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Grinding Media

Ceramic Grinding and Milling Media

Radius-End Cylinder and Banded Satellite Sphere Ceramic Grinding and Milling Media

Based Upon Magnesia Stabilized Zirconium Oxide:

Engineered for grinding and milling of zircon, zirconia, barium titanate, food stuffs, pharmaceuticals and electronic ceramics in vibratory, ball, jar and attritor mills. Zircoa grinding media delivers fast grinding and milling, with low contamination and media weight loss.

Our Strategy — Your Satisfaction

Zircoa’s grinding media has been used successfully, for more than 40 years, to grind electronic ceramics, zircon and zirconia. Our on-going engineering and manufacturing refinement allows us to keep pace with this market. This pro-active approach also prepares us for partnering with the newer electronics markets, which demand higher purity and much less contamination.

A Superior Media

Our media is made of magnesia stabilized zirconia. This formulation is non-porous, non-conductive and non-magnetic. It is chemically inert, chip-resistant and extremely hard. Zircoa engineers this formulation into both radius-end cylinder and banded satellite sphere shapes.

Radius-End Cylinders (above) — Developed for use in vibratory, ball and jar mills. Manufactured in various sizes to accommodate your specific requirements. Well-suited for grinding barium titanates and other electronic ceramics, zircon, zirconia and other specialty ceramics.

Banded Satellite Spheres (left) — Developed for use in attritor, ball and jar mills. Measuring 0.25" (6.35mm), this media produces super-fine grinds. It is well-suited for applications such as grinding zircon for opacifiers, zirconia and other applications that demand low contamination.

Specifications

Stocked Sizes of Ceramic Grinding and Milling Media:

Sizes

Approximate Number

of Pieces per

in

(mm)

lb

(kg)

Radius-end cylinders

1.25 x 1.25

(31.8 x 31.8)

3

(7)

1 x 1

(25.4 x 25.4)

7

(15)

0.75 x 0.75

(19.1 x 19.1)

18

(40)

0.5 x 0.5

(12.7 x 12.7)

65

(143)

0.375 x 0.375

(9.53 x 9.53)

150

(333)

0.25 x 0.25

(6.35 x 6.35)

426

(939)

Banded satellite spheres

0.25 D

(6.35 D)

401

(884)

Note: To obtain a 50% media charge, 14 lb. / gal. (1.68kg / l) media are required.

Packing density is approximately 210 lb. / ft.3 (3364kg / m3); 28 lb. / gal. (3.36kg /l).

Physical Properties of Ceramic Grinding and Milling Media:

Properties

Units

Values

Chemistry

ZrO2

wt %

97

MgO

wt %

3

SiO2

wt %

<0.3

CaO

wt %

<0.3

Fe2O3

wt %

<0.2

Al2O3

wt %

<0.2

TiO2

wt%

<0.2

Physical

Bulk density

g/cm3

5.5

Apparent porosity

%

0

MOR at room temp

1000 psi

Mpa

60

414

Tensile strength at room temp (.6 MOR)

1000 psi

Mpa

36

248

Fracture toughness (K1C)

MPaÖm

7

Weibull Modulus

10

Hardness - Rockwell

“A” scale

80-84

- Vickers

HV0.3Kg/mm2

1050


Mill Mates® Plus™ Dispersion and Milling Media

Ceramic Dispersion and Milling Media

Based Upon Ceria (Ce) Stabilized TZP*

Evolution in mill design and production requirements across a range of viscosities and particle sizes demand a superior media. Mill Mates Plus, from Zircoa, are engineered to satisfy these needs.

Formulations up to 50,000 cps and particle sizes less than 1µm are routinely processed and achieved with very low media and mill wear.

*TZP is an acronym for Tetragonal Zirconia Polycrystals, a form of Zirconium Oxide.

Highly Engineered Performance

Mill Mates Plus are based on Tetragonal Zirconia Polycrystals (TZP). The superior micro-structure makes possible a dispersion media with a higher fracture toughness, density and hardness.

Compared to the closest competing product(s), Mill Mates Plus last longer and require fewer re-charges. Using Mill Mates Plus will reduce mill wear and lessen downtime for maintenance, while it speeds processing time.

For a Wide Range of Formulations

Mill Mates Plus' highly engineered microstructure results in a bead that is fracture and wear resistant, extremely round, tough and dense. Mill Mates Plus become highly polished, resulting in very low friction and abrasive qualities.

