Process and apparatus for mixing cohesive powders

Apparatus for mixing cohesive finely-divided powders having a particle size less than about 10 μm in order to obtain a homogenous mixture, which apparatus comprises a container that is closed during operation and that has at least two compartments separated by at least one perforated partition, at least one of the compartments being provided with means for mixing powders and forcing powders through the perforated partition, rotation means for rotating the container from one position to a second position through an angle of rotation of 180° and by vibration means for vibrating the container movement in both the vertical and horizontal directions before, during or after rotation whereby in use powder in one compartment is forced through the at least one perforated partition into the at least one other compartment.

A method for mixing two or more cohesive finely divided powders comprising the steps of

• placing two or more cohesive finely divided powders in a device comprising a container that is closed during operation and a perforated partition defining a plurality of chambers within the container;
• and
• forcing the powders through the partition, wherein the powders are forced through the partition by at least one freely movable part dimensioned to move freely in one of said chambers when said container is moved.

A method of mixing at least two cohesive finely divided powders having a particle size less than about 10 μm, which method comprises subjecting the powders to a rotating movement using a container that is closed during operation, the container having at least two compartments separated by at least one perforated partition wherein periodically the rotating movement of the container is stopped, and powder is forced from one compartment through the at least one perforated partition into the at least one other compartment, wherein the container is rotated in a vertical direction through an angle of substantially 180°, and after each such rotation powder is forced through the perforated partition.

A method for mixing two or more cohesive finely divided powders, comprising the steps of

• placing two or more cohesive finely divided powders in a device comprising a container that is closed during operation, a perforated partition defining a plurality of chambers within the container, and a freely moveable part dimensioned to move freely in one of said chambers when said container is moved;
• and
• forcing the powders through the partition by the movement of said freely moveable part within one of said chambers.