Patent ID: 8047458

Claim:
Method for producing very fine particles by a jet mill comprising the steps of: a) using compressed gases having a pressure of ≦4.5 bar absolute pressure as a grinding gas; b) introducing inorganic substances to be ground by the jet mill; c) maintaining the temperature of the grinding gas above 100 degrees Centigrade; d) initially determining the specific adiabatic energy consumption of the grinding process of the jet mill using a grinding gas pressure of >7 bar absolute pressure; e) thereafter, determining the specific adiabatic energy consumption of the same grinding process of the jet mill using a grinding gas pressure of <4.5 bar absolute pressure; f) comparing the two energy consumptions; and g) in the case where E ad,spec (4.5)≦ E ad,spec (7) continuing the grinding process of the jet mill using the low pressure area.