Dry bead millContinuous

DRYSTAR
SIGMA DRY®

With built-in classifier®

Unique dry bead mill from the specialist,

in fine-particle technologies,

Ashizawa

SIGMA DRY
SGD12.5

DRYSTAR®

SDA5

Particle technology for co-creation of new possibilities

Ashizawa Finetech Ltd.

®

Continuous
dry bead mill

Grinding of high-hardness materials
down to single-micron level!

Superb energy efficiency and support for mass production
Dry and continuous-operation horizontal mill
■ Grinding of several hundred-micron materials down tosingle-micron with single pass
■ Minimizing of energy costs■Feature(one-tenth of jet mill *according to in-house research)

Minimal air consumption due to only using air for shaft
seal protecting■ Effective surface modification processing■Structure

FeederMaterial

Powder(Particles)

Air

Grinding Grinding
aidchamber

ScreenSpot dust
collector

Rotating
shaft

DRYSTAR®
Powder after
processing

Grinding data from DRYSTAR®
Processing example 1 Material: silica（Mohs hardness of 7）

AFTER

100μm

(Unit: μm)

15AfterBefore
singlepass of grinding
processing

10dMAX15520

d50

2.5140Frequency [%]BEFORE(Unit: μm)

AfterBefore
singlepass of grinding
processing

AFTER

100μmdMAX

9200d502.1

52100μm

Proven materials used with DRYSTAR®
Mohs hardness

520110100
Particle size [μm]1000Particle size distribution

15Frequency [%]BEFORE

After single passof processing

00.1

100μm

Processing example 2 Material: alumina（Mohs hardness of 9）

Particle size distribution Before grinding

10

After single passof processing

Before grinding

500.11

10100
Particle size [μm]1000

Materials

7 to 9Quartz, Silica, Soft ferrites, Hard ferrites, Alumina, Silicon nitride, Iron oxide, Tungsten oxide, Sodium silicate

4 to 6Glass, Carbon, Black silica, Blast furnace ash, Fly ash, Incineration ash, Organic germanium, Zinc oxide,Cerium oxide, Chromium oxide

Less than 4Gypsum, Magnesium hydroxide, Aluminum hydroxide, Barium titanate, PZT, Powdered green tea, Rice ﬂour,Activated carbon, Calcium carbonate

Dry bead millwith built-in classiﬁer

Achievement of high-level particle-size control!
Support for combination of grinding, dispersing,and classifying■Feature

Strong with grinding special pin shapeEfficient collection of fine particles based onloosening of particles agglomerated indispersing zone
■ Elimination of coarse particles based on adoptionof high-precision classifier■ Achievement of sharp particle-size distribution■■

Minimization of installation space
Speciﬁcations

Grinding data from SIGMA DRY®
<Differences in particle-size distribution resulting from adjusting of SGD12.5 classifier rotation speed and blower air volume>
10

原料material①②③④

Frequency [%]864200.1

110100Particle size [μm]Operatingconditions

Raw

Material: metallurgical silicon1000

Classifier
Air flowrotation speed（m3/min）（rpm）

Frequency [%]64200.1

1

10100
Particle size [μm]1000d50dMAX--

516.0

1408.0①3,000

46.1

37.0

②

5,000

4

3.7

19.0

③

7,000

4

2.6

11.0

④7,0002

1.58.0

10000

Raw
原料
material①②③④8(μm)Rawmaterial

10

Material: silica sandParticle size

10000

Operatingconditions

Particle size

Classifier
Air flowrotation speed（m3/min）
（rpm）

(μm)

d50

dMAX

Raw
material--

130.1

352.0

①3,00046.1

37.0②5,00043.318.5③7,000

4

2.3

11.0

④7,0003

1.5

10.1

Unitdiagram❶ Material
Feeder

SIGMA DRY®

Bag filter❺

AirCyclone

Load cell❹Classifyingzone❸

Dispersingzone❷

Grindingzone

Automatic
butterflyvalve

Automatic
butterfly
valve

BlowerLoad cell

Process ﬂow of SIGMA DRY® (model: SGD)

Detailed view

Discharging ofground material

Air

Dispersing zone

Grinding
media
Secondaryair

アジテータ

Cooling jacket

Classifying zone

Cooling jacket

Material
undergoing
grinding

Grinding zone

Shaft-seal air❶ The raw materials are supplied into

SIGMA DRY® through the constant feeder.
❷ The coarse particles are sent to the grinding
zone, and undergo grinding with beads.
❸ The powder that has undergone grinding isloosened with air flow in the dispersing zone,
and then is sent to the classifying zone.
❹ In the classifying zone, the fine and coarse
particles undergo classifying with the centrifuge
rotor.
❺ The fine particles are dispensed from
SIGMA DRY® and are collected with thecyclone and bag filter.
Processing is continuously carried out by repeating
steps ❶, and ❷ through ❺.

Speciﬁcations

Applications

Motor for grinding (kW)7.5〜

Air flow used (m /min)
Dimensions:
W × D × H (mm)

11〜
2.2〜

Motor for classifying (kW)3Battery materials (positive andnegative electrode materials),

SIGMA DRY ®

Model

2〜4

5.5〜
4〜8

8〜20

20〜50

800 1300 1900 1000 1600 2400 1300 2000 3000 1400 2300 3500

Capability ratio

124

10

Chamber material

Ceramics and metals (only metals in case of SGD125)*The values are representative examples, and the specifications are subject to change without notice.

electronic part materials, ferrites,
various glasses, various ceramics (alumina, silicon nitride, etc.),
carbon, cement, iron and steelslag, ﬂy ash, abrasives, silica,
inorganic substances, food,etc.

