The invention relates to a vertical mill comprising a grinding track ( 1 ) and at least one grinding roller ( 2 ). The grinding track ( 1 ) is provided with a central zone (Ia) made of a harder material and two laterally adjacent edge zones (Ib, Ic) made of a softer material. The width (a) of the central zone (Ia) is smaller than or equal to the width of the grinding roller ( 2 ).
1. Vertical mill with a grinding track ( 1 ) and at least one grinding roller ( 2 ), characterised in that the grinding track ( 1 ; 1 ′) comprises a central zone ( 1 a ; 1 ′ a ) of a harder material and two laterally adjacent edge zones ( 1 b , 1 c ; 1 ′ b , 1 ′ c ) of a softer material, wherein the width (a) of the central zone ( 1 a ; 1 ′ a ) is smaller than or equal to the width (b) of the grinding roller ( 2 ).
2. Vertical mill according to claim 1 , characterised in that the laterally adjacent edge zones ( 1 ′ b , 1 ′ c ) of the grinding track are formed by grinding material.
3. Vertical mill according to claim 1 , characterised in that the grinding roller ( 2 ) is of crowned formation.
4. Vertical mill according to claim 1 , characterised in that the grinding roller ( 2 ) is of cylindrical formation.
5. Vertical mill according to claim 1 , characterised in that the grinding roller ( 2 ) is of conical formation.
6. Vertical mill according to claim 1 , characterised in that the width (a) of the grinding track ( 1 ) or of the central zone ( 1 a , 1 ′ a ) is smaller than the width (b) of the grinding roller ( 2 ).
7. Vertical mill according to claim 1 , characterised in that the width (a) of the grinding track ( 1 ) or of the central zone ( 1 a , 1 ′ a ) is between 75% and 95% of the width of the grinding roller.
8. Vertical mill according to claim 1 , characterised in that fittings ( 4 , 5 ) are provided on both sides of the grinding track ( 1 ), these being disposed at a radial distance from the grinding track.
9. Vertical mill according to claim 1 , characterised in that fittings ( 4 , 5 ) are provided on both sides of the grinding track ( 1 ), these being disposed at a radial distance from the grinding track, wherein the interspace which forms is filled with grinding material.
10. Vertical mill according to claim 1 , characterised by a grinding ring ( 3 ), on the surface of which the grinding track ( 1 ) is disposed, which track is delimited on both sides by fittings ( 4 , 5 ), wherein seals ( 7 , 8 ) are provided between the grinding ring and the fittings.