Kaolin, one of the most versatile mineral of the planet
The kaolin or kaolinite is a white, soft and plastic clay, composed mainly of fine-grained laminar particles. Its name comes from the first deposit discovered in China, Kaoling Hill. It is formed when anhydrous aluminium silicates found in feldspar rocks, such as granite, are disturbed by the weather or by hydrothermal processes. It is part of the group of industrial minerals, with the chemical composition Al2Si2O5(OH)4.
It is distinguished from other clays mainly by its softness, whiteness and easy dispersion in water and other liquids. These features are crucial for their uses in papermaking and other industrial applications of mineral fillers.
The kaolin is formed when the anhydrous aluminium silicates found in feldspar rocks, such as granite, are altered by the weather or hydrothermal processes. The process that turned hard granite into the soft matrix found in kaolin pools is known as "kaolinization." Quartz and granite mica remain relatively unchanged while feldspar is transformed into kaolinite. Smectite can also be formed in small amounts in some deposits.
The kaolin has multiple variations in its physical appearance, which influences its subsequent uses. It is utilized in many applications, as it is a unique industrial mineral, which remains chemically inert over a relatively wide pH range and offers excellent coverage when used as a pigment or diluent in coated films and filler applications. In addition, it is soft and non-abrasive and has a low conductivity of heat and electricity.
Paper
Kaolin serves as a filler and pigment in paper´s coating. It gives opacity and reduces pores, therefore, improves printing. Its use allows a reduction in the amount of expensive wood pulp required, improves the optical properties of the paper and its printing features. When used as a coating on the surface of the paper, its whiteness improves the brightness and opacity of the paper. In addition, the size and shape of single kaolin particles give the brightness and quality of the printed paper required for many different types of paper (like those necessary for magazines, leaflet, cartons or boxes, among others). Follow the link to see or visualize the different types of kaolin.
Sanitary ceramics
Kaolin has been designed with specific technical specifications for this market. It provides strength and plasticity in the formation of these products and reduces the amount of pyroplastic deformation in the cooking process. Follow the link to see or visualize the different types of kaolin.
Ceramic enamels
Refractory kaolin is used that raises the temperature of the enamel, providing very good plasticity, a high concentration of alumina (Al2O3) and good whiteness. Follow the link to see or visualize the different types of kaolin.
Crockery and porcelain
Kaolin used for crockery and porcelain, apart from the strength and plastic qualities, is essential to achieve high whiteness. This is because it includes a low content of colouring elements such as iron and titanium. Follow the link to see or visualize the different types of kaolin.
Rubber
Dry and powdered kaolins with a maximum humidity of 1% are used. They are utilized as load and filler, giving strength, abrasion and stiffness, reducing cracking. Calcined kaolin, in particular, with or without a chemical treatment of silane surface, is widely used in thermoplastic elastomers of high value for a variety of applications and in rubber insulation in high voltage lines. Follow the link to see or visualize the different types of kaolin.
Plastic
Kaolin serves as filler and load, giving a very fine final surface, reducing cracking and contraction of rubber. Improves thermal stability, resistance to impact and chemical attacks. It is also used as a rheological modifier and functional filler, thanks to its ability to improve mechanical, electrical and thermal properties. One of the most important applications is in the manufacture of PVC cables, where its main function is to improve electrical properties. Other important applications include special films in which it provides anti-blocking or infrared absorption characteristics. Chemically treated calcined kaolins are one of the main additives used in the manufacture of automotive parts based on engineering thermoplastics. Follow the link to see or visualize the different types of kaolin.
Printing inks
Kaolin is the main inorganic pigment used in this sector. Improves ink retention. Due to its low abrasion, it is a very good extender. It has low oil absorption so it modifies the brightness. Follow the link to see or visualize the different types of kaolin.
Paintings
Kaolin is used as a load and extender. It is inert to chemical agents, odourless, electrical insulator and with high coating. It has low viscosity in high percentages of solids. Kaolin is particularly useful as a partial replacement for TiO2 pigment. Follow the link to see or visualize the different types of kaolin.
Adhesives and glues
Kaolin can replace much higher price loads. Long-term economic stability. Follow the link to see or visualize the different types of kaolin.
Ecological agriculture
Kaolin is used as a protector against fly pests and mosquitoes. It covers the crops, reflecting the sun's ultraviolet and infrared radiation and decreasing evapotranspiration. It is diluted in water in an amount of 40 to 60 Kg / 1.000 L of water. It is used in organic farming. Follow the link to see or visualize the different types of kaolin.
Soil correctors
Kaolin is used for the improvement of adequate physical-chemical conditions to maintain a stable, aerated, absorbent agricultural soil, with high water retention capacity and allowing the ideal development of roots. Follow the link to see or visualize the different types of kaolin.
Cosmetics and personal care
Kaolin provides opacity, with absorbent benefits, giving softness and firmness to the skin. Follow the link to see or visualize the different types of kaolin.
Pharmacopoeia
It is used as an excipient in several formulations, like the preparation of medications to treat digestion problems and as a component of poultices. In addition, it is found in various dietary products, plasters, foot powders and in the specialized treatment of some lung disorders. Follow the link to see or visualize the different types of kaolin.
Sludge treatments
Kaolin is used to prepare mud for therapeutic or aesthetic treatments in spa centers. It is also used as an excipient in thalassotherapy products (bath and skin treatments). Follow the link to see or visualize the different types of kaolin.
Food
Kaolin is used in cattles´s feeding, as an anti-caking agent and anti-humectant avoiding fungal cultivation. Follow the link to see or visualize the different types of kaolin.
White cement
Kaolin is used for the preparation of this type of cement, widely used both in prefabricated pieces and in floor and brickwork finishes in general. Follow the link to see or visualize the different types of kaolin.
Mortars
Kaolin presents as a mortar constituent. Follow the link to see or visualize the different types of kaolin.
Stucco
Kaolin is part of the mixture, along with gypsum, which produces stucco. Follow the link to see or visualize the different types of kaolin.
Refractories
Refractories are produced from natural materials. It is the combination of compounds and minerals such as kaolin, which are used to build structures subjected to high temperatures, from simple products to sophisticated products. From chimney brick cladding to thermal re-entry shields for a space shuttle. Follow the link to see or visualize the different types of kaolin.
Fibreglass
Fibreglass used as reinforcement in a multitude of applications requires the use of kaolin for its production. Kaolin allows the strengthening of the fibres integrated in the material. It also improves the integration of fibres into products that require reinforced plastics: auto-mobiles, boats and marine products, sporting and recreational items, aviation and aerospace products, circuit board manufacturing, fibreglass insulation, fibre air filters glass, tanks and pipes made of fibreglass, corrosion resistant glass fibre, etc. Follow the link to see or visualize the different types of kaolin.