Wet vs Dry Grinding and Reading d10, d50, d90

Wet vs dry grinding: the trade-off

Dry grinding runs without liquid; it is simple and needs no drying, but heat and dust rise and fineness plateaus early. Wet grinding suspends the product in a liquid with media, controls temperature, and reaches sub-micron and nano sizes far more reliably - at the cost of a later dewatering step. For most pigment, ink, battery, and agrochemical work, wet is the practical route to fine, uniform particle size. The media basis is in bead mill media: zirconia vs glass vs steel and bead sizing in grinding bead size selection.

What d10, d50, d90 mean

These are percentile diameters from the particle size distribution. d10 is the size below which 10% of the mass lies; d50 (the median) is the size below which half the mass lies; d90 is the size below which 90% lies. They describe spread, not just average. A tight distribution (d90 close to d50) means few oversized particles - critical for gloss, rheology, and hiding.

Wet vs dry at a glance

Factor	Dry grinding	Wet grinding
Fineness reach	Moderate	Sub-micron to nano
Temperature control	Poor	Good (jacket cooling)
Dust	Yes	No (slurry)
Post-step	None	May need dewatering
Best for	Coarse, heat-stable	Ink, coating, battery, SC

Reading the numbers in practice

Set your spec on d90 (worst oversize drives speckle and filtration) and watch d50 for the target fineness. When d90 drifts up, check media wear, separator, and residence time -细节 in how a bead mill works, grinding efficiency factors, and nanoscale bead milling. The bead mill selection guide ties fineness to chamber and media choice.

Frequently asked questions

Which is finer, wet or dry grinding?

Wet grinding reaches much finer, more uniform particle sizes and controls temperature; dry grinding is simpler but plateaus earlier and runs hotter.

What does d50 mean?

d50 is the median particle size: half the mass is finer, half coarser. It is the central fineness number, but alone it hides spread.

Why care about d90?

d90 captures the oversized tail. A few large particles cause speckle, poor gloss, and filter clogs even if d50 looks fine.

Is dry grinding ever better?

For coarse, heat-stable, dust-tolerant products it saves the dewatering step; for fine pigment and battery slurries, wet wins.

How do I measure these?

Laser diffraction on a sampled slurry is standard; pair the reading with a fineness gauge for production checks.

What widens the distribution?

Worn or wrong-size media, separator bypass, and short residence time let coarse particles through and push d90 up.