The Wonder Ceramic Micro-Macro Milling Media

Jyoti Ceramic is the proud manufacturer of Zirconox milling media, exporting 70% of it’s production to 55 countries globaly for over three decades. Zirconox milling media has proved to be the most efficient, cost effective milling media in varied industries.

Zirconox was formulated in early 1990's from micro fine monoclinic zirconia powder stabilized with rare earth Cerium Oxide transformed to tetragonal polycrystals.

Due to its unique features Zirconox has become synonymous with milling beads and today is considered as the wonder ceramic milling beads.

Physical Propertise
Colour Golden brown
Surface Finish Glossy, Satin Smooth
Density 6.20 ±0.05 g/cm3
Bulk Density 3.85 ±0.15 kg/ltr
Porosity Nil
Water absorption Nil
Hardness on Moh’s scale 9
Hardness on Vicker’s scale (Hv5) 1250-1300
Crushing strength (Ø 1.5mm bead) 215 kgf
Bead Sphericity 90% ≥ 0.95
% Cumulative weight loss / HR(wear test conducted with water)
After 24 hrs. 0.0015
After 96 hrs 0.0010
Chemical Propertise
ZrO2 83%
CeO2 17%

Zirconox milling media are :

Non-contaminative Non-toxic Non-radioactive
Non-magnetic Chemically inert Resistant to all acids and alkalis except hydrofluoric acid

Application Of Zirconox Micro Beads

Zirconox micro beads are being used in varied industries for micro fine milling & dispersion of :

Agro chemicals : Fungicides, Herbicides , Pesticides.

Adhesive, Sealants & Glues.

Ceramic : Ceramic Inks, Engobes, Glazes, Frits, Enamels, Pigments.

Cosmetics. Dyestuff : Textile dyes, Textile Inks.

Electronic materials : Lithium Iron Phosphate battery.

Food Stuff.

Inks : Printing inks, Inkjet - Magnetic inks, Tattoo inks.

Minerals : Calcium Carbonate.

Metal : Gold, Silver, Platinum.

Oxides : Titanium Dioxide, Zirconium Oxide.

Paints & Varnishes : Auto & allied paints, Decorative & Marine paints.

Pharmaceuticals. Zirconox beads are also used for shot peening treatment on metal surfaces, metal polishing, contact eye lenses polishing and a host of many other applications.

Versatile Industrial Applications

Benefits of Zirconox Zirconia Ceria stabilized micro beads are as below.

  • Zirconox micro beads have a density of 6.20 g/cm3, bulk density of 3.85 kg/ltr. hardness 9 on Moh's scale, desired particle size of pigment or slurry will be achieved faster, resulting in better material yield in reduced milling time.
  • Zirconox micro beads are the most cost effective for speedy dispersion and micro fine milling of high viscous (15,000-50,000 CPs) hard & soft substances with insignificant contamination from media wear.
  • Zirconox beads are free from pin holes, cracks, bead fused with other bead resulting in reduced downtime, and greater process safety.
  • Zirconox micro beads have a dense, homogeneous internal micro structure. Due to this property beads maintain glossy satin smooth surface finish and do not crack or shatter easily. As the hours of milling progresses, wear rate of Zirconox micro beads reduces further and surface finish of beads appear more glossy.
  • Zirconox micro beads are extremely gentle to expensive mill parts. With usage of Zirconox beads wear of mill parts is extremely low.
  • Zirconox 90% micro beads maintain sphericity ≥ 0.95 with enhanced sphericity & satin smooth surface finish media flow improves and reduces abrasion resulting in Zirconox beads lasting approximately 300-350 times longer than glass beads, 25-30 times more than MgO stabilized beads, 20-30 times more than Zirconium Silicate beads.

Test conducted by


Practical Wear test with Zirconox - milling media (1.7-2.4 mm) In comparison to actually used glass beads.

In reference to the graph

Initially the cost of Zirconox may be higher by about 17 times than the glass beads

In the course of usage of the mill for about 18 month, it is realized that the amount spent on both types of micro media is the same.

At the end of 24 months it is observed that the cost of glass beads is higher by about 40% than Zirconox.


