Mica-WHAT IS CAOLIN?

WHAT IS CAOLIN?

It is a light-colored earth very rich in kaolinite. Due to its color it is also called white clay, so talking about kaolin or white clay in this case would be the same. The whiter its color, the greater its purity, since it would be free of materials such as oxides or elements of plant origin.

And what is kaolinite?

Kaolinite or kaolinite is a mineral, it belongs to the class of silicates (subclass of phyllosilicates and kaolinite-serpentine group, for those who are interested in something more technical).

It occurs naturally in loose or compact earthy compounds, forming sheets.

It is a common component to other types of clay, such as " ball clay ."

Where does this appreciated white clay come from:

The name of kaolin clay comes from the French kaolin, in turn from the Chinese kao-ling shan 高岭山, this is the name of a mountain (shan 山 means mountain) in the province of Jianxi, towards the east of China, a This area is also known as Porcelain Land. Hence it also receives the English name "China clay". Although its name comes from this first location, there are obviously deposits of this white stone in many other parts of the world (eg in Africa it is called Kalaba).

It is one of the most appreciated materials used in ceramics , luckily it is relatively abundant in the Earth's crust. You can imagine its age..., depending on the sources that talk about this material and its sites, various ages are considered, but the vast majority of them are no less than 100 million years old.

Chemical composition of kaolin:

It is an aluminum silicate. Its formula would be:

• Aluminum oxide (Al2O3). About 40%
• Silicon oxide (SiO2). About 45%
• Water (H2O). THE remaining 15%.

PROPERTIES OF KAOLIN

• It is whitish , hence it is known as white clay. Now, it may not be pure and the other elements present can, logically, give it color; Plus it's matte .
• It has low hardness , grade 2 on the Mohs scale. If this doesn't tell you much, to give you an idea, it would be similar to plaster, you could scratch it with your fingernail. It is closer to talc in hardness than many other clays.
• It is odorless .
• Very absorbent .
• Its pH is NOT neutral , as you read in many places, but rather a little acidic. What happens is that its pH (between 4 and 6) is similar to that of human skin (between 4.7 and 5.75), which is also acidic, hence the confusion. The neutral pH is 7.
• It may have a creamy feel , this and other characteristics of kaolin will logically depend on the proportion of kaolinite it contains, the higher the percentage of solids, the lower the viscosity.
• The economic benefit it brings, for example in Spain, in terms of its use in ceramics, even when it is used in smaller quantities than other clays, represents more than two thirds of the total value of the clays that are sold. Its multiple properties in terms of benefits for humans give it many uses that we will explain to you later.

WHAT IS CAOLIN USED FOR?

It is a material whose properties make it suitable for a lot of different, very numerous and varied applications.

USES OF CAOLIN IN CERAMICS:

The application that we highlight here is its use as a material to make porcelain and with it all the types of pieces called as such, with functions such as decorative figures , or that may also have some use, such as vases, cups and plates for all types of tableware , etc. As well as to manufacture toilets.

This mineral, when it is part of ceramic materials, which are the result once this earth is cooked, gives them plasticity. It also provides great resistance to cooking and, after cooking, to the final result. Let's not forget that one of the keys to porcelain is that it is a ceramic that is fired at high temperatures . On the other hand, it provides control over the shrinkage or contraction of the pieces.

Because of this relationship with heat, the final ceramic objects are refractory .

Furthermore, they do not have any water absorption.

Once the minerals have been incorporated and the entire process has been carried out, the final porcelain is obtained, known for its white, translucent appearance and soft to the touch. Kaolinite is essential in this process due to its physical properties, such as its whiteness, strength, and ability to retain intricate shapes.

Now, outside the field at hand, it has an infinite number of different uses, let's see them.

INDUSTRIAL APPLICATIONS OF KAOLIN:

As refractory material:

Withstands high temperatures, even for long periods of time. It does not expand or contract too much in what is called "thermal shock." It is part of the ceramics that are used as a thermal insulator, since it prevents the spread of heat.

