### ballmill for 1 hour - kaplansrestaurant.co.za

Ultrafine Grinding with Laboratory Ball Mills) at 650 min-1 in the PM 100. After 1 hour of size reduction in water with 1 mm grinding balls, the mean value of the particle size distribution is 200 nm; after 4 hours it is 100 nm. In a further trial, the material was initially ground for 1 hour with 1 mm grinding balls and then for 3 hours with 0.1