Multiple compartment grinding mills

Claim 1

A SEGMENTAL PLATE FOR COMBINING WITH LIKE MEMBERS TO DEFINE AN ANNULAR WALL WITHIN A CYLINDRICAL SHELL, SAID PLATE HAVING OPPOSITELY FACING SURFACES OF A CONFIGURATION DEFINING AN ARCUATE EDGE SUBTENDED BY A PAIR OF RADIAL EDGES CONVERGING TOWARD EACH OTHER IN THE DIRECTION RADIALLY INWARD OF SAID ARCUATE EDGE, SAID CONFIGURATION OF SAID OPPOSITELY FACING SURFACES ALSO DEFINING IN A FIRST OF SAID RADIAL EDGES A NOTCH HAVING A FLAT WEDGE SURFACE TRANSVERSE THERETO THAT SLOPES FROM SAID FIRST RADIAL EDGE PROGRESSIVELY DEEPER INTO SAID PLATE AT LOCATIONS PROGRESSIVELY MORE REMOTE FROM SAID ARCUATE EDGE, AND A WEDGE LUG PROJECTING FROM THE SECOND OF SAID PAIR OF RADIAL EDGES AND HAVING A FLAT WEDGE SURFACE TRANSVERSE TO SAID OPPOSITELY FACING SURFACES AND SAID SECOND OF SAID RADIAL EDGES, SAID LUG FLAT WEDGE SURFACE HAVING A SLOPE FROM SAID SECOND EDGE PROJECTING FARTHER AWAY THEREFROM AT LOCATIONS PROGRESSIVELY MORE REMOTE FROM SAID ARCUATE EDGE, SAID NOTCH WEDGE SURFACE AND SAID LUG WEDGE SURFACE BEING SPACED AN EQUAL DISTANCE FROM SAID ARCUATE EDGE AND DEFINING EQUAL ANGLES WITH THE RADIAL EDGE CONNECTED THERETO.