Mill Mates Plus… the ultimate in Ceria Stabilized TZP technology. The best dispersion value for your most demanding needs.

Features & Benefits of Mill Mates Plus

Features

Benefits

Tetragonal Zirconia

Polycrystal (TZP) ................

Extremely wear resistant, low contamination

Controlled, consistent

microstructure ....................

Predictable media performance, favorable hardness and toughness combination

Excellent roundness

and size distribution control ...

Maximum shear for increased efficiency in horizontal milling

Smooth

surface ..............................

Low mill wear, easily washed between formulations

High

density ..............................

Maximum throughput in recirculation grinding


Applications and Industries Served by Mill Mates Plus

  • Automotive and Industrial Coating;
  • Inks, Dyes and Pigments;
  • Frits, Glazes and Ceramics;
  • Minerals;
  • Magnetic Materials, Coatings and Dielectrics;
  • Foodstuffs, Pharmaceuticals and Cosmetics;

Optimizing Mill Performance, Reducing Wear

Shear - Extensive testing confirms that shear is the predominant dispersion mechanism in fine media milling. Mill Mates Plus’ tight size distribution and extremely uniform size facilitates and intensifies this effect, delivering more shear during processing.

Product Feed Rate - Dense, smooth, and round media, which are uniform in size, allow for increased feed rates. Mill Mates Plus deliver all these features, minimizing the risk of hydraulic packing.

Particle Size Reduction Rate - Mill Mates Plus uniform size distribution, results in superior dispersion (compared to higher-priced media) reducing the time required to achieve a given particle size.

Mill Component Wear Rate - Laboratory and case studies demonstrate that Mill Mates Plus' low friction coefficient (associated with its smooth surface) results in very low wear on the mill, screen and other components.

Property/

Characteristic

Units

Mg-PSZ

Ce-TZP

Mill Mates

Plus

Y-TZP

Bead Wear Rate

(1 hour under

Hydraulic Packing)

%

8.4

0.1

0.04

Impeller Wear Rate

%

0.29

0.01

0.07


Calculating the Correct Amount of Mill Mates Plus

Horizontal Mill Size

(Void Volume)

Mill Mates Plus (1mm)

for 85% Charge

liters

lbs

kgs

15

20

45

100

200

110

148

333

740

1480

50

67

151

336

673


Specifications

Mechanical Properties - Mill Mates Plus

Property

Units

Mill Mates

Plus

Composition

- -

(Ce-TZP)

Density

g/cm3

6.25

Hardness (HV)

GPa

11.3

Fracture

Toughness, K1C

MPa*m1/2

11.0

Elongation

- -

0.96

Crush

Strength

  1. force

200

Wear Rate*

Bead

Impeller

%

%

0.1

0.01

Surface

- -

Smooth, becoming highly

polished with use

Color

- -

Dark Grey

*1 hour under Hydraulic Packing

Nominal Sizes - Mill Mates Plus

Nominal Size*

Range (mm)

Packing Density

kgs/L

lbs/L

.5 mm

.7 mm

1.0 mm

1.5 mm

2.0 mm

.4 - .6 mm

.6 - .85 mm

.85 – 1.18 mm

1.4 – 1.7 mm

1.7 - 2.3 mm

3.777

3.906

3.938

4.028

4.063

8.33

8.61

8.68

8.88

8.96

* Other sizes available upon request.

Typical Properties Comparison - Mill Mates Plus

Media

Density

g/cm3

Primary

Material

Crushing

Strength

lbs/grain

(a)

Mill Mates Plus

6.25

CeO2 - ZrO2

150 – 300

Zirbeads

5.5

MgO - ZrO2

105 - 220

Zircon beads

3.7

ZrO2 - SiO2

105 – 160

Alumina beads

3.5

Al2O3

125 – 220

Glass beads

2.8

SiO2

40 – 70

(a) ASTM D1213-54

Zirbeads™ Super and Super XR

Ceramic Dispersion and Milling Media

Based Upon Zirconium Oxide

Engineered for uniform size and shape, Zirbeads are extremely hard, non-porous, resist chipping and fractures and are exceptionally smooth, delivering the high shear and intense impact today’s heavy-duty continuous mills demand. Zirbeads can disperse and grind pre-mixes up to 50,000 cps, including: inks, automotive and magnetic coatings, more efficiently than Zircon or Alumina beads, with less contamination.

