JC/T 848.1-2010Alumina grinding ball (English PDF)

3.1 Pressing model ball

Alumina grinding ball that is formed by cold isostatic pressing.

3.2 Rolling ball

Alumina grinding ball that is formed by rolling.

3.3 Hat edge

The forming marks on the surface of the alumina grinding ball during cold isostatic pressing.

3.4 Radial size

The maximum diameter of the ball measured parallel to the ball cap of the pressing model ball.

3.5 Latitudinal size

The maximum diameter of the ball measured perpendicular to the ball cap of the pressing model ball.

3.6 Ball degree

The ratio of the difference between the radial size and the latitudinal size of the pressing model ball to the specification size.

3.7 Wear and tear

The mass loss of alumina grinding ball after grinding with water in a polyurethane tank for a certain period of time.

4.1 Classification

Alumina grinding ball is classified according to the following method.

4.1.1 It can be classified into pressing model ball and rolling ball according to the forming method.

4.1.2 The alumina content is classified into 70 series, 90 series, 92 series, 95 series, 99 series;

it can also generate other series as per the agreement.

4.1.3 It can be classified into large ball phi >= 20mm and small ball phi < 20mm according to the specification size.

4.2 Specification

The common specification of the alumina grinding ball is as follows:

4.2.1 Pressing model ball: phi 20mm, phi 25mm, phi 30mm, phi 35mm, phi 40mm, phi 45mm, phi 50mm, phi

60mm, phi 70mm, phi 80mm; it can also generate other specifications as per the agreement.

4.2.2 Rolling ball: phi 2mm, phi 6mm, phi 8mm, phi 10mm, phi 13mm, phi 20mm, phi 25mm, phi 30mm, phi

40mm, phi 50mm, phi 60mm; it can also generate other specifications as per the agreement.

5.1 Apparent quality

The apparent quality of the alumina grinding ball shall comply with the provisions of Table 1.

5.2 Apparent size and deviation

5.2.1 The apparent size and deviation of pressing model ball shall conform to the provisions of

Table 2.

5.2.2 The apparent size and deviation of rolling ball shall conform to the provisions of Table 3.

Table 3 - Apparent size and deviation of rolling ball Unit: mm

5.2.3 The ball degree requirements for pressing model ball shall comply with the provisions of

Table 4.

6.1 Appearance quality inspection

For appearance quality inspection, randomly select 10 balls from a 25 kg of sample and inspect them using a vernier caliper with an accuracy of 0.02 mm.

6.2 Appearance size and deviation inspection

For appearance size inspection, take 10 balls that have passed the appearance quality inspection and measure them using a vernier caliper with an accuracy of 0.02 mm. For rolling balls, measure their diameters in two perpendicular directions. For pressing model balls, measure their radial size and latitudinal size; and take the arithmetic mean of the diameters. The appearance size and deviation shall comply with the provisions of Tables 2 and 3.

6.3 Ball degree inspection

10 pressing model balls that have passed the appearance quality inspection and size deviation inspection shall be measured using a vernier caliper with an accuracy of 0.02 mm. Each ball shall measure its radial size and latitudinal size, as well as the ratio of the difference between the radial and latitudinal sizes to the specification size.

6.4 Determination of water absorption

Take balls that have passed the appearance quality inspection, size deviation inspection, and ball degree inspection. Take 3 large balls or 3 groups of large balls (each group weighing approximately 100 g); and 3 groups of small balls (each group weighing approximately 100 g).

Test water absorption according to the test methods specified in Clause 5 of GB/T 8488-2001.

6.5 Determination of bulk density

Take balls that have passed the appearance quality inspection, size deviation inspection, and ball degree inspection. Take 3 large balls or 3 groups of large balls (each group weighing approximately 100 g), and 3 groups of small balls (each group weighing approximately 100 g).

Test bulk density according to the method specified in GB/T 2997-2000.

6.6 Determination of alumina content

Conduct the test in accordance with Clause 9, “Determination of Alumina”, of GB/T 6900-2006

6.7 Determination of ferric oxide content

Conduct the test in accordance with Clause 10, “Determination of Iron Oxide”, of GB/T 6900-

2006.