As electrical insulator:

Ideal as a component of insulating ceramic elements (mostly porcelain) in many installations. In addition to avoiding any conduction of electricity, it is what is called "chemically inert", that is, it does not react with it.

In the paper industry:

Included in its composition, it improves the impression on it and gives softness, whiteness and shine to the leaves.

The low viscosity and brightness that it provides to the paper also makes it very effective in coating sheets that are intended for photographic printing and in which good luminosity is needed in color printing.

In the manufacture of ink

To improve your retention. It has another advantage, that being of very low hardness it is hardly abrasive, so when used in inks used in the press, the printing plates are hardly affected or damaged over time. The kaoli in the ink helps it stay on the surface it has been printed on.

Also,In painting:

Acting as what is called a pigment extender, what it does is modify the brightness, texture and properties of the final product, adapting them to the manufacturer's needs and without color modification problems. Widely used in exterior base paints, with an oil-based composition.

It also makes it easier to remove stains when washing. Prevents polishes from penetrating the interior of the objects to be treated.

Rubber industry:

It gives the final product rigidity and resistance. This clay is ideal for pigmentation, and is not very expensive compared to other dyes. More than 700,000 tons of this white mineral are used each year in this sector.

Plastic manufacturing:

It is mainly in PVC where it is used the most. Provides smoother surfaces, and prevents excessive shrinkage that causes parts to crack. It also gives them greater resistance.

In the construction:

It is a fundamental material for the manufacture of sanitary ware, due to the low porosity it provides. It is used in other ceramic materials for construction, such as tiles, tiles, both as part of its structure and in its coating to give it greater resistance to the elements.

What is it for in agriculture:

By creating a protective film when applied to plants, it prevents water loss in times of low humidity and insulates from heat, preventing excessive evapotranspiration, minimizing the amount of radiation that reaches the plants.

For example, it is used to reduce the adverse effects of heat stress in olive trees, acting as an effective protector against high temperatures. 

As a natural insecticide:

Helps control pests, an alternative to sulfating crops. It is frequently used in olive groves.

In the construction:

It is a fundamental material for the manufacture of sanitary ware, due to the low porosity it provides. It is used in other ceramic materials for construction, such as tiles, tiles, both as part of its structure and in its coating to give it greater resistance to the elements.

Here you have an interesting and complete video about the manufacture and uses of this "multipurpose" mineral.

WHITE CLAY IN COSMETICS:

Kaolin has been used for aesthetic reasons since the first civilizations, such as ancient Egypt. We explain what benefits it has on the skin and what other uses it has for aesthetics and hygiene in general.

As a facial mask , this clay helps regulate the oil level of the skin, so, although it is suitable for all skin types, it is recommended for oilier skin types, due to its sebum-regulating properties. Due to this, it can also help in the treatment of acne, also thanks to its antiseptic qualities.

It is a clay that also causes exfoliation , eliminating dead cells, although the particles, being fine, are not too abrasive for the skin, which is why they are indicated for sensitive skin for which other clays would be too aggressive. It is recommended for young skin that is thin, taking into account that its tendency to be oily is more common at these ages.

It is nutritious for the skin due to its mineral components.

It is even used to make shampoo , mixing it with baking soda and Maizena (cornstarch flour). It is a dry shampoo that is applied to the hair with a brush and, after allowing about ten minutes to pass, it is removed by brushing the hair.

As a natural deodorant , due to its antibacterial characteristics, it provides dryness against sweat and prevents odor. It is also mixed with Cornstarch and in this case some fatty substance is added (such as some oil or butter) and some other substance that gives aroma, such as an essential oil.

It has been given properties to reduce skin spots, wrinkles, and to help with psoriasis and stretch marks.

It is used as an ingredient to make natural toothpaste , as it is alkaline, antibacterial, anti-inflammatory, due to this there are many recipes to make homemade toothpaste with this white clay. They generally include, in addition to this ingredient, baking soda, coconut oil and a little bit of mint essential oil, to give a fresh flavor. Sometimes aloe vera and/or unrefined sea salt are added. If you are interested, here you have several options.