Continuous dry bead millfor research & development

Only table-sized modelin industry!

For R&D purposes

Mechanochemical is possibe !
FeatureSmallest size in industry■

Achievement of submicron range with dry grinding■

Maximum particle size of 10 μm without need for classifier■

The 100 times capability of grinding compared to the ball mills■

Testing with minimum sample amount of 0.5 L■

Scaling up to production size

Smallest amount in industry

Grinding data from
Material: Activated carbon
10Activated carbon raw materials

SDA1 processed productFrequency [%]86hes
Reac n rangeoicrsubm

SDA1 processedproduct
Activated carbon
raw materials

d50=0.888μm
d50=6.529μm

4210μm d50=6.53μm dMAX=44μm

1μm

000.1

d50=0.89μm ｄMAX＝9.25μm

0.1110Particle size [μm]100Speciﬁcations
Model
Grinding chamber
volume (L)

1.0

3.8

12.2

2550

125

250

500

Motor (kW)

3.5

5.5

15224575

132

200

W（mm）

400

600

850

1100

1300

2000

2300

2600

D（mm）

600

1300

200025003200

3500

4500

6000

H（mm）

500

1400

1700

2800

3300

1100

1400

1700

50

550

800

1600

2700

5000

7500

12000

Dimensions（W D H）

Weight (kg)
Chamber material
Combability with
1.5mm beads

Ceramics and metals (only metals in case of SDA125 or larger)
○

○

○

­

*The values are representative examples, and the specifications are subject to change without notice.

Comparison data 1

Differences between dry bead mill DRYSTAR® and various grinding machines

Production efﬁciency comparison between dry bead mill DRYSTAR® and dry ball mills
Example of facility comparison between
DRYSTAR® and ball mill

Performance comparison between DRYSTAR® and ball mills
Vibrating ball mill

Rotating ball mill

8020

1Particle size distribution

Sharp

Slightly broad

BroadAchieved particle size

1 to several μm

Several μm

Several μm

Ball size

φ1.5 to 8 mm

φ10 to 20 mm, or Rods

φ20 to 50 mm

Model
Grinding performance

Easy

Diﬃcult

Somewhat diﬃcult

75 to 85 dB (A)85 to 100 dB (A)85 to 100 dB (A)Scaling up
NoiseVibration

Same as general machinery Pollution problems at low frequencies

Somewhat large

Installation areaSmallSomewhat small

Large

Temperature control

Easy

Easy

Diﬃcult

Product collection

Easy

Easy

Diﬃcult

Agitator

Chamber

Chamber

Easy

Diﬃcult

Major undertaking

Continuous passContinuous pass

Batch method

Wear
Maintenance
Grinding method

In cases in which machines are geared for production, it isextremely difficult to manufacture the same product as thetesting sample by using ball mills. In addition, even if it isviable to manufacture a product that is equivalent to thetesting sample, compared to dry bead mill DRYSTAR®, thefacility costs amount to roughly twice as much, three times
more machines are required, the installation area expands
by roughly seven times, and the number of beads needed
increases by roughly 60-fold. Hence, the use of ball mills isinefficient and does not seem to be realistic.

16,000-L
ball mill×3 (Units)（Model: SDA500)

×1 (Unit)

Comparison between dry bead mill and jet millCompared item

Grinding
principle

Grinding media

Grinding force

Surface
grinding

StrongBead diameter, rotating
tip speed, andprocessing ﬂow rate

Bulk grinding

Weak

Classiﬁer and airpressure adjustment

Shear force andimpact force(φ1.5 to 8 mm)of beads
Beads

Jet millAir(Humidity control)

Comparison data 2

Impact ofproduct itself

Particle-size
control

Grinding
configuration

Additional
equipment

Energy costs

Easy...

One-tenthor less relative
to jet mill

Small quantity
neededDiﬃcult...

Extremelylarge

Large quantity
neededDifference between dry bead mill and wet bead mill

Dry bead mills can minimize contamination from beads compared to wet grinding. Therefore, dry grinding is
eﬀective as a pre-grinder for materials that require ﬁne wet-process grinding to a submicron level or nanoscale level.
Dry bead mill
(DRYSTAR®)

Wet bead mill

Bead size

φ1.5 to 8 mm

φ0.015 to 2 mm

Shaft sealing

Easy (Oil seal)

Material wear

LowPrecise(Mechanical seal)(one-tenth of wet grinding)High

Re-agglomeration

Strong

Weak

Particlecompounding
Mechanochemical
effectGood

Possible

Large

Extremely small

Attainable particle size for grinding and dispersing

Raw material

Dry bead millAfter grinding(DRYSTAR®)

After dispersing

Raw material
Wet beadmill0.001（1nm）

After grinding
After dispersing
0.010.1

1101001000 5000（μm）（1mm）

Particle technology for co-creation of new possibilities

Ashizawa Finetech Ltd.
Headquarters, factory,
1-4-2 Akanehama, Narashino-shi, Chiba 275-8572 JAPAN TEL +81-47-453-8111 FAX +81-47-453-8378
and laboratory
Osaka Branch
4-15-13 Katayamacho, Suita-shi, Osaka 564-0082 JAPAN TEL +81-6-6389-7700 FAX +81-6-6389-7710
and laboratory

https://www.ashizawa.com/english/

For website

E-mail sal@ashizawa.com©2020 Ashizawa Finetech Ltd.
2401C5SDA̲SGD（E）-1