Na feldspat is a kind of common feldspar mineral, which is sodium aluminosilicate (NaAlSi3O8). It can soften the glaze surface and reduce the melting temperature of the glaze. In the ceramic industry, it is mainly used as ceramic body ingredients and ceramic glazes.
Sodium Feldspar used in Ceramic Glazes
In ceramic glazes, sodium oxide is generally introduced from albite feldspar, which has a better melting effect than potassium feldspar, can reduce the melting temperature and high-temperature viscosity of glaze, has a larger expansion coefficient than potassium feldspar, has a narrower firing range than potassium feldspar.
The effect of sodyum feldspat in the glaze is similar to that of potassium feldspar. Therefore, in the experiment on the influence of the albite single-factor experiment on the glaze effect of pink green glaze, the results are similar to those of the potassium feldspar single-factor experiment. The content is 5 ~ 11%. At this time, the gloss of the glaze increases, and the initial melting point of the glaze decreases. However, albite dissolves quartz, clay, and mullite at high temperatures the fastest. Therefore, when the amount of flote sodyum feldspat increases, the melting of quartz is accelerated, and the mechanical strength of the glaze is improved. At this time, the glossiness of the glaze continues to increase, and as the amount of Soda feldspar increases, when the amount of albite increases to between 11 and 17%, at this time The gloss of the glaze decreases, and when the amount of albite continues to increase, the bubbles become larger, so the gloss decreases. Therefore, according to the experiment, the glaze effect is the best when the amount of sodium feldspar is 11%.
If you want the glaze whiteness to be better, you can use potassium feldspar. After melting, potassium feldspar contains many small bubbles and becomes milky. The transparency of albite feldspar is better than that of potassium feldspar.
Albite feldspar is the main choice for antique glazes that require high color development. It is recommended to use two kinds of feldspar together. Generally, potassium feldspar: albite feldspar = 1:2~1:1, which can be adjusted according to the actual situation of the double alkali effect.