Effect of grinding time on the particle characteristics of glass powder

Based on laser particle size analysis and activity index test results, the effect of grinding time on particle characteristics of glass powder is systematically investigated with the aid of the Divas-Aliavden grinding kinetic equation, RRB (Rosin-Rammler-Bennet) and Swrebec distribution model, fractal theory and gray correlational analysis in this paper. The results show that the grinding efficiency of glass powder with large particle size tends to decrease with the increase of grinding time, and draws near to zero after 120 min. Both the equivalent particle size and specific surface area (SSA) of glass powder show a good linear relation to logarithm or double logarithm of grinding time. Both RRB and Swrebec function model can adequately describe the particle size distribution (PSD) of glass powder ground for different times, and according to the RRB distribution model, both the characteristic particle size and the distribution index of glass powder show a downward trend with grinding time, which indicates that the grinding process cannot only levigate glass powder, but also widen its PSD. The PSD of glass powder shows obvious fractal features, and its fractal dimension also has an increasing tendency with grinding time. In addition, the activity index of glass powder increases with grinding time. Depending on the gray correlational analysis, the mass fraction of particles ranging 0-3 mu m has a maximum positive effect on its activity index at early age while particles ranging 3-10 mu m contribute most at later stage. As a result, 90 min is chosen as the optimal grinding time for glass powder in consideration of economical and technical benefits. Crown Copyright (C) 2016 Published by Elsevier B.V. All rights reserved.