FELDSPAR IN CERAMICS
As a flux for vitrification: In ceramics, the alkalis in feldspar (calcium oxide, potassium oxide, and sodium oxide) act as a flux. In the ceramic industry, the flux is defined as that portion of the body which develops glass phase. Fluxes melt at an early stage in the firing process, forming a glassy matrix that bonds the other components of the system together. This improves the strength, toughness, and durability of the ceramic body. The amount of flux in a ceramic body should be only in such a proportion as to develop the desired amount of vitrification.
If excess of flux is added, the fired body becomes very glassy and consequently, brittle.A very special property of feldspar, which makes it a highly favored flux in the ceramic industry, is that it does not have a strict melting point. In contrast, it melts gradually over a range of temperatures. This greatly facilitates the melting of quartz and clay and, through appropriate mixing, allows modulations of this important step of ceramic making.
In glaze preparation: Feldspar is also used in the preparation of glazes as a source of alkalis and alumina. The fine powder of feldspar is mixed with silica powder and thin slurry is made. The fired goods are dipped into the slurry and fired again. This imparts glaze to the surface. Feldspar assists the enamel composition, assuring the absence of defects and the neatness of the end product.
Anand Talc is an experienced supplier of ceramic grade feldspar. Our feldspar can be used in various kinds of ceramic products from pottery to tiles to sanitary ware. Our feldspar is low in iron oxide. Moreover, we keep tight watch on our whiteness, and measure every color related aspect with sophisticated spectrophotometers to give to our customers uncompromised quality of feldspar, for use in ceramics.