Alumina Micro Beads
Alumina micro beads from Ø0.5 to Ø10 mm with a tight size distribution, for bead, sand and attritor mills producing sub-micron particles.
Micro beads grind by contact area rather than by mass. The particle size distribution of the beads themselves becomes part of the product specification, because a wide bead distribution produces a wide grind distribution.
Where it is used
- Bead and sand mills producing sub-micron dispersions
- Ink, pigment, paint and coating milling where colour purity matters
- Battery cathode and anode material milling with ppm-level iron limits
- Pharmaceutical and food milling that must be metal-free
- Technical ceramic and electronic material preparation
Sizes and properties
| Diameter | Grade | Typical target grind | Mill type |
|---|---|---|---|
| Ø0.5 – 1.0 mm | AL-99 / 99.7 | sub-micron | High-energy bead mill |
| Ø1.0 – 2.0 mm | AL-99 | below 2 µm | Bead mill, sand mill |
| Ø2.0 – 3.0 mm | AL-99 | 2 – 5 µm | Bead mill, attritor |
| Ø3.0 – 5.0 mm | AL-95 / 99 | 5 – 10 µm | Attritor, small ball mill |
| Ø5.0 – 10 mm | AL-95 / 99 | 10 – 30 µm | Attritor, small ball mill |
Tight size distribution available on request — specify the allowable spread and we will quote to it. MOQ 100 kg; supplied in 25 kg bags or sealed drums for clean-room use.
Bead size and grind size
As a starting point, a bead diameter of roughly 1,000 × the target particle size gives an efficient grind in a high-energy mill. Beads that are too large leave fine material uncut; beads that are too small cannot break the coarse end of the feed, and the grind stalls. The practical answer is often a narrow two-size mix.
Contamination
AL-99 and AL-99.7 beads wear at 0.05 g or less and do not introduce iron into the product. Where a specification sets an iron limit in parts per million, we can supply the media wear figure in the same form so it can be entered directly into your contamination budget.
Get a bead size recommendation
Target particle size, mill type, chamber volume and existing media size — enough to specify the charge.
Send us your drawing — get a quotation with a firm lead time
PDF, DWG, STEP, IGES or a photo with the critical dimensions marked. Engineering review within one working day.