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Classifying with air classifier mills

Classifying is a processing application used when a tightly controlled particle size, distribution or top size is required or where there is a requirement to remove impurities from the raw material.
During the manufacturing process, classifying can be carried out as a separate operation, or it can be an integral part of the process by utilising an air classifier mill.

The air classifier mill process

An air classifier mill, also known as an air classifying mill, uses airflow to separate particles by size. The mill consists of a grinding chamber, a classifying wheel, and a fan.

The raw material to be ground is fed into the grinding chamber, which is impacted by a high-speed rotor fitted with hammers or pins. The size of the particles is then reduced by the hammers or pins, and the resulting powder is carried out of the chamber by the airflow generated by the fan.

The classifying wheel, located inside the grinding chamber, separates the particles by size. The wheel is typically made of a material such as ceramic or metal, and it is divided into several sections, each with a different size range.

As the powder exits the grinding chamber, it comes into contact with the classifying wheel. The fine particles pass through the smaller size ranges and are carried out of the mill by the airflow, while the larger particles cannot pass through and are collected in the larger size ranges.

Air classifier milling applications

Air classifier mills are used in various industries, including pharmaceuticals, chemicals, minerals, and food processing.

They are particularly useful for grinding heat-sensitive materials, as they do not generate heat during the grinding process. This is because the airflow cools the particles as they are ground, preventing them from getting too hot.

Additionally, they can produce a very narrow particle size distribution, making them ideal for applications that require a specific particle size.

The benefits of air classifying milling

There are several benefits to using an air classifier mill. One of the main advantages is that the mill can produce a very fine powder with particle sizes as small as 10 microns. This makes it ideal for applications that require a very fine powder, such as pigments, pharmaceuticals, and cosmetics.

Additionally, the mill can produce a very narrow particle size distribution, which is beneficial for applications that require a specific particle size.

Another benefit of the classification process is that it can handle a wide range of materials. Air classifier mills can grind materials that are very hard, such as minerals, and very soft materials, such as plastics. This makes it a versatile piece of equipment that can be used in various industries.

Air classifier mills are also easy to operate and maintain. The grinding chamber and classifying wheel can be easily disassembled for cleaning and maintenance. Additionally, the mill is designed to be energy efficient, and it consumes less energy than other types of size reduction equipment.

All Atritor mills are air-swept, passing the material through the system in the air stream. We are experts in bespoke classifying processes that solve the challenges that often arise when processing materials.

How can we help you?

Our experience in the industry has given us the knowledge to design and build classification processes that take raw materials and manufacturing bi-products and turn them into value-added products. Contact our team to discuss your material processing challenge or idea.