Abstract: A sizer tooth assembly for a mineral sizer is described. The tooth assembly includes a horn protrusion extending from a rotatable support, the horn protrusion having a pair of opposed front and rear faces; and a shell structure encapsulating the horn protrusion and defining the outer shape of the sizer tooth; wherein the shell structure comprises exactly two cover formations which are non-releasably secured to one another but not to the horn protrusion, to define when so secured a unitary tooth assembly. Each of the two cover formations seats upon and presents an inward engagement face to a respective one of the pair of opposed front and rear faces of the horn protrusion; and each such engagement face of a cover formation and its corresponding face of the horn protrusion are provided with a complementary arrangement of projections and recesses configured such that when the two cover formations are non-releasably secured to one another the shell structure is releasably connected upon the horn protrusion.

Abstract: A sizer tooth assembly for a mineral sizer is described. The tooth assembly includes a horn protrusion extending from a rotatable support, the horn protrusion having a pair of opposed front and rear faces; and a shell structure encapsulating the horn protrusion and defining the outer shape of the sizer tooth; wherein the shell structure comprises exactly two cover formations which are non-releasably secured to one another but not to the horn protrusion, to define when so secured a unitary tooth assembly. Each of the two cover formations seats upon and presents an inward engagement face to a respective one of the pair of opposed front and rear faces of the horn protrusion; and each such engagement face of a cover formation and its corresponding face of the horn protrusion are provided with a complementary arrangement of projections and recesses configured such that when the two cover formations are non-releasably secured to one another the shell structure is releasably connected upon the horn protrusion.

Abstract: A mineral breaker is described having a breaker unit (1) with at least one rotary drive shaft (15), a rotary electric motor (13), and a drive gear box (17). The breaker unit drive shaft is coupled for rotation to an output shaft of the drive gear box, the rotary electric motor is coupled to rotatably drive an input shaft of the main drive gear box. The rotary electric motor is a switched reluctance motor.