Batch grinding studies by a ball mill for hematite ore

Abstract Most of the industrial operations need size reduction in some form or other. Compression, impact, attrition and cutting are the principle reduction. It is now an established fact that size of fineness by some grinding technique accounts for more than half of the total cost. In the present study hematite ore of hardness 5.5–6.5, specific gravity 5.26 has been subjected to grinding tests in a ball mill. The experiments were conducted at three feed sizes (i. e., −10 + 8 mm, −8 + 5.6 mm, −5.6 + 4.7 mm) and three ball sizes (i.e. 1 inch, ½ inch, ¼ inch). As the grinding time increases, specific surface and energy consumption per unit specific surface area also increases. As the specific surface area increases, energy consumption also increases. As the size of the ball increases specific surface area and energy consumption per unit specific surface area are also increased. Similarly, as the size of the ball decreases energy consumption also decreases uniformly for a particularly feed size. Energy consumption of feed decreased with quantity of feed. The new specific surface area generated also decreases with increase in feed quantity. Energy consumption per unit surface area of the feed is decreased with increase in feed quantity.