Low-pressure milling process

1. A process for generating fine particles of a material, comprising:

feeding the material to a milling chamber of a jet mill;

generating a milling gas medium with a rotary blower or a radial blower and directing the generated milling gas medium through at least one fluid nozzle into the milling chamber;

impinging the material with the milling gas medium in the milling chamber to obtain a milling product comprising coarse and fine grains;

passing the milling product to a dynamic air classifier;

separating the fine grains from the coarse grains in the dynamic air classifier;

removing the fine grains from the dynamic air classifier and collecting the fine grains; and

returning the coarse grains to the milling chamber;

wherein a pressure of the milling gas medium is less than or equal to 4 bar (abs) and a temperature of the milling gas is less than 100° C.

2. The process according to claim 1 , wherein the jet mill is an oval tube mill or a spiral jet mill.

3. The process according to claim 1 , wherein the jet mill is a fluidized-bed opposed-jet mill or a dense-bed jet mill, integrated with a dynamic air classifier.

4. The process according to claim 3 , wherein the fine grains are passed through a fines outlet chamber of the dynamic air classifier, and a cross-section of the outlet chamber is increasingly wider in a direction of flow.

5. The process according to claim 1 , wherein

in the separation of the coarse and fine grains, the grains are passed through-a classifying rotor or a classifying wheel of the dynamic air classifier having a clearance height that is constant or increases with decreasing radius, so that a surface area of the classifying rotor or wheel is approximately constant.

6. The process according to claim 5 , wherein the dynamic air classifier comprises a classifying rotor or classifying wheel with an immersion tube, which rotates with the classifying rotor or the classifying wheel.

7. The process according to claim 1 , wherein the milling gas medium comprises at least one gas selected from the group consisting of air, argon, helium, nitrogen and other noble gas.

8. The process according to claim 1 , further comprising:

adding a coating agent or doping agent to the milling;

wherein at least a part of a surface of the particles of the material for milling are covered with the coating agent or doping agent.

9. The process according to claim 1 , wherein the temperature of the milling gas is less than or equal to 95° C.

10. The process according to claim 1 wherein the pressure of the milling gas is less than 3 bar.

11. The process according to claim 1 , wherein the milling gas pressure is 0.15 to 0.5 bar and the milling gas temperature is 15 to 80° C.