Bentonite clay has several applications and uses in ceramic , pottery and glazing .1-3% bentonite can significantly improve glaze suspension. In addition, it will harden the dried layer. Coarse varieties may carry some enamel staining. If the glaze already contains more than 15% clay (kaolin, spherical clay), you will not need more than 1% bentonite. Colloidal bentonite, which is typically thinner than clay balls, can have enormous surface area and an active electrolyte that provides extremely high plasticity. In fact, without much effect on color when burned, bentonite can generate the drying power of myrtle. Based on ultrapure white clay, ceramic bentonite is preferred as a suspending agent in porcelain glazes and enamels, as well as a binder and plasticizer in white electric porcelain tiles, floors and coverings. Bentonite has been used in the ceramic industry for many years due to its method of performance in terms of plasticity and workability. However, there are some alternative methods that can facilitate their replacement, as they show some undesirable side effects when introduced into formulations. 
The use of bentonite clays was known in Roman times, where it exhibited a "soapy" behavior, but also shows high plasticity and colloidal dispersion capacity. It is an important agent in the ceramic industry, fabric cleaning and as a degreasing agent. These clays tend to expand when in contact with water, increasing their volume and generating thixotropic gels when added to water in small amounts. It is this last property that makes it so interesting for ceramics in combination with drilling muds, scrubbers, adsorbents and binders. Bentonite is commonly used in ceramic formulations at very low addition rates to modify ductility. Due to its interaction with water, captured in the leaves that form the bentonite structure, it allows the flow of ceramic pastes to be controlled. On some high-performance ceramic supports, the use of products that can severely affect drying cycles, such as bentonite, can become a nightmare. This is the main reason to replace bentonite with other additives, to achieve equivalent performance in terms of plasticity, rheology and final appearance. Bentonite is a fine-particle clay often used as a suspension agent in glass, ceramics and glaze. Bentonite has colloidal properties, which means that the particles are so small and light that they disperse in water and remain suspended rather than settling. 
Clays such as kaolin and ball clay are also suspending agents and are commonly found in decorating recipes. Without suspending agents, the enamel particles will sink and settle, forming a solid, immiscible layer at the bottom of the tray. This is called hard panning. Most bottles need at least 10% clay to remain suspended, mix easily and prevent solidification. If the glaze does not contain enough clay, bentonite can be added instead. Only 1% bentonite has approximately the equivalent suspension strength as 5% kaolin or spherical clay. So if the glaze contains 0-5% clay, you will probably need 2% bentonite to keep it suspended. If the glaze contains 5% clay or more and you are having trouble staying suspended, 1% bentonite is probably all you need to stay suspended. Bentonite also increases the hardness of the glaze after it dries. If your glaze is really dusty after it dries, which is often caused by a lack of clay, adding bentonite will help strengthen and hold the glaze. 
bentonite uses
Bentonite is a clay mineral with various applications and uses that has incredibly small size particles. This, along with the surface-active chemistry of the particles (which makes them retain water), makes them the most common plastic and impermeable clay material used in ceramics. Their contribution to the working properties of glass and clay pastes is balanced by the undesirable properties they also impart. Therefore, anyone who uses this substance should have his eyes open to get acquainted with its advantages and disadvantages. There is so much variation in the chemistry of bentonite, it is impossible to determine an average (bentonite is not used in ceramics due to its chemistry). Therefore, any general chemical analysis is merely an attempt to represent the quantities you might find in a common variety. Due to its high iron content, bentonite is considered a tarnishing material, and thus there is a trade-off between the valuable working properties it imparts and the need for pure whiteness or color that prevents it. 
