Method and machine for manufacturing paste, in particular carbon paste for making aluminum production electrodes

1. A method for preparing a paste by mixing or kneading materials, said method comprising the following operations:

a) introducing the materials to be mixed and kneaded into a drum having an inner surface extending along a substantially horizontal axis of revolution;

b) rotating the drum around the axis of revolution and urging the materials via centrifugation against the inner surface of the drum; and

c) locally dislodging, from the inner surface, the materials centrifuged by the rotation of the drum and causing them to fall onto a granulating tool.

2. The method according to claim 1 , wherein,

in operation c) of dislodging, the materials are dislodged using a scraper maintained in a fixed position above the granulating tool, the granulating tool is equipped with blades, and

the granulating tool is made to rotate about a granulation axis of rotation that is substantially parallel to the axis of revolution.

3. The method according to claim 1 , wherein,

in operation c) of dislodging, the materials are dislodged using a scraper maintained in a fixed position above the granulating tool,

the granulating tool is equipped with blades, the granulating tool is made to rotate on a granulation axis of rotation that is substantially parallel to the axis of revolution, said blades being substantially arranged radially to the granulation axis of rotation, so as to come substantially in contact with the inner surface of the drum during the rotation of the granulating tool,

the materials fall between the granulation axis of rotation and the location where the blades come substantially in contact with the inner surface of the drum, and

the granulating tool is rotated in the same direction as the drum.

4. The method according to claim 1 , wherein, in operation b) of rotating, the materials are also compressed mechanically.

5. The method according to claim 1 , wherein in operation b) of rotating, the materials are also compressed mechanically and the materials pass between a roller and the inner surface of the drum.

6. The method according to claim 5 , wherein a liquid binder, including liquid coal-tar pitch, is continuously introduced into the drum, into a lower portion of said drum, followed by a filler, including calcined coke, is introduced onto the coal-tar pitch.

7. The method according to claim 5 , wherein a liquid binder is continuously introduced into the drum, into the lower portion of said drum, followed by a filler is introduced onto the coal-tar pitch.

8. The method according to claim 1 , wherein,

in operation a) of introducing, the materials to be mixed and kneaded are introduced at an upstream end of the drum,

during an operation d), collecting the thoroughly mixed and kneaded materials at a downstream end of the drum, said downstream end being opposite the upstream end in the direction of the axis of revolution, and

the materials are continuously mixed and kneaded, with operations a), b), c) and d) being performed simultaneously, said materials being introduced at the upstream end while previously introduced materials are kept in the drum and other thoroughly mixed materials are collected at the downstream end.

9. The method according to claim 1 , wherein,

in operation a) of introducing, the materials to be mixed and kneaded are introduced at an upstream end of the drum,

in operation b) of rotating, the materials are compressed mechanically and the materials pass between a roller and the inner surface of the drum,

during an operation d) of collecting, the thoroughly mixed and kneaded materials are collected at a downstream end of the drum, said downstream end being opposite the upstream end in the direction of the axis of revolution,

the materials are continuously mixed and kneaded, with operations a), b), c) and d) being performed simultaneously, said materials being introduced at the upstream end while previously introduced materials are kept in the drum and other thoroughly mixed materials are collected at the downstream end, and

wherein the granulating tool extends substantially to the upstream end in the direction of the axis of revolution, but an upstream space is arranged between the upstream end and the roller.

10. The method according to claim 9 , wherein the granulating tool substantially extends to the downstream end in the direction of the axis of revolution, with a downstream space being arranged between the downstream end and the roller.

11. The method according to claim 10 , wherein water is poured onto the materials in said downstream space in order to cool them.

12. The method according to claim 1 , wherein the materials are advanced by the granulating tool towards a downstream end of the drum.

13. The method according to claim 1 , wherein, in operation c), the materials that fall onto the granulating tool are for use for making aluminum production electrodes.