Alumina Grinding Media
Alumina grinding balls, cylpebs and micro beads for ball, bead and attritor mills — high density with minimal product contamination.
Media selection is a balance between three things that pull against each other: grinding efficiency, contamination of the product, and media cost per tonne milled. Getting it right usually cuts both the media bill and the milling time.
Choosing a size
As a rule, media should be about 20 to 30 times the size of the feed particle for effective breakage. Too large and you crush the mill lining while leaving fine material uncut; too small and the media cannot break the largest particles at all. In practice most mills run a charge with two or three sizes, and the ratio is adjusted as the feed changes.
Choosing a shape
| Shape | When to choose it | Trade-off |
|---|---|---|
| Balls | General grinding, standard mills, predictable packed density | Point contact can peen soft or flaky material |
| Cylpebs | Where more surface contact is wanted and peening is a problem | Slightly higher media wear at the edges |
| Micro beads | Bead and sand mills, fine and very fine grinding to sub-micron | Requires a tight size distribution to keep the PSD narrow |
Grade and wear rate
Alumina content drives density, and density drives grinding energy. AL-99 gives roughly 7% more bulk density than AL-92 and wears at roughly half the rate — which is why the higher grade frequently works out cheaper per tonne milled despite the higher purchase price. Where the product specification sets a contamination limit on iron, alumina media is usually the only option anyway.
AL-92
Bulk density 3.60 g/cm³. For coarse grinding where media cost dominates and contamination is not specified.
AL-95
The most widely used grade in cement, mineral and ceramic milling. Good wear rate at a moderate price.
AL-99
Bulk density 3.85 g/cm³, wear ≤ 0.05 g. For fine grinding, glaze milling and metals-free applications.
AL-99.7
For battery materials, pigments and technical ceramics where iron pickup is measured in ppm.
What we supply
- Alumina grinding balls, Ø10–90 mm, roll-formed and isostatically pressed
- Alumina cylpebs for reduced peening and higher surface contact
- Alumina micro beads, Ø0.5–10 mm, with a tight size distribution
- Matched mill lining bricks in the same grade as the media
- Charge-profile advice: tell us the mill dimensions, throughput and target fineness and we will propose a size mix
Ceramic grinding balls
- Al₂O₃ 92 / 95 / 99 / 99.7% by grade
- Standard diameters Ø10, 20, 30, 40, 50, 60, 70, 80, 90 mm
- Diameter tolerance ± 1.0 mm
- Wear loss 0.10 g (AL-92) down to 0.04 g (AL-99.7)
- Supplied in 25 kg bags, 1,000 kg jumbo bags or steel drums
- MOQ 500 kg for standard sizes
- Lead time 5–7 days ex works for stock sizes
Send us the current media size, charge weight and consumption in kg per tonne milled. We will calculate the alumina grade and size mix that gives an equivalent or better grind, and estimate the change in contamination.
Get a media recommendation
Mill type and dimensions, feed size, target fineness and current consumption — enough to specify the grade and charge.
In this section
Alumina Grinding Balls
The standard charge for ball mills where the priority is a predictable grind and metal-free product. Available in 92%, 95% and 99%…
Alumina Cylpebs
A cylpeb is a short cylinder with rounded ends. Compared with a ball of similar mass it presents more contact area per…
Alumina Micro Beads
Micro beads grind by contact area rather than by mass. The particle size distribution of the beads themselves becomes part of the…
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.