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1. Typical characteristic of wear-resisting alumina ball
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项目 Item |
92% Al2O3 |
75%Al2o3 |
65%Al2O3 |
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Al2O3 (%) |
92 |
75 |
65 |
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Bulk Density(g/cm3) |
3.06 |
3.26 |
2.90 |
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Water Absorption (%) |
<0.01 |
0 |
<0.01 |
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Wear Loss (%) |
≤0.2 |
≤0.25 |
≤0.5 |
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Hardness(MOhs) |
9 |
8 |
7~8 |
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Color |
White |
White |
Light Yellow |
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Application |
Glaze Milling Tile body Milling |
Glaze Milling |
Glaze or Tile body Milling |
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Raw Materials |
Calcined Alumina Powder |
Calcined Alumina Powder |
Refined Bauxite Powder |
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Forming method |
CIP |
CIP |
CIP |
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Diameter(mm) |
0.5~70 |
10. 20. 30. 40. 50. 60. 70 |
Note: 1) Wear loss is tested according to the Chinese National Standard JC/T848.1-1999.
2) Above technical data is typical test result, the real value may change within acceptable tolerance.
2. TEST METHOD OF ALUMINA BALL
＊ Principle of Method
This method means that alumina ball is impacted and in specified condition in polyurethane jar to test the sock resistance, taking abrasion consumption unit time as wearable performance of alumina ball.
Grinding Jar
The grinding jar is made of polyurethane with inner diameter of 200mm, length of 220mm and volume of 27.6 liters.
Anti-wearing and Anti-impacting test machine
It can guarantee the grinding jar with 4kg alumina balls and 4 liters of running water inside continuously runs at 80 rpm.
Specimen Preparation
Alumina ball sample with qualified appearance and dimension is about 4kg. the sample and 4 liters running water put into the grinding jar and ground on anti-wearing and anti-impacting test machine at 80 rpm for 2 hours then taken out, cleaned with water and dried for preparation.
Testing Step
1. m1 of Samples after treatment is weighed with balance with resolution of 1g.
2. The above samples and water of same weight are put into grinding jar without water leaking out, the rubbing jar is put on anti-wearing and anti-impacting test machine at 80 rpm for 24 hours and then shut down.
3. Take samples out of from the jar, clean them with water, dry and weigh them as m2.
Measure average diameter of alumina balls.
3. Dosage calculation of alumina balls
During wet grinding process, when chare dosage of alumina balls is up to 50% of net volume of ball mill, the best status can be realized , and the weight of ball body within ball mill can be estimated with formula:
G= 3.14 * r2 *d*L*25%÷1000
G: charge weight of alumina balls (kg) r: radius of cylinder (cm) d: stacking proportion of alumina balls (g/cm3) L: net length of cylinder (cm)
In order t improve the grinding ability, the above formula would be changed simultaneously due to the difference of grinding aids. Wet ball mill smashes materials mainly through grinding instead of impacting. So , the initial ball charge proportion is advised as large size ball 20%, middle size ball 30% and small size ball 50%, which can get good grinding effect. In practice, the proportion must be adjusted according to the granularity of raw materials, diameter and rotary speed of ball mill, to ensure the best grinding effect and granularity.
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