Ball clay is mostly composed of kaolinite, mica, and quartz. Ball clay has a high plasticity and shrinkage rate. It is used to make clay simpler to work with by increasing the flexibility of the clay body. China Clay is valued for its whiteness and purity, but it has little flexibility, making it difficult to work with.
Clay is a general term for any fine-grained sedimentary rock that is capable of being molded into balls or bricks when moistened. The most common clays are silt and sand, which are the main components of alluvial deposits; they can also be found in glacial deposits and certain volcanic rocks. Clays are used to make pottery because of their absorbent quality and their ability to take on different colors from pigment added during processing.
In geology, clay is defined as a non-metallic mineral that can be formed under conditions that preclude the formation of other minerals. Although many types of clay exist, they can generally be divided into two groups: colloidal and non-colloidal. Colloidal clays have particles that are less than 2 nanometers in diameter, while non-colloidal clays have particles that are larger than 2 nanometers. Both colloidal and non-colloidal clays can be used in ceramics.
Clays contain both aluminum and silicon atoms bonded together in layers called sheets. These layers can stack up to three deep, forming structures called phyllosilicates.
Ball clays are fine-grained, extremely plastic clays that are primarily employed in the production of ceramic whiteware and sanitaryware. They are valued for their fluidity, unfired strength, and pale color after firing. Ball clay is used to make bowls, tiles, vases, pots, and other objects that are used for cooking or serving food.
Clay is the main ingredient in many things we use every day. It can be found in paints, varnishes, and wallpapers as a filler material. In medicine, it is used in pottery and as a glaze for ceramics. You may have come into contact with clay before - perhaps while at school you made models out of it or used it to make toys. Clays are classified according to their source material, such as kaolin (which is mined from the earth) or scoria (which is waste material from a volcano). Clays can also be differentiated by their chemical composition, particle size, and firing behavior. The type of clay you use affects the final product - for example, if you use too much aluminum in your clay mixture, then when you fire it, some of the aluminum will burn off, but if you use too much iron, then when you fire it, the iron will remain in the clay and make it hard.
There are several types of clays, each with its own properties.
Ball clays are kaolinite-rich secondary clays that range in color from dark brown to black due to a high organic impurity concentration. It will turn white to a light cream color when it has been burned. It is made up of three primary minerals: kaolinite, mica, and quartz. It is a clay with a high plasticity and a higher concentration of tiny particles. This makes it useful as a filler for rubber products, such as tires. It can also be used as a pigment extender for paints and plastics.
The other major component is silicon dioxide (silica), which is the basis of glass. Some clays contain aluminum oxide or magnesium oxide as well. The type of mineral present determines what applications may work best with them. For example, pyrolusite is similar to ball clay but more yellow in color.
Mineral makeup of ball clay (source): silica, alumina, magnesia, iron oxides, calcium, potassium, sodium, titanium, zirconium, chromium, manganese, zinc, boron, phosphorus, sulfur, helium, oxygen, carbon dioxide, nitrogen.
There are several types of ball clay including: Norwegian ball clay, French green clay, German red clay, and English white clay. Each region has its own specialty clay that can be used for different purposes. For example, Norwegian ball clay is used for mold making while English white clay is used for sculpting because it doesn't get sticky when heated like other clays do.
They might have a broad range of plasticity, particle size, raw color, and drying qualities. In practice, though, most are quite similar. A typical ball clay powder is light grey (derived from lignite) or cream in hue and flames to a buff or cream color (with some soluble salt deposits on the fired surface). It has a relatively high silicon dioxide content (70% or more), low iron oxide content, and no real odor. Its specific gravity ranges from 3.5 to 4.5.
Clay particles are hydrophilic (water-loving) molecules that attract and bond together under water pressure to form strong but pliable objects. The key property that makes up for the hydrophilicity of ball clay is its high silica content. This means that it can be molded into different shapes and used as a substitute for other clays in ceramics projects.
When you mix ball clay with water, several things happen at once: water penetrates the clay's microstructure, swelling it slightly; then the clay's negative charges attract nearby water molecules until the mixture reaches the point where additional water molecules cannot absorb any more. From this point on, the only thing that can happen is that more water leaves than enters, which causes the clay body to dry out over time.
This reaction is what allows you to make objects out of ball clay. As soon as you add more water than ball clay, you have a paste that you can work with.