China clay (also known as kaolin or kaolinite) is a versatile industrial raw material used in various industries, including ceramic/porcelain industry, paper industry, paint industry, soap, cosmetics, pesticides, toothpaste, rubber, and other household appliances. While this material was discovered in China (hence, the name), it can also be found in many areas, especially those near a volcano. 

Due to the large number and type of kaolin industries in the manufacturing process, this material has become a widely demanded commodity in the mineral industry. Indonesia has one of the busiest kaolin mines in South East Asia. Experts predict that Indonesia has approximately 66.21 million tons of kaolin reserves over several strategic areas, including West Kalimantan, South Kalimantan, Bangka Belitung, Sulawesi, and East Java.

China Clay Mining

china clay mining activity illustration

Kaolin is typically produced using two different methods; Open Mining and Hydraulic Mining. The first method is carried out by conducting a massive, heavy excavation of the ground layer after peeling off the soil. This conventional method is widely used by mining contractors all over the globe. 

Meanwhile, Hydraulic Mining is carried out by spraying water to the soft underground sediment using a high-pressure water jet. This way, the rock or sediment material will come out on its own after a specific time in the form of kaolin mud.

Hydraulic Mining relies on the nozzle of its high-pressure water jet since the device has a vital role in controlling the direction of water, velocity, mass, shape, and pressure of the fluid as it exits and enters the pipe or tube. While this method is fast and effective, it can cause severe environmental damage by causing flooding, erosion, and leaving a pile of sediments that can block waterways.

Related: Get Insight: Step-by-Step Procedure of Kaolin Mining Industry

China Clay as Filler Component

Industrial manufacturing often uses a combination of minerals, raw materials, and chemicals to produce something. Thus, any industry will always need a constant supply of filler components. In a simpler term, filler components are additional materials added within a production process to improve specific properties. The use of filler will make the product cheaper while retaining its original purposes or properties.

There are a lot of filler components, explicitly used for specific industries. Calcium carbonate, magnesium carbonate, barium sulfate, and barite are just small examples compared to the exact number of all components used as filler.

Related: Types and Usage of Kaolin Filler You Should Know

Why Use China Clay as a Filler Component?

Kaolin can be used as an excellent filler in many industries. Here are five reasons why:

1. Adding Volume and Strength

Filler is an integral part of any manufacturing process that aims to increase volume or strength. Luckily, kaolin fits this role perfectly since it can add more volume and increase the hardness, tear resistance, abrasion resistance, or even breaking the tension of finished products. Ceramic and household appliances are two areas that often use kaolin as a filler component for this specific purpose.

To further elaborate, the production of ceramic products itself uses various raw materials to produce different product characteristics. Materials such as sedimentary clays, schistous clays, and characteristic clays are commonly used to create bricks, tiles, and clay pipes. 

Additive materials, such as sawdust, paper binders, plastics, and kaolin can be added to obtain a larger production volume. Metallic oxides are added to bring the desired color for bricks and tiles production, while kaolin is added to enhance strength and hardness.

2. Reducing Production Cost

Typically, companies are always looking for cheaper raw material suppliers. Thus, the use of fillers is intended to reduce general production costs without further reducing the quality of the end product. 

Kaolin prices are meager, making it very profitable for any industrial purposes. Kaolin helps increase the volume of production, both as active or inactive material. For example, in the paints and pesticides manufacturing process, manufacturers can produce more products in less time and use more efficient raw materials when kaolin is added as a filler compound.

Versatile Use in Various Industries, including Pharmaceutical or Cosmetic Industry

Usage of china clay or kaolin in various industries

The versatile mineral can be adjusted based on the needed specification. For instance, kaolin has been widely used as a traditional medicine for thousands of years. It functions as an active ingredient for long and short-term treatment. 

The mineral can be administered orally as an antibacterial, antiviral, and antidiarrheal or topically as a dermatological protective agent. Apart from being an active ingredient, kaolin is also commonly used in pharmaceutical applications as an excipient or filler, emulsifying agent, suspension agent, and disintegrant.

Apart from pharmaceutical applications, kaolin or China clay is also used in the cosmetics industry. There is quite a selection of kaolin-based products in the market, starting from face clay masks to whitening toothpaste.

1. Safe to Use in Biomedical and Pharmaceutical Fields as Chitosan Filler

Kaolin is one of the most popular layered silicate materials that has been used in chitosan-based nanocomposites due to its low cost and availability. Kaolin as chitosan filler functions as a neutralizing and reinforcing material in the manufacturing process. It can prevent the release of negative ions in CuO metal since kaolin contains mineral elements such as Na+, K+, Mg2+, and Ca2+.

Chitosan is a linear chain of D-Glucosamine and N-Acetyl D-glucosamine. The deacetylation of chitin produces it. Because in the cationic form, the water-insoluble form of chitosan will form polyelectronic with polyelectrolyte anions. Chitosan has been used in the biomedical and pharmaceutical fields since this material is biocompatible, biodegradable, and non-toxic.

2. Great for Rubber Compound Production

In the rubber industry, kaolin is widely used as an additive to increase volume and rubber hardness (strength). Different sizes and amounts of kaolin have other effects on the hardness, elongation, and abrasion resistance of rubber compounds. The test results on rubber compounds using kaolin as filler are better than using other filler compounds in the market.

The optimum addition of China clay will increase the tensile strength, tear resistance, abrasion resistance, and flexural cracking. To obtain optimum reinforcement, the filler must be spread evenly in the compound.

Final Words

With proper utilization, kaolin or China clay can be used as a filler in almost all strategic industries, including the health, food, and beauty industry. Considering the low market price for kaolin, this mineral is amazingly effective in reducing production costs while maintaining the quality of the end products.