The invention discloses a preparation method of an
alumina milling balll. The preparation method comprises the following steps: 1) sieving aluminum
oxide powder with the purity of more than or equal to 99.995%, the particle size D50 value of 0.6-1.0 [mu]m and the specific surface area of less than or equal to 8 m<2> / g to obtain sieved aluminum
oxide powder; 2) collecting the sieved
alumina powder,adding pure water accounting for 5-20% of the weight of the sieved
alumina powder, and preparing ball seeds in a ball forming
machine, when the particle size of the ball seeds reaches 0.1-0.3 mm, adding sieved aluminum
oxide powder on the ball seeds in the ball forming
machine to start to grow balls, when the
ball diameter is increased to 0.5-0.6 mm, adjusting the rolling moving track of the ball, and adding sieved alumina powder to continuously grow the ball, when the
ball diameter is increased to 0.7-0.8 mm, adjusting the rolling moving track of the ball, and adding sieved aluminum oxide powder to grow the ball continuosuly, when the
ball diameter is increased to 0.8-0.9 mm and the
apparent density of the alumina ball after ball repairing and pressing reaches 1.5 g / cm<3> or above,
drying and
sintering the balls at 1300-1400 DEG C for 15-25 hours to obtain the alumina milling ball. The alumina milling ball has the characteristics of high purity, low abrasion, high strength and smoothand round surface.