Which flux materials should be changed to lower the maturing temperature of the glaze?

Unit 3 Topic 6
Focus on Raw Materials

Whiting and / or feldspar could be increased or another flux material such as dolomite could be added.

Two of the existing materials provide flux oxides i.e. feldspar and whiting.
Increasing whiting would provide more calcium flux (CaO).

Increasing feldspar would not only increase the flux content (K2O, Na2O, CaO) but would also add more amphoteric (Al2O3) and glass-former (SiO2). Thus an increase in feldspar should be accompanied by a decrease in clay and perhaps silica so that the amphoteric and acid content is held at original levels.

Recipe Quantity
Flux
Amphoteric
Acid
Feldspar
40
provides---> K2O, Na2O, CaO Al2O3 SiO2
Whiting
30
provides---> CaO --------- -------
China Clay
20
provides---> ------ Al2O3 SiO2
Silica
10
provides---> ------ --------- SiO2
Dolomite
?
provides---> CaO, MgO --------- -------

Adding a new material such as dolomite would provide more CaO and bring a new flux MgO.
.

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