COMMINUTION KINETICS OF CEMENT IN TOBU MILLING

By employing operational data, the applicability of the following comminution kinetics equation to closed-circuit grinding for cement was investigated. R(D-p, t)/R(D-p, O) = exp (- ktD(p)(n)) It is revealed that k and n vary with the progress of comminution, though these values are formerly regarded as constants. The value of n is affected by the grain size, and the value of it varies with n. And this relation is expressed by the following equation. k = 5.93 x 10(-4) x (22.5 x 10(-6))(-n) When the equation is substituted for the comminution kinetics equation, n is the only parameter for change of the size distribution by grinding. R(D-p, t)/R(D-p, O) is a constant value at D-p = 22.5 x 10(-6)m for the same grinding time: there is a fixed point P-5,(D-p, R(D-p, t)/R(D-p, O)) which satisfies for all k and n. Moreover, some compensation for k is needed, but it is less than 4 mu m.