The above trend is mainly due to exorbitantly high wear of glass beads in comparison to Zirconox beads. Figures from the graph indicate that the glass beads wear is about 300 times more than that of Zirconox.


Fraunhofer Institute, Freising, Germany has approved Zirconox micro media for milling of food stuff in accordance with the regulations of the European Community.

National Radiological Protection Board (NRPB), Great Britain has confirmed that the radio activity of Zirconox is within the regulations established by the European Community.

Graphical Representation of Wear Test Results

Media Type % Cumulative weight Loss / Hr
After 24 Hrs. After 96 Hrs.
Zirconia Ce stabilized Zirconox (India) 0.0015 0.0010
Zirconia YTZ stabilized (China) 0.00213 0.00175
Zirconia Ce stabilized (USA) 0.00233 0.00418
Zirconia MgO stabilized (USA) 0.0236 0.0273
Zirconia Ce stabilized (France) 0.00329 0.00309
Glass Beads (China) 0.2724 0.298

Comparative Typical Property and Wear Rate Chart

Characteristics Units Ce stabilized zirconia
Yttria stabilized zirconia
Ce stabilized zirconia Beads
MgO stabilized zirconia Beads
Ce stabilized zirconia
Glass Beads
Colour Shade - Golden Brown White Brown Golden Yellow Black Transparent
Density g/cm3 ≥ 6.20 6.0 6.17 5.73 6.2 2.24
Bulk Density kg/ltr 3.85 ± 0.15 3.81 3.60 3.59 3.81 1.55
Porosity % 0.00 0.00 0.00 0.00 0.00 0.00
Water Absorption % 0.00 0.00 0.00 0.00 0.00 0.00
Hardness on Moh’s scale 9 9 9 8 9 5.5
Hardness on Vicker’s Scale Hv5 1310 1350 1150-1200 900-950 1250 500-550
Average Bead size taken for crushing strength mm Ø 1.496 Ø 1.615 Ø 1.44 Ø 1.55 Ø 1.52 Ø 1.66
Crushing Load Kgf 215.50 233.82 200.00 81.00 159.57 45.00
Sphericity for 90% of the beads - >0.96 0.98 0.90 >0.95 0.96 0.95
% Cumulative Weight Loss Per Hour of Wear Test (Wear Test conducted with Water) After 24 Hrs. 0.0015 0.00213 0.00233 0.0236 0.00329 0.2724
After 96 Hrs. 0.0010 0.00175 0.00418 0.0273 0.00309 0.2982
Surface Condition of Beads observed after 96 Hrs. of Wear Test in water - Glossy Satin smooth surface, free from pin holes & no broken beads Glossy Satin smooth surface, few beads with pin holes & few broken beads observed Satin smooth few beads with pin holes & few broken beads observed Satin smooth surface, few broken beads observed Dull surface finish observed Dull surface finish observed

Guidelines for Using Zirconox Zirconia Ceria stabilized Micro Milling Beads

The density of Zirconox beads is > 6.20 g/cm3 which is about 3 times greater than the glass beads, 1.6 times > than Zirconium Silicate beads and 1.1 times than the MgO PSZ beads.

As Zirconox beads possess higher density as compared to any other ceramic micro milling beads, it can generate considerable heat during milling process, which may affect physical properties of ingredients being milled. Therefore, it is strongly recommended to provide suitable cooling system to the mill chamber, to monitor dissipation of heat generated during the milling process

Due to higher density of Zirconox milling beads, it is strongly recommended

  • In the use of high viscous formulations.
  • To avoid passage of beads in the slurry, ensure that the size of strainer aperture is minimum 2 times smaller than the average size of beads.
  • To avoid fracture, shearing of beads or flattened plate shaped beads, ensure that the gap between walls & bottom of mill vessel to the stator/agitating arm is maintained minimum 3 to 5 times larger than the average bead size.
  • Smaller the media size larger the number of contact points resulting in reduced milling time enhanced productivity and intensity of the pigment colour
  • Before charging the mill with Zirconox beads, it is strongly recommended to check thoroughly the capacity & volume of the bead mill chamber and to assess the quantity of Zirconox beads required for the mill (i.e. 60 to 85% volume of mill x Bulk Density of Zirconox beads = Quantity).

