Research on Superfine Grinding Process and Kinetics of Calcined Black Talc in Planetary Mill

This work investigated the size reduction process of calcined black talc using a high energy CJXXM planetary mill. The grinding effects of two different grinding media, aluminia and zirconia, and three kinds of grinding aids, ethanol triethanolamine and sodium hexametaphosphate on the average particle size D50 was compared. The specific surface area, morphology and crystal structure of the ground calcined black talc was characterized by BET, SEM and XRD. The kinetic models of the -1 μm particles in the product are also been studied. The result shows that the zirconia is superior to aluminia as grinding media, and ethanol is a better grinding aid for calcined black talc compared with triethanolamine and sodium hexametaphosphate. The D50 of product can be 1.09 μm within 15 min. No agglomerations between fine particles are formed in the product. The (220) is the most unstable crystal plane. Kinetic models of calcined black talc in a planetary mill under dry superfine grinding conditions using zirconia as grinding media with and without ethanol can be expressed as and respectively.