Formulations up to 50,000 cps and particle sizes less than 1µm are routinely processed and achieved with very low media and mill wear.

Today’s mills operate with media occupying up to 90%, or more, of the void volume.

Zirbeads’ higher density allows for a smaller diameter bead, resulting in more beads per charge, and providing more contact points for the product during residence. Using Zirbeads can double the number of beads per unit of weight.

High viscosity and high percent solid formulations, such as automotive coatings and inks, are the ideal pre-mixes for Zirbeads. The characteristically higher mass of Zirbeads provides the greater power (kinetic energy) needed by formulations of this nature. Zirbeads by Zircoa can disperse and grind pre-mixes up to 50,000 cps.

A Unique Material

Zirbeads are made of zirconia... a unique material, and the most dense ceramic media available. Zirbeads are hard, uniform in size and shape, non-porous, and exceptionally smooth. They resist chipping and fractures, extending the life of the media and the mill, and minimizing batch contamination. Chemically inert, Zirbeads are resistant to virtually all acids and alkali, and are non-conductive and non-magnetic.

Zirbeads Selection

Zircoa has developed two Zirbead grades for most pre-mix formulations and mill requirements.

SUPER (1.4 to 3.35 mm) — When you require media with a wider and more economical distribution ... SUPER is the right choice. Historically used in vertical mills, Zirbeads SUPER now has several horizontal mill applications.

SUPER "XR" (.6 to 2.3 mm) — Designed for today’s modern horizontal mills, Zirbeads SUPER "XR”" provides the narrow size distribution needed for inks, automotive and magnetic coatings.

Optimizing Mill Performance with Zirbeads

To achieve optimum performance, Zirbeads contact with the formulation must be maximized. To achieve this, the agitation speed, Zirbead size, and throughput, must be balanced to the viscosity of the formulation. A donut-flow pattern of Zirbeads inside the mill is an indication of proper balance.

Zirbeads are designed for a formulation viscosity no less than 1000 cps, although milling of lower viscosity formulas is possible. As the viscosity drops, the balance between speed and bead size becomes more critical, to avoid excessive wear on the mill and the media itself. If you hear splashing, the viscosity is too low.

Introduce pre-mix that is sufficiently fine and homogeneous, then start the mill. Zirbeads unsupported by pre-mix can cause start-up and wear problems. Make sure the discharge screen is properly matched to the Zirbead size.

Never mix Zirbeads with other media. Zirbeads will grind-up lower density media such as zircon and glass beads, contaminating the product and causing undue wear on the mill.

  1. The wear rate of Zirbeads is one half to one third that of other dispersion media. See "Typical Properties"
  2. A 21% reduction in diameter allows twice as many beads. See "Suggested Charge Weights"

Suggested Media Charge Weights for Zirbeads

Horizontal Mill Size

(Void Volume)

Zirbeads Super XR

for 85%

(1mm) Charge

liters

lbs.

kg

15

102

46

20

136

62

45

305

139

100

677

308

200

1355

616


Specifications

Available Sizes - Zirbeads

Media

Sizes Nom.

(mm)

Range (mm)

Tyler Mesh

Zirbeads

Super

2.4

2.0

1.4 - 3.35

1.4 - 2.36

-6 +12

-8 +12

Zirbeads

Super XR

2.0

1.5

1.3

1

.7

1.7 - 2.3

1.4 - 1.7

1.18 - 1.4

.85 - 1.18

.6 - .85

-8 +10

-10 +12

-12 +14

-14 +20

-20 +28

NOTE: Other sizes available upon request.

Typical Properties Comparison - Zirbeads

Media

Density

g/cm 3

Primary

Material

Crushing

Strength

lb./grain (a)

Wear

Rating (b)

Zirbeads

5.5

ZrO2 (c)

125 to 220

7

Zircon beads

3.7

ZrO2•SiO2

105 to 160

11

Alumina beads

3.5

Al2O3

125 to 220

22

Glass beads

2.8

SiO2

40 to 70

(d)

Ottawa sand

2.8

SiO2

10 to 20

(d)

(a) ASTM D 1213-54

(b) Zircoa Zirbeads wear test No. 59531. Zero = no wear.

(c) Typical composition (wt. %): ZrO2 97, MgO 3, SiO2 <.35, CaO<.5, Fe2O3 <.1, Al2O3 <.2, TiO2 <.1

(d) Specific gravity too low for test conditions