Effect of type and number of grinding balls on physical characteristics of chicken egg shells powder using ball mill

Bio-ceramic powder from chicken egg shells has been made using a planetary ball mill with varied numbers and types of grinding balls and gradual heating. Chicken egg shells powder is used as a precursor for manufacturing Hydroxyapatite (HA) bio-ceramic material. HA is used as a scaffold, bone filler, and metal implant coating. The manufacture of HA powder with a fine size is very well used for making bone grafts. HA, which consists of calcium and phosphate, is the main component of bone. HA sourced from organic materials such as bovine bones, pig bones, fish bones, goat bones, clam shells, egg shells, snail shells, crab shells, and so on. The research was conducted using a ball mill with variations in the number and ball milling. The balls used are agate and stainless steel. Milling will be carried out in two stages in each variation, namely grinding without gradual heating and grinding followed by gradual heating to a temperature of 900°C. Milling was carried out at 200 rpm for 2 hours. Furthermore, the chicken egg shells powder was characterized using a Scanning Electron Microscope (SEM). The results showed that milling using 45 balls effectively reduced powder size. The powder size decreased in the first stage by 175 µm in the second stage to 32 µm. The Stainless Steel grinding ball type is more effective in reducing powder size than the Agate ball type. The difference in powder size between the two types of balls in the first stage was 133 µm and in the second stage was 80 µm.