Ceramic Iron Oxide Pigments

Iron oxide pigments are commonly used in ceramic glazes and clay bodies to create a wide range of colors. They are tasteless, non-toxic and inexpensive.

Red iron oxide is the most common form of iron oxide used in ceramics. Other forms include black and yellow.

Colors

Colorants can be added to glazes or clays to create a multitude of hues. They can be derived from many different sources including cobalt, chrome, copper and red iron oxides. The coloring agent is incorporated into the basic glaze or clay and then fired at various temperatures and in various atmospheres to produce the desired color.

Ceramic iron oxide pigments are primarily used in glaze applications to produce a range of colorful effects. They are also useful in coatings and in the production of glass, plastic, rubber and textiles.

These pigments come in a variety of colors, including yellow, black and red. The red pigments are derived from the iron oxide mineral hematite. They are often tinted with other minerals to make them more intense or to change their shade.

Some red iron oxides are hydrated, meaning that they have been treated to become more stable during use in ceramic compositions. This process allows the color to be more durable when exposed to higher heats during the manufacturing process.

In addition to being more resistant to heat, they can also be applied more quickly than other pigments of the same size and intensity. This makes them ideal for use in raku-fired glazes and a wide variety of other applications.

The most common colorants in the world are red, yellow and black. They are used as body, glaze and coating pigments in the ceramic industry.

Hematite is a natural red pigment that can be found all over the world. It has been used in art for tens of thousands of years, as evidenced by the 32,000-year-old cave paintings at Lascaux, France.

It is a common red iron oxide that is used in industrial paints, coatings and other applications. It is a strong pigment that can be easily dispersed in water-based systems and VOC-free coatings, and it is available in various particle sizes.

Depending on the source of the iron oxide, cooking conditions and treatment after coloration, different shades of red-orange are produced. Some of these are ceramic iron oxide pigments ochres, sierras and umbers, while others are more tan or brown.

Purity

Ceramic iron oxide pigments are produced in a number of ways. They are produced by mining and processing natural iron oxides or by combining chemicals with the raw materials used to mine or process natural ore into finished pigments to be sold or painted.

The most common methods of producing iron oxides involve solution techniques, in which a chemically prepared liquid is dissolved in water to form the compound with a desired color and physical property. A variety of compounds can be synthesized by this method, and some are more stable than others in certain applications. The primary oxides obtainable by this process are ferric oxide hydrates, magnetite and ferrite tans; the latter is a nonmagnetic iron oxide derived from the reaction of a hydrated iron oxide with magnesium or zinc oxide.

Other methods of obtaining synthetic iron oxides include precipitation, which involves the application of a small amount of water to a powdered material to generate an oxide. This process, which is relatively easy and inexpensive to perform, can produce iron oxides in a wide range of colors.

Pigments made from this method are generally lightfast and opaque, and can be used in a variety of applications such as paints, varnishes, plastics, rubber and other insulating materials. They can also be blended with other pigments to produce a wider range of colors.

In addition to being lightfast and opaque, these pigments are highly durable in a wide variety of applications. For example, they are frequently used in roofing granules and as a colorant for many types of cement mortar. They are also used in various types of color plastics, and in various water-based and oil-based paints.

These pigments can also be blended with organic dyes to give them a broad range of colors. This can be useful for decorative or industrial purposes, and is particularly common in the manufacturing of glass and plastic.

Micaceous iron oxide is another natural iron oxide that has been used for a long time as a pigment. It is a flaky hematite whose platelike nature provides exceptional weathering resistance. It can be formulated into coatings for industrial tanks, refineries, chemical plants and drilling rigs. It is often employed as a painting medium for buildings, including the Eiffel Tower in Paris.

Dispersibility

Iron oxide pigments are used in a wide range of applications, from dyes and paint to food packaging, cosmetics and pharmaceuticals. They have many advantages, including high stability, nontoxicity, ease of handling, and ready availability. Natural iron oxides, primarily from hematite and limonite, have long been used in painting, but chemical methods developed in the 20th century have made synthetic iron oxides the dominant colorants.

Ceramic iron oxide pigments are manufactured in a number of ways, but the most common is to grind and then re-grind the powder into a uniform, thin film, which is then fired. The resulting film has a high density, and it is very durable.

Because of this durability, the pigment is used in a variety of products, including glass, metals and concrete. It can also be used in ceramics to make decorative items and figurines.

When the pigments are formulated into glazes, they tend to disperse well in water. However, when they are added to a glaze in unscreened form, there may be specks that require screening to remove. This is a problem with some brands of iron oxide, so it is best to check with your manufacturer before adding this pigment to your glazes or other ceramic products.

To make these specks disappear, you can use a fine screen or ball mill to reduce the size of the clumps. You can also add a small amount of talc to the pigments before mixing them into your glaze.

The talc may help break up the particles, but it will not completely dissolve them. If you do not want to use talc in your pigments, you can still mix the iron oxide with a small amount of water and then use a screen or ball mill to break up the lumps.

Iron oxide pigments are a small but important part of the pigment industry, and the demand for them will likely continue to increase. But they are prone to fluctuations in demand, and the decline of certain deposits may have an adverse effect on supply. Nevertheless, their low cost and chemical and physical stability should keep them in use for some time to come.

Heat Resistance

Iron oxide is a widely used pigment in paints and coatings. Its advantages include high hiding power, tinting strength, color fastness, bleed and chemical resistance, ease of dispersion in all vehicles, low price, and good infrared reflectance and ultraviolet absorption. It can also be adapted to different types of vehicle and substrates, and is resistant to weathering.

Ceramic iron oxide pigments are available in a wide range of colors and can be used in many different applications. They are suitable ceramic iron oxide pigments for use in architectural ceramics, sanitary ceramics, garden glass, fine art ceramics, daily ceramics, industrial ceramics and special ceramics.

Natural and synthetic iron oxides are produced from a variety of sources. Some of these sources are naturally occurring deposits that contain hematite, magnetite, and ferrite. Others are mined from chemical raw materials.

In the United States, natural iron oxides account for about half of domestic shipments and have dominated value over synthetics since 1964. The balance is synthetic oxides.

Despite this dominance of synthetic oxides, natural iron oxides remain important to the industry because they are used as pigments. They are produced from both lump ore, which is mined in ore pits, and from ores of metals that are oxidized with hydrochloric acid.

As in other industries, iron oxide producers have had to take steps to limit air and water pollution. This has meant implementing equipment to keep emissions within acceptable levels and more extensive facilities to meet environmental standards for wet-process production of synthetic oxides, which requires handling acid solutions containing solid fine particles.

This has made synthetic oxide manufacturers much more cautious in minimizing emissions from their operations, and has led to the development of environmentally friendly technology. For example, some waste sulfate and chloride from titanium pigment and steel production can be treated by using them in wastewater treatment systems.

Micaceous iron oxide, another natural form of the material, can be used as a pigment in paints and coatings. It imparts unique properties to a surface because its flaky particles align in such a way as to resist penetration by moisture and gases that could otherwise lead to rusting.