A Study of Pulverization of Limestone by the Tower Mill (Type KD-1)

Abstract

In Japan, limestone is one of the self-sufficient mineral resources, but is used mostly as a raw material for cement production. Other more valuable use for this resource must be found. We thought pulverization of limestone was the most important subject, so we pulverized it by the Tower Mill (Type KD-1) in dry semi-continuous systems, and examined factors affecting the weights or the particle diameters of the pulverized products. In every experiment, we made the weight of steel balls in the pulverizer and the number of revolutions of the screw constant, and varied the weights of limestone and the air flow rates (U_m) in the tower. We found that decreasing the value of U_m decreased the weight and the particle diameter of the pulverized product. We also found that the maximum value of the particle diameter (D_max) of the pulverized product was dependent on the value of U_m. We obtained the minimum value of D_max, 16μm, when the weight of limestone was 1.0kg and the value of U_m was 0.10m/s.