Tungsten carbide balls are a high-end choice among ball mill grinding media, primarily composed of sintered tungsten carbide (WC) and cobalt (Co) binders. They possess extremely high hardness, reaching HRA 88–93, and a density of approximately 14.5–15.0 g/cm3, far exceeding that of ordinary steel balls. This high hardness is attributed to the fine, uniform WC grains firmly embedded within the cobalt matrix, forming a tough and wear-resistant composite structure, whose wear resistance is several times that of high-chromium steel balls.
Tungsten carbide balls exhibit excellent comprehensive performance. Firstly, they possess superior wear resistance, showing minimal wear even in high-intensity grinding environments, significantly extending their service life. Secondly, they have good impact resistance; the appropriate cobalt content provides sufficient toughness, preventing breakage during high-speed impacts. Furthermore, it is chemically stable and does not readily react with acids, alkalis, or oxidizing slurries, making it particularly suitable for processes with stringent purity requirements. Finally, precision machining ensures extremely high sphericity and a smooth surface, resulting in a uniform and stable grinding process and avoiding localized over-grinding or dead zones.
In practical selection, the diameter range is typically 0.5–50 mm, with 3–20 mm being the most commonly used. Smaller diameter balls are preferred for fine grinding aiming for submicron-level particle sizes to increase the number of contact points; larger diameter balls are used in coarse grinding or crushing stages to increase the single-impact energy. It is recommended that the filling rate be 30–40% of the total volume, with a ball-to-material mass ratio controlled between 1.5:1 and 3:1 to achieve optimal grinding efficiency.
Tungsten carbide balls are widely used in many high-precision fields. In mineral processing, they can efficiently grind quartz sand to extremely fine particles, with a long media life and low maintenance costs. In the ceramics industry, they are used for dispersing slurries such as zirconium oxide and alumina, avoiding iron contamination and ensuring the finished product has pure color and excellent performance. In the preparation of lithium-ion battery cathode materials, ball milling of precursors such as lithium iron phosphate can achieve a narrow particle size distribution and improve the electrochemical cycling stability of the material.
Although the unit price is higher than that of steel balls, the overall operating cost is significantly reduced when considering replacement frequency, downtime losses, and pollution risks. To fully utilize its advantages, the ball mill speed should be controlled below 75% of the critical speed to prevent the balls from centrifugally adhering to the mill wall and losing their grinding effect.
