Widely used in ball mills for ceramics, minerals, pigments and chemicals, the alumina grinding balls are the hero, but what affects their performance? The alumina content in the alumina grinding balls is the most critical factor which can affect the performance, mainly when it ranges from 75 per cent to 95 per cent. The real difference is within the formation, where if the alumina content is higher, it means hardness and better wear resistance, but there are more nuances that need attention first.
From powdered potential to mighty milling warriors
Alumina balls are usually made from high-quality alumina powders, likely calcined α-alumina or the refined industrial alumina. The alumina content, which typically ranges from 65 per cent to over 99 per cent, increases along with its purity and performance. The higher-purity alumina balls usually offer better wear resistance and less contamination, and are highly known for their impressive hardness.
This hardness boasts a Mohs hardness of 9 and can resist both acidic and alkaline corrosion. Its features are able to withstand temperatures above 1000 °C and maintain their structural integrity under pressure. Its bulk density is typically between 3.6 and 3.8 g/cm³, facilitating efficient energy transfer during grinding. Wet milling tests reflect wear rates as low as 0.01 per cent, while dry milling conditions demand even greater strength and wear resistance.
