ACM pulverizer (air classifying mill) is an integrated impact grinding + dynamic air classification machine. It is designed for dry, brittle, free-flowing feedstock. Material breaks under high-speed hammer impact. Ductile, elastic, sticky or long-fiber materials will not fracture properly and tend to cause equipment fouling. Fineness range typically 120–800 mesh, adjustable by classifier speed, hammer count, airflow and rotor tip speed.
Processable Materials
1. Non-metallic minerals (main application)
Calcium carbonate, talc, kaolin, diatomaceous earth, quartz, feldspar, wollastonite, barite, gypsum, dolomite, marble, iron oxide, titanium dioxide, alumina.
For diatomaceous earth, low-impact settings are used to preserve frustule porous structure. Hard silica needs ceramic / tungsten carbide wear liners to avoid metal contamination.
2. Battery & flame retardant inorganic powders
LFP, NCM, LCO cathode materials, ATH aluminum hydroxide, magnesium hydroxide, precipitated silica, calcined graphite, ceramic raw materials.
Combustible battery powders require nitrogen inerting, anti-static grounding and explosion protection. Abrasive grades accelerate wear parts consumption.
3. Brittle metal & precious metal fragments
Ruthenium, tungsten, molybdenum, brittle metal alloys, various metal oxides.
High density demands higher transport airflow to prevent powder deposition. Wear-resistant liners and full dust containment are mandatory for toxic/noble metal dust.
4. Powder coating raw materials
Extruded polyester, epoxy, hybrid powder coating chips, dry inorganic pigments, low-wax organic pigments.
Heat-sensitive resin requires water cooling jacket to prevent melting, wall sticking and premature curing. Excess hammer count generates extra heat and unwanted ultrafine fines.
5. Agro, food & mineral additives
Agricultural grade diatomaceous earth, food-grade calcium carbonate, calcium phosphate, mineral feed supplements, brittle shell powder.
Food/pharma versions adopt polished stainless steel and easy-clean structure. High-oil plant materials are not suitable.
6. Industrial fillers, pigments & ceramic raw materials
Inorganic color pigments, extender fillers, calcined clay, ceramic body raw materials.
Unsuitable Materials for ACM Pulverizer
- Ductile / malleable metals: soft aluminum, soft copper. They deform and flatten instead of breaking into powder.
- Long fibrous materials: wood fiber, cotton, hemp, long plant fibers. Fibers wrap rotor and classifier wheel and trigger vibration and blockage.
- Sticky, high oil or high moisture feed: wet clay, high-fat plant powder, sticky resin. They stick to chamber walls and blind classifier/filter bags. Feed moisture should generally be controlled below 3–4%.
- Elastomers / soft rubber: absorbs impact energy and cannot be pulverized into fine powder.
Key selection principles
- Brittleness: core requirement. Material must fracture under impact; bending or deformation means ACM is not a good fit.
- Mohs hardness: optimal range Mohs 1–5. Materials above Mohs 5 can be processed but wear part cost rises sharply, requiring carbide or ceramic protection.
- Heat sensitivity: organic materials need water cooling; higher hammer count creates more heat and ultrafine fines.
- Safety constraints: combustible, toxic or oxidizable powders require inert gas, static elimination and explosion relief design.
ACM pulverizer can grind dry brittle materials including non-metallic minerals, battery inorganic powders, brittle precious metal fragments, powder coating resin chips, agro-mineral fillers and inorganic pigments. It cannot handle ductile metals, long fibers, sticky or high-oil substances. Hammer setup, rotor tip speed and wear protection are tuned according to material hardness and brittleness to reach target particle size.
