Cold grinding method for making powders

摘要

The particled starting material is cold ground in the mill (20) and supplied through a connecting pipe (24) to a sifter (26). From the sifter, the powder can be removed through a fine material outlet on one side whilst the cool coarse ground material is returned to the mill (20) through a return pipe (46) on the other side. The material is conveyed through a fluid conveyor using a propellant gas such as an inert gas. The temperature in the mill, pipes and sifter is kept below -50 deg C. The ground material is sucked or blown into the sifter which can break down material balls