Learn About Jet Mill
Jet mills, or air jet mills, have a unique feature. They don’t require mechanical grinding tools. The particles crush and grind in a gas stream. They collide with each other repeatedly. Jet mills are an excellent choice in industry when ultra-fine grinding is required. They are suitable for dry and very hard materials and it is possible to achieve finenesses down to d97 = 1 µm with them.
Working Principle of Jet Mill
In a jet mill, compressed air enters the grinding chamber through special nozzles. The air is accelerated so much that it carries the particles along. The particles collide with each other many times, which breaks them down. A big advantage of this mill is that it has no mechanical grinding tools. This means the particles don’t touch anything, so there is no wear. This is why jet mills are excellent for very hard materials or materials that have to be as pure as possible. In a downstream cyclone separator or dust filter, the grinding gas removes finely ground material.
Jet milling is a key service offered by toll processing companies. It’s a process that reduces particle size. Many industries need it, like pharmaceuticals, cosmetics, paints, pigments, and industrial chemicals.
This milling method uses high-pressure gas. It creates fast collisions between These collisions fracture the particles into smaller pieces.
Jet milling can reduce particle size and classify them in one step. These mills can finely grind friable materials including polymers, chemicals, and ceramics. Abrasive materials can be processed on this equipment without contamination.
A skilled tolling expert can optimize the jet milling process. This allows for achieving even smaller particle size ranges. Temperature-sensitive products can also do well.
Jet mills can even be used to blend some powders. Two or more streams of material can be fed into the mill, resulting in a homogenous blend.
Six Types of Air Jet Mill Products
Fluidized Bed Jet Mill
Lithium Battery Material Fluidized Bed Jet Mill
Non-metallic Mineral Fluidized Bed Jet Mill
Inert Gas Spiral Jet Mill
Chemical Spiral Jet Mill
Laboratory Fluidized Bed Jet Mill
Types of Jet Mills
Based on how they control the final particle size, jet mills are designed in one of two ways:
- Fluid bed jet mills feature air classifiers. These can be finely tuned to achieve the exact particle size and shape you need.
- Circular jet mills, or spiral jet mills, classify materials inside the grinding chamber.
Both mills are free of moving parts in the grinding chamber. This significantly reduces wear and tear on the equipment. It also makes cleaning and sanitization easy. This greatly reduces the risk of cross-contamination.
How Does Jet Mill Work?
The process doesn’t create heat like mechanical milling. So, softer powders and sensitive materials work well. Jet milling is a great choice when precision is important. It achieves uniform particle sizes, which is very appealing.
In circular and fluidized bed mills, jets of air or steam form from compressed gas. This gas has a gauge pressure of 50 to 120 psig. The most common gas used is commercially compressed air.
Superheated steam (392–980°F) can be compressed to 100–220 psig. This steam is useful for certain raw feed materials that don’t easily heat up. Some of the other gases used include:
- Nitrogen, which can protect materials from oxidation and/or fire
- Argon, another inert option, though more expensive than nitrogen
- Helium, used to achieve higher-velocity impact between particles
A great deal of energy is needed to create enough momentum to cause particles to break on impact. The compressor and nozzles change high air pressure into kinetic energy in the mill. Large particles recirculate, and multiple high-velocity collisions progressively reduce their mass.
At this point, the differences between circular and fluidized bed mills become clear. In a circular mill, small particles are less affected by centrifugal force. As they’re reduced in size, they migrate toward a central outlet in the milling chamber.
In the fluid bed mill, smaller particles move up to the central discharge port. A centrifugal classifier now lets the right-sized particles pass through the port. Larger particles return to the bed for further reduction.
Jet Mill Feature
Inert gas closed-circuit cycle/explosion-proof design, which can meet the grinding of flammable, explosive, easy to oxidize, and easy to absorb moisture materials.
The grinding form of fluidized bed collision can better maintain the shape of particles.
Low temperature and medium-free grinding, suitable for heat-sensitive, low-melting, sugar-containing, and volatile materials.
High-temperature and high-pressure grinding to achieve higher injection speed, lower dynamic viscosity, and higher grinding fineness and efficiency.
The grading wheel is installed horizontally, which can better control the fineness of products with low density and produce finer products.
Application Areas of Jet Mill
At present, air flow mills are widely used in the following industries: Pesticides, Pigments, Talc, Chemicals, Loose powders, PE wax, LFP, Active Charcoal, Agrochemicals, Ceramic, Catalyst, Ceramic Pigment, Ceriumoxid, Dental-Frit, Dental-Glassceramic, Fumed Silica, Iron oxides, Iron Phosphate, PE Wax, Pigments, Polytetraflourethylen, PVDF, Silicon Carbide, Silicon, Toner, lithium carbonate, Lithium iron phosphate, Lithium manganese iron phosphate, Lithium cobalt oxide, Ternary positive electrode material, NCM, NCA, NCMA, Phosphor, Borax (boron oxide), molecular sieve, barium sulfate, ceramic glaze, Peek, antimony oxide, Strontium Nitrate, dental porcelain, muscovite, NdFeB, zinc oxide, yttrium oxide.
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Jet Milling Grinding Solution
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Who is EPIC Powder Machinery?
EPIC Powder Equipment Supplier，20+ years of work experience in the ultrafine powder industry. Actively promote the future development of ultra-fine powder, focusing on crushing,grinding,classifying and modification process of ultra-fine powder.
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