Fine particle size: colloidal bentonite (the particles are so small that the effect of water molecules is enough to keep them in suspension). It is usually 10 times finer than plastic clay. Its surface area can be about 1000 square meters per gram (50 times the area of kaolin, 5000 times the area of silica flour). Plasticity: Due to its electrically energetic behavior and fine particle size, bentonite exhibits extremely high plasticity (and concomitant high shrinkage). In pottery and porcelain objects, additives of no more than 2% can result in marked improvements in workability and drying strength without significant effect on burnt color. The use of up to 5% is common, especially when the high plasticity of the burnt white body is required. However, the need for additives higher than this may indicate that there is no other clean or suitable clay in the recipe. 
Also, large amounts of bentonite significantly reduce the drying rate. It is practical in some applications to use bentonite as the sole plasticizer in the mixture (in higher percentages). The plasticity-producing effects of bentonite depend on the shapes, sizes, surfaces, and electrical analyzes of the particles with which it interacts. Equal additions of bentonite to two different host bodies can have substantially different effects on elastomers. Drying performance: Bentonite makes more plastic bodies and dries more, but this comes at a cost, it shrinks more during drying and therefore has more potential to crack. Bentonite is very plastic and test samples cannot be prepared (e.g., for drying, strength assessment, shrinkage). However, it is possible to extrude and form a mixture of 20-30% virgin material with calcined material (test samples will still be reduced to a very small size). Permeability: Most bentonites are impermeable to water. To demonstrate this, fill a tall glass cylinder almost to the top with bentonite, then carefully pour water on top. The water will only penetrate the mud a few millimeters and no matter how long you leave it in, it won't penetrate more than that. This happens because the powder swells when water penetrates and adjacent particles 'capture' the water between them. 
The water thus becomes a glue that holds the dough together and prevents further entry or passage. This phenomenon explains why glass materials and supports with a high content of bentonite dry out more slowly. For example, if you pour a slush mud on a gypsum surface, the water will often drain in seconds. However, a bentonite slurry may require days or weeks to extract the water evenly. Swelling: Most bentonite swells (up to 15 times) when added to water. This property is valuable in thickening liquids and slurries and is another factor that contributes to the preservation of suspensions. Bentonite is used in large quantities in the oil and gas extraction industries to suspend high specific gravity slurries which are used as a medium for flotation of cut rock pieces by drill bit. Suspension: Bentonite is used to keep particles suspended in all types of industrial and consumer products, and in ceramic glass. The mechanism is charge attraction, that is, opposite electrolytic charges develop on the surfaces and edges of the dispersed particles . 
bentonite ceramic
Bentonite 325 mesh is a standard additive for both glazes and ceramic. This is a fine powder of a tan gray color. Typical for ceramic use, this is sodium bentonite. Bentonite is a clay made up of very small particles, which makes this material very plastic. The fine bentonite particles remain in suspension in water, causing them to act as a suspending agent in the glass. Bentonite has been used in ceramics for many years due to its performance in terms of ductility and workability. However, there are some alternative methods that can facilitate their replacement, as they show some undesirable side effects when introduced into formulations. These clays tend to expand upon contact with water, increasing their volume and generating thixotropic gels when added to water in small amounts. This last property is what makes it so interesting for ceramics along with drilling, purifying, absorbing and bonding clays Bentonite can also be used as a paint thickener in small amounts, and can be a great way to thicken enamel if you don't want to use an organic compound. 
Adding bentonite to a body of clay in small amounts (about 2%) will add strength to dry, green clay as it binds the clay together firmly. In addition, bentonite can increase the elasticity of the clay body, but this addition can also increase the shrinkage of the clay body. Bentonite is commonly used in ceramic formulations with very small addition ratios to modify ductility. Due to their interaction with water, capturing it in the plates that make up the bentonite structure, they allow the rheology of ceramic plaster to be controlled.Bentonite can also slow down the rate of drying. However, large amounts of bentonite can lead to increased cracking during drying due to small particle size, so be sure to test the percentage you add to a dedicated clay body.
