The jet mill (also known as Air Jet Mill) is an industrial device that utilizes the kinetic energy of high-speed airflow to achieve ultrafine grinding of materials. Since its invention in the 1930s, it has been widely applied in the chemical, pharmaceutical, and military industries. In the chemical sector, the air jet mill is highly valued for its unique grinding principle and advantages, making it an indispensable tool in the production of many fine chemical products. Specifically, the jet mill in chemical industry excels in processing heat-sensitive, explosive, or high-purity materials due to its low-temperature, contamination-free operation, which is critical for meeting stringent industry standards.
Working Principle and Features
The air jet mill works by particle–particle collisions, shear, and friction under high-speed airflow. This enables ultrafine grinding. The main process includes:
- Energy conversion: Compressed air at 0.6–1.2 MPa is accelerated to supersonic speed (300–500 m/s) through Laval nozzles, creating a high-speed intersecting airflow field at the center of the milling chamber.
- Grinding mechanism: Material particles collide, shear, and rub against each other under the action of high-speed airflow.
- Classification: Ground particles enter a classification system where fine powder is collected while coarse particles return for further grinding.
Key technical features include:
- No heat damage: The grinding process produces almost no heat, suitable for heat-sensitive materials.
- Low contamination: Can operate with inert gas to prevent oxidation.
- Ultrafine product size: Achieves micron or even submicron particle sizes.
- High automation: Modern systems often use PLC control for full automation.
Typical Applications of Air Jet Mill in the Chemical Industry
Inorganic chemical raw materials
Materials such as alumina, zinc oxide, silica, and calcium carbonate are ultrafinely ground to improve dispersion and reactivity in coatings, plastics, and rubber.
Organic chemical materials
Dyes, pigments, and pharmaceutical intermediates require high purity and stable dispersion. Air jet mills achieve the desired particle size. This improves coloring strength and reaction efficiency.
New materials
In lithium battery production, air jet mills process cathode materials such as lithium iron phosphate and ternary compounds. They can grind lithium iron phosphate to d98 = 1–20 μm. This meets the strict particle uniformity required for battery materials.
Additives
Surfactant carriers, flame retardants, and matting agents are ultrafinely processed to increase specific surface area and reactivity, thereby enhancing product performance.
High-purity and special materials
Many high-purity or special materials (such as cobalt powder, titanium compounds, and nitrides) require strict control of the grinding environment. Inert gas-protected air jet mills isolate materials completely from air, enabling safe processing in a closed environment. This is especially critical for flammable and explosive materials such as certain energetic compounds. In the pharmaceutical industry, inert gas jet mills preserve the activity of drug components, prevent oxidation, and improve both efficacy and safety.
Development Trends and Outlook
As the chemical industry advances toward higher precision and performance, the demand for powder fineness, purity, and particle size distribution continues to grow. Air jet mills, as advanced dry ultrafine grinding equipment, will play a key role in:
- Green production: Low-energy, contamination-free grinding aligned with environmental protection.
- Smart manufacturing: Integration of automated control and online monitoring to achieve real-time particle size regulation.
- Expanded applications: Extending from traditional chemical processing to emerging industries such as new energy, electronic information, and functional materials.
Epic Powder
With more than 20 years of expertise in ultrafine grinding, Epic Powder provides advanced air jet mill solutions tailored to the chemical industry. By combining precision engineering with innovative process control, Epic Powder helps enterprises achieve finer powders, higher product performance, and sustainable, intelligent production.
