Mineral industry ACM mill (air classifying mill) is heavy-duty impact grinding equipment with built-in dynamic air classification, widely used for dry processing of non-metallic minerals. It can continuously produce powder with fineness adjustable from 120 mesh up to 800 mesh. Operators adjust hammer count, rotor tip speed, airflow and classifier wheel speed to control particle size, throughput and fines yield. Wear resistance is the core design consideration for mineral processing, as many mineral ores are abrasive.
Typical Mineral Processing Applications
- Carbonate minerals
Calcium carbonate, limestone, dolomite, marble. Used as fillers for plastic, rubber, paint, paper and construction materials. - Silicate minerals
Talc, kaolin, wollastonite, mica, feldspar, diatomaceous earth.
Diatomaceous earth requires gentle grinding parameters to preserve the porous frustule structure and avoid crushing the shell skeleton.
- Sulfate minerals
Barite (barium sulfate), gypsum, anhydrite. Barite powder is widely used for oil drilling weighting agent and paint filler. - Oxide minerals
Quartz, iron oxide, alumina, titanium dioxide. Hard quartz needs full ceramic or tungsten carbide wear liners to reduce metal contamination and extend service life. - Other industrial minerals
Fluorite, potash ore, mineral soil amendments, mineral feed additives.
Fineness Range for Mineral ACM
- D50: 18–65 μm
- D97 adjustable: 120 mesh ~ 800 mesh
- Coarse grade (120 mesh): high throughput, less fines, maximum production capacity
- Medium grade (325 mesh): most common commercial filler grade
- Fine grade (800 mesh): higher specific energy consumption, increased internal recirculation
Mineral Grade ACM Construction Requirements
- Wear protection is the priority:
For abrasive minerals (quartz, feldspar): rotor hammers, liner plates adopt tungsten carbide or alumina ceramic.
For soft minerals (talc, diatomaceous earth, calcium carbonate): ordinary alloy steel is acceptable. - Product contact parts: carbon steel or alloy steel; if high whiteness is required, use stainless steel plus anti-wear lining to avoid iron contamination.
- Heavy-duty base frame: withstand continuous vibration and heavy load during long-time non-stop production.
- Negative pressure dust collection system to capture large volume of mineral dust and prevent fugitive dust emission.
Operational & Temperature Control
- Standard mineral processing runs without water cooling; outlet temperature normally 40–60°C, fine grinding can reach 55–70°C. Minerals are thermally stable, so this temperature range is acceptable.
- Hammer count selection:
- Coarse products (120 mesh): fewer hammers to maximize throughput and reduce energy consumption.
- Fine products (325–800 mesh): more hammers to increase impact events and generate enough fine particles, but noise and power consumption rise.
- Feed moisture limit: ≤3–4% to prevent agglomeration and wall buildup.
- Airflow: higher airflow for coarse grades; reduce airflow for fine powder to extend particle residence time.
Safety & Auxiliary System
- Vibration and temperature interlock protection for bearings.
- Large pulse baghouse with ePTFE membrane filter bags, higher pulse frequency for fine mineral powder.
- Compressed air system for filter cleaning, 0.5–0.7 MPa.
- Noise control: noise level 82–90 dB(A) at 1m; acoustic enclosure optional.
Limitations
- Only for dry brittle minerals; wet mineral slurry cannot be processed.
- Extremely hard minerals (Mohs >6) can be ground but wear parts cost will increase significantly.
- Fibrous minerals may wrap rotor and classifier wheel and cause unstable operation.
Mineral industry ACM mill is heavy-duty dry grinding equipment for non-metallic minerals such as calcium carbonate, talc, kaolin, diatomaceous earth, barite and quartz. It produces mineral powder from 120 mesh to 800 mesh. Wear-resistant liners are configured according to mineral abrasiveness. Hammer count, rotor tip speed and airflow are adjusted to balance throughput, particle size and energy consumption.