Chemical Resistance Data of Zirconox Micro Beads at
25 0C Test Time 24 Hrs.

Chemical Medium Concentration % Weight Loss per hour
Acetic Acid (CH3COOH) 50% 0.00
Chromic Acid (H2CrO4) 25% 0.00
Formic Acid (CH2O2) 25% 0.00
Hydrochloric Acid (HCI) 18% 0.00
Hydrofluoric Acid (HF) 24% 0.01
Nitric Acid (HNO3) 35% 0.00
Perchloric Acid ( HClO4) 25% 0.00
Phosphoric Acid (H3PO4) 25% 0.00
Sulphuric Acid (H2SO4) 50% 0.00
Saturated Sodium Hydroxide Acid (NaOH) 50% 0.00

With the exception of Hydrofluoric acid Zirconox beads did not lose it’s gloss or colour

Zirconox Beads
Bulk Density

Dia (mm) kg/ltr
Ø 0.40 - 0.70 mm 3.75 ± 0.05 kg/ltr
Ø 0.70 - 1.20 mm 3.75 ± 0.05 kg/ltr
Ø 1.20 - 1.70 mm 3.85 ± 0.05 kg/ltr
Ø 1.70 - 2.40 mm 3.85 ± 0.05 kg/ltr
Ø 2.40 - 2.80 mm 3.95 ± 0.05 kg/ltr
Ø 2.80 - 3.30 mm 3.95 ± 0.05 kg/ltr

Zirconox Beads Are Available in Following Fraction Sizes

Broad Fraction Size
Ø 0.4 - 0.7 mm Ø 0.7 - 1.2 mm
Ø 1.2 - 1.7 mm Ø 1.7 - 2.4 mm
Ø 2.4 - 2.8 mm Ø 2.8 - 3.3 mm

* We also offer custom fraction size beads, if found feasible for production.

Narrow Fraction Size
Ø 0.05 - 0.1 mm Ø 0.1 - 0.2 mm
Ø 0.2 - 0.4 mm Ø 0.4 - 0.6 mm
Ø 0.6 - 0.8 mm Ø 0.8 - 1.0 mm
Ø 1.0 - 1.2 mm Ø 1.2 - 1.4 mm
Ø 1.4 - 1.6 mm Ø 1.4 - 1.7 mm
Ø 1.6 - 2.0 mm Ø 1.7 - 2.0 mm
Ø 2.0 - 2.4 mm Ø 3.5 - 4.0 mm

Calculation of Media load

Type of Media Load Bead Charge
Closed Horizontal 75% - 85% of Volume
Closed Vertical 70% - 80% of Volume
Open Vertical 60% - 70% of Volume
E.g. : Bead mill net volume capacity is 50 ltr. Charging with Ø 1.2- 1.7 mm bead. For vertical closed type mill it works out to = 35 ltr (70% of mill vol.) x 3.85 kg/ltr (Bulk Density of Zirconox beads) that is 135 kg. of Zirconox micro beads charge required for a 50 ltr capacity closed vertical mill.Considering Bead Ø 1.2 - 1.7 mm & bead charge of 75-85% of volume of grinding chamber for closed horizontal mill, 70-80% of volume for closed vertical mill & 60-70% of volume for open vertical mill.

Zirconox Bead Charge Weight Suggested for Different Capacity Mills

Volume of Gridning Chamber (ltr) Qty. of Zirconox Micro Beads (kgs)
Closed Horizontal Mill Closed Vertical Mill Open Vertical Mill
8.0 23 - 26 22 – 25 18 - 22
15.0 43 - 49 40 – 46 35 – 40
30.0 87 - 98 81 - 92 69 – 81
45.0 130 - 147 121 - 139 104 – 121
60.0 173 - 196 162 - 185 139 – 162
115.0 332 - 376 310 - 354 266 - 310
225.0 650 - 736 606 - 693 520 - 606

Details of Bead Mill Used for Conducting the Wear Test

Mill Type Horizontal Lab Bead Mill
Model LME - 1
Mill Capacity 0.61 Ltr
Ceramic Media (Qty.) 2.35 kgs.
Make NETZSCH, Germany
Mill Container Polyurethane
Mill Agitator Speed 3000 RPM
Media (Milled with) (Qty.) Water

High Speed Bead Mill for Wear Test

After milling for 24 & 96 hours at 3000 RPM (10.0 m/s), beads were collected, washed and dried thoroughly, weighed on sensitive electronic balance (Resolution : 100 mg) & the percentage weight loss was calculated as.



