Kaolin is an ideal additive to rubber due to its anisometric ‘booklet’ particle structure which adds strength and stiffness to the product through enhanced stress transfer. Kaolin clay is a low cost substitute for precipitated silica and carbon-black in certain compounds without sacrificing physical properties.Kaolin clay is used to improve the tensile and modulus of ground calcium carbonate based rubber compounds. ‘Soft’ kaolin clays have larger grain sizes and are used where high loadings (for economy) and faster extrusion rates are more important than strength. ‘Hard’ kaolin clays with smaller particle sizes impart high modulus, high tensile strength, stiffness, and good abrasion resistance to rubber compounds. 80% of the clays used in rubber production are Air Float hard clays, which are air separated to remove impurities. Surface treated hard clays provide even better reinforcement than untreated clays and has the capability to substitute carbon-black in certain applications.

Special functionalities such as improved air-permeability can be imparted in hydrous kaolin clays through the process of delamination. Calcined kaolin or water washed clay, is used in certain applications such as wire and cable manufacturing as it provides good reinforcement, better colour and higher volume resistivity.

China clay is widely used as filler in paints,coatings and printing inks. Not only its high chemical resistance is required, but also theform and the charge distribution of the particles, because they have a positive impact on final products. They affect rheology, sedimentation and thixotropy and give better processing properties to coatings or paints.

Over a hundred years ago it has been frowned upon to add fillers to paper. One even spoke of fraud. But by and by it was found that fillers are not only fibre replacements, but they also provide positive characteristics to paper such as drainage acceleration and constant rheological behaviour. Paper became non-transparent, whiter, received a closed, smooth surface. Moreover it became softer and more flexible. The main requirements for fillers are: low price, white colour, water insolubility and optimum fine dispersion. China clay has all these properties and additionally it is resistant to changes of pH-value. At the beginning of the papermaking the process pH-value was acidic; the current trend is to neutral or alkaline process pH-values. This allows an increased use of calcium carbonate, which is cheaper than china clay, but decomposes in acidic media. Therefore china clay is more and more displaced from its dominant position, but it still will continue to play a significant role in paper coating.

Kaolin is becoming more prevalent in porcelain insulation due to its high dielectric strength. Kaolin is used in refractories due to its extremely high fusion point, low water content and high green strength. Ceramics produced with kaolin have a wide variety of uses – primarily as a metal substitute. Ceramics are becoming more prevalent in aerospace due to their refractory strength. Ceramic knives stay sharper longer and have better durability than metal.

China clay is also used in agriculture: agricultural films protect little plants from drying out and minimize heat emission during cold weather periods or overnight. These films also prevent plants from soil contamination, so harvested plants are clean. But what is done with the films after using? By adding china clay they disintegrate into smaller particles used as mulch. With UV stabilizers properties of films can be regulated, that way that they retain strength during growing season and decrease strength rapidly afterwards. In greenhouse films also calcined china clay is widely used: heat radiation is reduced by IR absorption and consequently savings on heating costs are achieved. Despite the addition of china clay aging resistance and tensile strength of films are nearly not affected.

Raw China clay (Kaolin) is used in cement industries. This raw China clay (Kaolin) is reach in alumina. Also having low Iron, Titanium & chromium & that’s why very much suitable for cement application.

China clays are one of the most important raw materials used in the sanitary ware to give desired properties to SANITARY bodies during technological processes. They are a sinter-aiding agent as well, due to presence of mica and its thermal transformation characteristics. Depending on final product and kind of technology, several clay parameters are important: rheological qualities, plasticity, green and dry strength, sintering temperatures, etc.