Apparatus (10) for supplying a material to be formed (8), such as powder and/or slip, to a plant for producing slabs (88), comprising means (12) for supplying the material to be formed (8), first collecting and moving 5 means (14), a conveyor cassette (16) and second collecting and moving means (18), wherein:
- the means (12) for supplying the material to be formed are adapted to take the material to be formed (8) from reservoirs (28) and deposit it in a controlled manner on the first collecting and moving means (14) so as to form a semi-finished mat (80) of material to be formed (8);
- the first collecting and moving means (14) are adapted to provide a stable base for collecting the material to be formed (8) deposited by the supplying means (12) and to move the semi-finished mat (80) of material to be formed (8) towards the conveyor cassette (16);
- the conveyor cassette (16) is adapted to receive the semi-finished mat (80) of material to be formed (8) from the first collecting and moving means (14), and it is adapted to deposit a uniform pad (82) of material to be formed (8) on the second collecting and moving means (18);
- the second collecting and moving means (18) are adapted to provide a stable base for collecting the uniform pad (82) deposited by the conveyor cassette (16) and to move the uniform pad (82) towards successive stations in the plant;
- characterized in that the conveyor cassette (16) comprises at least one flap (20) adapted to cross the entire thickness of the flow of material to be formed (8) which, in use, goes through the conveyor cassette (16).