P = Percentage Weight Loss

W1 = Initial Weight of Beads

W2 = Final Weight of Beads

The weight loss of Zirconox micro beads was found insignificant as well as caused lowest wear on mill contact parts. The percentage cumulative weight loss of Zirconox beads was observed to be 0.0015% per hour in the 24 hour test. The percentage cumulative weight loss came down to 0.0010% per hour in the 96 hour test.

Zirconox Macro Milling Media

Zirconox macro milling media are manufactured from micro fine Zirconia powder stabilized with rare earth Cerium Oxide, transformed to tetragonal polycrystals. Zirconox macro media have a density of 6.1 g/cm3, are tough sapphire hard and have a glossy, satin smooth surface finish. After Tungsten Carbide, Zirconox macro milling media are considered to have the highest density among the ceramic materials and the lowest in coefficient of friction. Due to its unique features, Zirconox milling media mills hard and soft high viscous substances faster and produces insignificant contamination from its wear.

Zirconox macro milling media are ideal for particle size reduction, dispersion of hard and soft substances in Attritor mills, Jar mills, lab scale and bulk production Ball mills and Vibro Energy Mills.

For Jar mills, satellite type or iso pressed dia 12.5, 15 & 20 mm balls are ideal, for ball mills dia 20 to 30 mm iso pressed balls are recommended. For Vibro energy mills 6, 10, 12.5, 15 mm dia radius corner / radius end cylinders are recommended.

For low and medium speed attritor mills 6, 8 and 10 mm dia satellite type balls are recommended. Smaller the size of milling media, larger the number of contact points, resulting in reduced milling time. Zirconox macro milling media lasts longer due to its dense, homogeneous internal micro structure, higher toughness and micro fine grain size. Zirconox media are very gentle on mill contact parts.

Zirconox Macro Media Are Available in Following Sizes
Type of Zirconox Macro Milling Media Available Sizes (In mm) Shapes
Uniaxial pressed sphere with ridge / band at centre Dia 6, 8, 10, 12.5
Iso pressed sphere with ring at top Dia 16, 21, 26, 31
Radius end Cylinder (REC) Dia 6, 8, 10, 12.5
Radius end Corner Cylinder (RCC) Dia 6, 8, 10, 12.5, 15, 20, 25
Physical Properties
Colour Golden brown
Surface Finish Glossy, Satin Smooth
Density 6.1 ±0.05 g/cm3
Bulk Density 3.95 ±0.05 kg/ltr
Water absorption Nil
Hardness on Moh’s scale 9
Hardness on Vicker’s scale (Hv5) 1100
Flexural strength at Room Temp 5000 kg/cm2
Chemical Properties
ZrO2 83%
CeO2 17%

Zirconox macro milling media are excellent for milling and dispersion of high viscous formulations, wet and dry grinding of hard and soft substances, such as auto and allied paints, printing inks, colors, pigments, chemicals, Calcium Carbonate, minerals, enamels, glazes, frits, graphite, advanced ceramic materials, dielectric and piezoelectric formulations, cosmetics, batteries, pharmaceuticals, food and a host of many other applications requiring contamination free, speedy micro fine milling or dispersion of formulations.

Jar Mills

Satellite type or ISO Pressed dia. 12.5, 15 & 20 mm balls are ideal.

Vibro Mill

Dia. 6, 8, 10, 12.5, 15 mm radius corner / radius end cylinder are recommended.

Attritor Mills

Satellite type dia. 6, 8 and 10 mm balls are recommended.

Ball Mill

Iso Pressed dia. 20 to 30 mm balls are

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