where RAMx
is the relative atomic mass of compound x:
[ RAM Na ] 2CO3
[ RAM ]
Na2O
105.
99
= = 1.
71
61.
98
(3.1)
Equation (3.2) shows the weight % of TeO2, where Wt.%x is the weight % of
compound x in the glass, and mol.%x is the molar % of compound x in the glass:
Wt.%
TeO2
=
( mol.%
TeO2
× RAM
TeO2
mol.%
) + ( mol.%
TeO2
Na2O
× RAM
× RAM
TeO2
Na2O
) + ( mol.%
ZnF2
× RAM
ZnF2
× 100
)