Iron oxide pigment is widely used in many industries because of its wide chromatography, tasteless, non-toxic and low price. Ceramic industry is no exception. In recent years, with the development of ceramic industry, the amount of iron oxide pigment in ceramic industry is also increasing year by year. Our company has increased investment and research in its field year by year, and has achieved fruitful results in the application, characteristics and principle of ceramic iron oxide.

1.  Application:

Ceramic products are mainly divided into seven categories: Architectural ceramics, sanitary ceramics, garden glass ceramics, art ceramics, daily-use ceramics, industrial ceramics and special ceramics. Iron oxide pigments are widely used in these seven categories of ceramic products.

2. Characteristics and principles:

Iron oxide pigment has excellent coloring performance. In ceramics, the coloring of iron oxide is mainly used to prepare glaze water of various colors. Due to the different price of iron ions, the iron oxide itself is multi-color. When iron oxide is added to other glazes, the glaze color will be richer and brighter. In addition, in the manufacturing process of ceramics (glaze), different firing atmospheres are adopted, and the color of iron oxide is also different. Under the oxidizing flame atmosphere, the color of iron oxide changes from yellow to reddish brown, and then from grape red to brown. Under the reducing atmosphere, it shows blue to gray color changes, which are the result of the mutual transformation of the dynamic balance of Fe2 + and Fe3 + in the glaze layer.

1. Application of iron oxide as raw material of ceramic body: ceramic body is the basic material of ceramic.

Iron oxide, as a colorant of green body raw material, is mainly used in building ceramic medium wall and floor tile products. For example, the pigment preparation process of imitation granite unglazed porcelain brick is as follows:

Iron oxide pigment and a small amount of blank are mixed into color slurry in the ball mill, and then controlled by the quantitative pump to enter the mixer. In the mixer, a certain proportion of color slurry and base slurry are mixed into color slurry at high speed, and then the pigment and base slurry are sprayed into the drying tower according to a certain proportion to produce color powder.

The production process formula of imitation granite unglazed porcelain brick is:

Plasticity raw material 20-30%

British and other barren raw materials 20-40%

Feldspar flux raw material 20-30%

Special pigment additives 1-5% (such as iron oxide, chromium oxide, etc.)

Due to its excellent coloring function, iron oxide has become the main raw material for the preparation of colorant of imitation granite unglazed porcelain brick. For example, the green body chemical composition of yellow imitation granite porcelain brick is as follows:

SiO269%、Al2O318%、Fe2O3＋TiO23%

CaO＋MgO1. 5%、K2O＋Na2O4. 5%, loss on ignition 4%

In addition, iron oxide pigment is also added to some raw materials of purple sand pottery products to adjust the color of purple sand products.

2. Application of iron oxide in ceramic glaze: glaze is a continuous glassy layer attached to the ceramic surface.

In ordinary ceramics, the colorability of iron oxide is mainly used to prepare glaze water of various colors. The iron oxide itself presents different colors due to the different price of iron ions. For example, ferric oxide (Fe2O3) is red powder, ferrous oxide (FeO) and ferric oxide (Fe3O4) are black powder. Different iron oxides can be selected according to needs. In addition to the multicolor of iron oxide itself, when iron oxide is added to other glazes, it can make the glaze color richer and brighter. For example, iron oxide is added to boric acid glaze containing alkali metal to show the red color of wine; When iron oxide is added to semi matte and matte white glaze, it presents a series of tones from bright brown, yellowish gray and camel to dark brown; When iron oxide is used to make yellow glaze, it only needs to add a few percent of iron oxide to show a very thick yellow.