bentonite glaze
Bentonite acts like an additive to glaze. Most potteries need at least 10% clay to remain suspended, mix easily and prevent solidification. If the glaze does not contain enough clay, bentonite can be added instead. Only 1% bentonite has approximately the equivalent suspension strength as 5% kaolin or spherical clay. If the glaze contains 0-5% clay, you will probably need 2% bentonite to keep it suspended. If the glaze contains 5% clay or more and you are having trouble staying suspended, 1% bentonite is probably all you need to stay suspended. Bentonite also increases the hardness of the glaze after it dries. If your glaze is really dusty after it dries, which is often caused by a lack of clay, adding bentonite will help strengthen and hold the glaze. Bentonite can greatly improve the suspension of enamel by gel. In addition, it will harden the dried layer. Coarse varieties may carry some enamel staining. If the glaze already contains more than 15% clay (kaolin, spherical clay), you will not need more than 1% bentonite. water and wait for it to fall. You only want enough water to completely cover the bentonite. 
Bentonite is the most common plastic used in ceramics. Bentonite is used to add plasticity to clay objects and to help suspend glaze components. It should be mixed with warm water before adding to clay or glaze, or mixed well with other dry ingredients. If you're adding it to a wet frosting, try to mix it in right away. That's because when bentonite particles are partially wet, they attract and stick together, just like the clay we use to make pots. All clay particles generally have an opposite charge on the edges and faces that attract them and hold them together like a magnet in the presence of water. This attraction is what gives clay its plasticity so that we can mold and shape it. But if there is enough water between the clay particles, the attractive charge weakens and it no longer sticks together; Flowing freely. But, if you add bentonite to ordinary water and don't touch it, just let it soak in, all the little clay particles will be completely submerged, and the water will surround them on all sides. Once completely wet, the attractive charge weakens and the risk of bentonite particles clumping together and dispersing and floating freely around the bucket disappears. This process is similar to the removal of a dry clay body. If you add dry clay cuttings to water and let them sit, the clay will absorb the water and all the particles will break free from each other. This creates a smooth layer that can be blended in a smooth glide. But if you add a small amount of water to a batch of wet or dry scraps and then mix them together, the clay will stick together and become clumpy. The key is for the completely dry clay to come into contact with the water and stay put so it can erupt. 
bentonite ceramic glaze uses
Bentonite clay has wide uses and applications in ceramics and glazing industries. Due to its high iron content, bentonite is considered a tarnishing material, and thus there is a trade-off between the valuable working properties it imparts and the need for pure whiteness or color that prevents it. Due to its electrically energetic behavior and fine particle size, bentonite exhibits extremely high plasticity (and concomitant high shrinkage). In pottery and porcelain objects, additives of no more than 2% can result in marked improvements in workability and drying strength without significant effect on burnt color. The use of up to 5% is common, especially when the high plasticity of the burnt white body is required. Large amounts of bentonite will greatly reduce the drying rate. It is practical in some applications to use bentonite as the sole plasticizer in the mixture (eg 5-7.5% with Redart to make clay). The plasticity production effects of bentonite depend on the shapes, sizes, surfaces, and electrical analyzes of the particles with which it interacts, and equal additions of bentonite to two different host bodies can have very different effects on plasticity. Below is the list of material needed to make glaze. Each glaze is made from the following three materials: Silica: Produces glass. Examples: quartz, flint, pure silica and bentonite Alumina: The glaze is hardened so that the clay does not slide off. Examples: Clay (kaolin, ball clay or igneous clay), alumina hydrate Flux - causes the glaze to melt at a temperature low enough to be used in pottery. Examples: feldspar, albedo In addition, the glaze may include one or more additives: Opaque materials: To make the enamel opaque instead of transparent. Examples: tin oxide, zirconium or zircopax, titanium, zinc Brackets: To keep the coating in suspension rather than stable. Examples: bentonite Colorants: To provide different colors. Examples: cobalt oxide, copper oxide To provide silica in the glaze, we need a material that contains: SiO2 = silicon dioxide, comes from flint, quartz and pure silica and bentonite.