A1. Principle of the method

This method is based on placing alumina ball within the polyurethane jar and test for grinding strength and loss resistance under regular conditions.

A2. Grinding jar

Polyurethane jar with an inner diameter of 200mm and a length of 220mm

A3. Wear-resistant and shockproof test machine

Containing material, grinding jar with capacity of 4kg alumina ball and 4 liter of water at 80 rpm rotation

A4. Preparation

Put about 4kg of alumina ball sample into grinding jar and add 4L of water, grind material at 80 rpm for 2 hours, then take out and dry the sample or standby.

A5. Test procedures

1. Take sample processed according to A4, weigh out(m1) with a balance of sensibility reciprocal of 0.1g.

2. Put the above sample into grinding jar, add water of the same weight, seal it to prevent water leakage, then put it at wear-resistant test machine, make grinding jar operate 80/min for 24 hours, the stop operation.

3. Take the sample out of the grinding jar, wash it with water, dry it and weight out(m2)

4. Measure average diameter of 10 balls.

A6. The results show

Through wear-resistant and shockproof test, if there is no crack or breaking, the wear-resistant and shockproof properties will be regarded as qualified.

EWT-KD(m1-m2)/m1

In the formula: EWT-wear and tear(‰)

K-coefficient of correction, 4.17X10^-4۰ (mm^-1)

D-average diameter of ball, (mm)

m1-total weight of sample before self-grinding, (g)

m2-total weight of sample after self-grinding,(g)