Grinding Media Material
The grinding media in a ball mill must be extremely resistant to wear and impact. Grinding media must be made of a hard, wear-resistant material that is not easily cracked. Burrs and cracks on the surface of grinding media are not permitted, and the out of roundness of the steel ball shall not exceed 2% of its diameter.
In recent years, the following grinding media materials have been used in cement ball mills:
1. High Chromium Cast Iron
High chromium cast iron is a white cast iron alloy with high chromium content. It is tough and has good wear resistance, heat resistance, and corrosion resistance. A high chromium cast iron ball has 8-12 times the wear resistance of a common carbon steel ball.
2. Low Chromium Cast Iron
Low chromium cast iron contains a trace of chromium, allowing white cast iron to achieve martensite metallography. Low chromium cast iron has slightly lower toughness than high chromium cast iron, but it has good wear resistance. It can be used to make small balls, short cylinders, and lining plates in a fine-grinding bin.
3. Forged Bearing Steel
Steel balls of various diameters can be made from forged-bearing steel. It has a carbon content of about 1.0%, a chromium content of about 1.5%, and other standard elements. In practice, the loss efficiency of forged-bearing steel balls is greater than that of high chromium cast iron balls. Despite this, it has a large market due to its low alloy element content.