MEDICAL USES:

Many beneficial properties are attributed to it. Go ahead and say that any of them should be taken with caution and always under the advice of registered professionals.

• In the pharmacological industry it is used as an excipient in medicines.
• As a bactericide.
• As it is molecularly arranged, it has a great absorption power, as we mentioned, which is why it is also used to treat digestive system problems such as colitis. Laboratories include kaolin in their formulations, not only as an excipient, but as an active ingredient, mixed with pectin (vegetable fiber that helps eliminate toxins from the body) or methylcellulose.
• Healing and anti-inflammatory properties are attributed to it.
• There are countless treatments in natural medicine that include it.

CALABACHOP: EDIBLE KAOLIN?

Yes. This mineral is eaten . There is a widespread custom especially in Africa, in Equatorial Guinea where it is known as calabachop ; It is also eaten in Cameroon, Senegal and Gabon, where it is called Kalaba. This tradition is also found in areas of the US where there is an African-American population, as well as in Haiti.

This edible white soil or other earthy material is known as geophagy , and has been a custom or instinct throughout the evolutionary history of humans and their ancestors. This can be observed in the behavior of some young children.

Eating clay in some cultures is more common in the female population and during pregnancy. This is done because it is attributed beneficial properties for the digestive system and it is stated that it eliminates the nausea that occurs during pregnancy, supposedly protecting the stomach against pathogens, parasites and toxic substances. This is why it is used together with pectin (a plant fiber that helps eliminate toxins and waste) for gastrointestinal problems.

Thus, calabachop or edible kaolin, in various forms, however, you must always check the scientific evidence about the medicinal benefits of this land and consult with a doctor; On the other hand, it has been published that it could make it difficult for iron to be absorbed, so, if so, it would cause anemia.

What does calabachop taste like?

Anyone who has tried these materials will say that they are grounding.

How do you eat calabachop?

Although it is usually kept in stones, as it is a very soft material, it can be bitten and chewed directly. Although there are those who add it to food, in crushed form, in a teaspoon.

WHITE CLAY FOR RELIGIOUS PURPOSES

This may not be so well known: But kaolin is also used in religion. Yes, in Afro-Cuban practice. In Yoruba culture it is known as Efun. The Yoruba people are originally from West Africa, elements of their culture have reached other parts of the world.

You can see an interesting video here, in relation to these latest uses that we have told you about this clay, about the preparation of the so-called "bread of the blessed land."

I BUY KAOLIN

You won't have any difficulty finding where to buy it. Now, it will depend on the use you want to give it, and the quantity you need, since that need will range from small quantities to test a cream, something more for artisanal porcelain work, more if it is industrial, and even more if you are a constructor (we don't believe..., but if that were the case, quiminet.com has a list of exporters).

If you are going to look for it as edible you can find it as kalaba, white clay, or marmorkreide on Etsy . We leave you a link below.

You can buy kaolin for cosmetics , for masks, soaps, etc. at Foundin Bio , also on Etsy.

For use in ceramics, and in a handmade way, of course, you can find it in online stores such as Marphil , in Naturclay (more focused on construction, they sell bags of 20kg and up).

It will depend on the amount you need and the purity required for your work.

Prices:

There is a lot of supply of this white clay and many online sales sites where you can find it, adding that every time you look there are good offers on the Internet for one reason: Kaolin is in great demand in many different sectors (some with great competition such as cosmetics), which will benefit you when it comes to easily finding quality products at a good price, something that will not happen with other already very specific materials. To give you an idea, buying a kilo separately for pottery, prices can range between €1.80 and €4, depending on the quality, for example, an already treated clay of great whiteness such as Molochite, is more expensive.

Advice:

For ceramic work that does not require the quality necessary for cosmetics, DO NOT pay more than €5 for a medium quality and in the 1 Kg size.