20mm Grinding Ball, Sintered Corundum

20mm Grinding Ball, Sintered Corundum (Aluminum Oxide)

Product Overview This 20mm grinding ball is made from sintered corundum (Al₂O₃), also known as aluminum oxide, a high-purity ceramic material renowned for its exceptional hardness, wear resistance, and high density. These balls are designed for use in planetary ball mills, where they are placed inside grinding bowls along with the sample material to achieve size reduction, mixing, or homogenization.

How Grinding Balls Work In a planetary mill, the centrifugal forces generated by the rotating bowls cause the grinding balls to collide with the sample material at high energy. This process effectively grinds the sample down to a fine powder. The final particle size of the sample is influenced by several factors:

• Ball Size: Larger balls provide higher impact energy, resulting in coarser grinding. Smaller balls, like this 20mm option, offer more grinding points and produce a finer final product.
• Ball Quantity: Increasing the number of balls generally reduces grinding time and leads to a finer particle size distribution, up to an optimal loading point.
• Material: The material of the grinding media should be harder than the sample being processed to prevent excessive wear and contamination.

Usage and Application Guidelines

• Recommended Use: Sintered corundum balls are ideal for processing medium-hard, brittle, and fibrous samples. They are widely used in materials science, ceramics, geology, and chemical analysis.
• Loading Volume: For effective grinding, it is crucial not to overfill the grinding bowl. As a rule of thumb, the grinding balls and sample material should not occupy more than two-thirds of the bowl's volume, leaving at least one-third of the space empty to allow for free movement and impact.
• Material Compatibility: It is best practice to use grinding balls and bowls made of the same material to avoid cross-contamination. Sintered corundum balls are designed to be used with Sintered Corundum Grinding Bowls. For extremely hard samples, using harder media like tungsten carbide balls in steel bowls or zirconium oxide balls in corundum bowls can improve efficiency, but be mindful of potential sample contamination.

Key Specifications:

• Diameter: 20mm
• Material: Sintered Corundum (Al₂O₃)
• Density: 3.8 g/cm³
• Hardness: High hardness, resistant to abrasion
• Chemical Properties: Chemically inert, minimal contamination for most applications

Compatible Grinding Bowl Sizes:

• 500ml
• 250ml
• 80mL

Ordering Information:

• Grinding balls with a diameter of 20mm are sold individually.
• Classic Grinding Bowls and Premium Grinding Bowls are sold separately.
• Note: Balls with a diameter of 3mm and smaller are sold in packs of 100.