Kaolin clay, also known as China clay, is made up mainly of the mineral kaolinite, silicate, and small amounts of additional minerals. The said minerals include quartz, muscovite, iron sulfides, micas, and titanium dioxide-based impurities like an anatase mineral.
Anatase itself is known as a mineral that forms translucent crystals. However, when it is found within kaolin clay, it will instead give the clay a brownish hue. Read on to know more about anatase as both standalone and composite minerals.
What is Anatase Mineral?
Anatase is one of the three naturally occurring minerals that compose titanium dioxide (TiO2), in which the other two are rutile and brookite. At significantly higher temperatures, anatase will naturally revert to the form of rutile, making it the rarest mineral of the three.
Anatase is also known for being a distinctive and aesthetically-pleasing type of TiO2. This mineral is generally found in hard, dazzling crystals with tetragonal shapes and a variety of colors in veins.
Detritus placer deposits, igneous, and sedimentary rocks are where an anatase mineral can be mined. Many sections of the Alps are known for being the regions where anatase occurs in vein deposits. In addition to this, Bahia and Minas Gerais in Brazil are also widely known for the placer deposits the anatase can be extracted.
Properties of Anatase
Below are the properties of the rarest mineral that made up kaolin clay:
1. Physical Properties
In terms of physical properties, anatase commonly appears in translucent crystals, with black as the most common one. However, it can also be reddish to somewhat yellowish-brown, white, dark blue, or even colorless.
The anatase mineral in gray, green, and red are generally uncommon. This mineral, on the other hand, can sometimes have splotchy darker, and brighter spots. When occurred in light hues, it will be transparent.
Even if it’s translucent, it can give brownish hues to kaolin clay due to its higher-level content of iron. Therefore, this impurity mineral must be removed to improve the brightness of the clay by performing froth floatation.
2. Optical Properties
As for the optical properties, anatase has refractive indices that are varied depending on the wavelength and temperature of the place where the mineral is extracted. Some anatase crystals in dark colors with small-sized 2V tend to have the feature of the biaxial optic.
When exposed to ultraviolet light, anatase will absorb it heavily. It’s also active at a photochemical level and often causes admixed surfaces to deteriorate. Early pigments of anatase are prone to chalk and discolor when exposed to UV light.
3. Chemical Properties
While considered one of the rarest minerals that made up the chemical formula of kaolin, anatase instead has perfect hardness and cleavage of approximately 6. At a chemical level, anatase is inert, highly soluble in water and organic solvent.
Those chemical properties make anatase minerals ideal for jewelry makings, such as earrings, brooches, and pendants. The chemical content that makes up anatase makes its birefringence exceed those of diamonds. This typically can be seen in anatase with transparent hues.
The Uses of Anatase Mineral
Anatase is a mineral widely utilized in a variety of industries, including papermaking, coatings, ink, rubber, plastics, chemical, pharmaceutical, and so on. The following are some of the standard applications for anatase:
1. White Pigments Making
Along with a rutile mineral, anatase is the most frequent type of titanium dioxide used to make white pigments. This pigment itself is one of the primary ingredients for the production of paints, paper, ink, toothpaste, and even skim milk.
This sort of consumption is estimated to be around 4 million tons per year. Industrial anatase, however, is made by chemical manufacturers, where titanium dioxide is extracted from rutile. It’s the ideal alternative for natural anatase which known for being extremely rare.
2. Skin Care and Cosmetics Products
As titanium dioxide, anatase often becomes one of the primary formulas in making pigment and a thickener for beauty products. As a beauty cream, anatase is utilized for its UV light absorbing abilities and transparency.
Skincare products, such as sunscreen, are specifically employed anatase in their chemical formula because it’s believed to have properties that can provide protection for the skin against direct UV lights.
3. Paper Making
Another benefit of the anatase mineral is that it can be utilized in the making of white paper. The properties of brightening and fluorescence and boosting the whiteness of the sheet are the primary reason this mineral is used in the papermaking industry.
A coating thickness of fewer than a hundred millimeters is necessary for the printing industry, which is why very thin anatase pigments are utilized. This industry also makes use of other ingredients, such as kaolin clay which is composed of anatase, talk, and chalk.
Anatase is a mineral made up of titanium dioxide, which is commonly used in white pigments in a wide variety of food products, including white sauces, skim milk, candy, and coffee creamer. E171 is the food additive that is used to add this substance. Nanoparticles make up a small amount of these insoluble anatase particles.
5. Environmental Benefits
Apart from being useful in commercial uses, anatase has also proven beneficial for a wide range of environmentally eco-friendly applications, thanks to its properties. When employed as the ingredient of paint and is applied on the outside, the light-reflecting qualities of this mineral can result in significant energy savings since it lessens the demand for air conditioning.
As one of the photocatalyst minerals, anatase can be used in tiles, cement, paints, and glass to help decompose pollutants. It may also be utilized as a DeNOx catalyst in vehicles’ exhaust gas systems; thus, reducing their impact on the environment.
Anatase is one of the three minerals that make up titanium dioxide. The mineral itself is present in sedimentary soils, such as kaolin. However, the kaolin’s anatase content is usually removed to purify the clay from the impurities.
For a mineral that is considered rare and obscure to the general population, it’s astonishing knowing how many daily goods anatase can be found. However, since naturally occurring anatase minerals are hard to come by, the use of synthetic anatase for commercial applications is preferable to accommodate the industrial needs of this mineral.