What is Kaolin?
Kaolin is classified as a fine, white clay composed of the mineral kaolinite. The low abrasion of the material coupled with the ability to engineer and purify it through specific processes are key reasons kaolin has been used as a critical raw material. Traditionally found in the rubber, paper, paint and ink industries, kaolin with further engineering supports more advanced applications such as automotive catalysts and tires, agricultural inputs, and wire and cable systems powering everything from data centers to the electric grid. In fact, this naturally occurring platy mineral, which was formed through the weathering of aluminum silicate minerals over millions of years, finds its way into just about everything that you use in your everyday life.
Properties of Kaolin
KaMin’s ability to engineer kaolin to meet exacting specifications makes it a versatile solution across industries. Its value stems from a unique set of physical and chemical properties:
- Purity: Naturally occurring kaolin may contain trace minerals, but through advanced purification methods, KaMin produces high-purity grades that influence the final applications in areas such as color (brightness and shade), viscosity, thermal stability, or regulatory compliance.
- Shape and Particle Size: Shape and particle size influence end-product performance - from the smoothness of coatings in paint, paper and packaging applications to the ability to control porosity and high-performance tires and barrier applications.
- Surface Chemistry: While kaolin particles are effectively insoluble and generally inert, kaolin’s surface chemistry can be engineered to be hydrophilic (water-loving) or hydrophobic (oil-loving), improving compatibility with other ingredients in the end product.
- Thermal Stability: Kaolin’s crystal structure allows it to withstand high heat flux, making it ideal for high temperature applications. Purity and crystal type have some influence on the final properties in the end application.
- Engineered Absorptive Capacity: Kaolin can be engineered to introduce pores of varying sizes and surface chemistry so that it can be used to absorb various materials in applications such as cosmetics (e.g. facial masks), agriculture (e.g. time release chemicals), or other similar applications.
- Organic: In its native form, kaolin is considered an organic material, making it ideal for applications such as cosmetics, agriculture, and personal care.
How is Kaolin Formed?
Kaolin forms naturally through the chemical weathering of feldspar-rich rocks such as granite or sandstone in a process that occurs over millions of years. The formation of kaolin on the surface of the rocks is called a primary deposit, which is often blended with sand or other minerals. The transformation results in kaolin deposits that vary in quality and characteristics depending on the region and geological conditions. Over time, erosion carries these particles to new locations where they settle into more highly purified, larger deposits called sedimentary deposits.
KaMin sources kaolin from sedimentary deposits in both Georgia and Brazil, where two of the highest quality reserves of kaolin can be found. Formed during the Cretaceous, Paleocene, and Tertiary periods, our Georgia deposits have unique properties. Our Brazilian sedimentary deposits are from the Tertiary Period.
How is Kaolin Processed?
At KaMin, kaolin processing is more than a series of steps—it’s a science-based approach engineered to finely tune one of the earth’s most versatile minerals into a high-performance solution for our customers’ needs. KaMin’s vertically integrated process ensures quality, consistency, and customization at every stage—from mineral discovery to delivery of the solution you need.
1. Locating Quality Kaolin Reserves
KaMin geologists conduct advanced drilling surveys to locate the highest-quality kaolin deposits by targeting material with the ideal blend of core attributes that can be engineered efficiently into a product.
Our sedimentary reserves in Georgia are found along what is known as the Fall Line, where millions of years ago kaolin was deposited as it was moved along streams and rivers. These are some of the highest quality reserves in the world. KaMin has five processing plants strategically located along the Fall Line, so all different types of crudes needed to deliver performance are readily available for our plants.
In Brazil, the largest premium deposits are found on the banks of the Jari River in the Amazon region in the northeastern section of Brazil and are mined exclusively by KaMin’s partner company, CADAM. Much like Georgia kaolin, these deposits are known for their high purity allowing key attributes to be dialed in during processing.
These locations coupled with our investments in specific processing equipment ensure consistent quality and performance in all our kaolin products.
2. Extraction and Stockpiling
Once identified, crude kaolin ore is extracted and transported to nearby processing facilities. To ensure precise blending and batch control, stockpiles are carefully organized by grade, which includes size, shape, and elemental content.
3. Crushing and Slurrying
Crude kaolin is delivered from the pile according to a recipe, processed through a crusher, and dispersed in water using a high-speed mixer, which creates a fluid clay slurry that allows impurities to be separated efficiently in downstream processes. This process of taking a kaolin ore and processing it by first slurrying allows for more complete impurity removal and is known as the water wash process.
4. Grit and Impurity Removal
The kaolin slurry then passes through a process known as degritting, which removes coarse particles and grit, such as sand particles. At select facilities, we also use chemical separation tanks to isolate and eliminate additional impurities like feldspars and mica. The ability to remove even low levels of sand from our kaolin ore is one reason all our materials are well below any regulatory threshold for silica (< 0.1% silica).
5. Purification and Refinement
From here, the purified slurry enters plant storage tanks, where it undergoes a series of advanced refinement steps:
- Centrifuges classify particle weight and accordingly size for optimal application performance.
- High-strength magnets remove free iron ilmenite and, if present, titanium dioxide.
- Ozone oxidation breaks down naturally occurring organic material for better whiteness and /or oxidizes iron contaminates so it can be removed in a later step.
- Leaching is a chemical reduction process that solubilizes surface iron on the kaolin particle so it can be removed in a later filtration process. Other trace elements such as soluble calcium and magnesium are also removed in filtration.
6. Dewatering and Drying
Once purified, the slurry is mechanically dewatered using rotary vacuum filters, which reduce water content and remove any process additives that aren’t desired in the final application. For dry product applications, spray dryers are used to dry the product into beads that can be effectively shipped without creating dust and whose moisture levels are typically less than 3% and can be produced at below 1.5% for moisture sensitive applications.
7. Hydrous or Calcined
Depending on the product formulation, refined “hydrous” kaolin either remains in dry and slurry form or is further processed in a calciner, where heat is used to convert the hydrous form of kaolin to the anhydrous form, calcined kaolin. Calcined kaolin can be used to deliver enhanced opacity, whiteness, durability, thermal insulation, or as a carrier for other materials in agriculture applications.
8. Final Packaging
From the mine, through the plant, to finished product, KaMin is focused on ensuring our customers’ needs are met with precision and reliability. Every stage of the process is closely monitored to ensure control, consistency, and performance. Rigorous quality assurance testing is in place to verify that our engineering controls are working as designed. Finished products are then packaged and delivered in the most cost-effective form according to customer needs:
- Bagged for smaller batch use
- Loaded in bulk hoppers or trucks for large-scale industrial application
9. Global Distribution
Our products touch every corner of the world with distribution extending from our customers in Georgia to more than 70 countries. As the 35th largest exporter in the United States, we prioritize delivering our solutions in the right package and through the right vessel—whether by container, truck, or rail—to meet the needs of our customers with precision and efficiency. With strategically located distribution hubs worldwide, KaMin ensures consistent quality and reliable delivery—on time, every time.
