Rod Grinding Mill for sale

The grinding device most applicable to the production of aggregate is the rod mill. It may be employed where abrasive rock must be comminuted to sand sized particles. The reduction ratio is typically between 5 : 1 and 20:1 with a maximum particle size in the feed of about 20 mm.

The rod mill comprises a cylindrical shell, lined with replaceable liner plates, which rotates upon a horizontal axis. The mill contains a mass of hardened steel rods up to 100 mm in diameter as media which occupies approximately 40% of the volume. The mill is supported at each end by hollow, cylindrical bearings, the trunnions, and driven by a peripheral ring gear. The feed material enters the mill through one or both of the trunnions and is discharged through ports in the shell, either end-peripheral discharge or centreperipheral discharge if fed through both trunnions. The mill is operated wet in the vast majority of mineral processing plants i.e. a solid to water ratio of about 2:1 on a weight basis. Within the aggregate industry, however, the material may be dry or moist.

The rotation of the mill causes the rod charge to tumble and cascade producing comminution by a combination of compression and impact. The action of the rods is favourable to the production of 'fine' aggregate since the larger particles holding the rods apart are crushed preferentially and a minimum quantity of very finely sized particles is generated by abrasion and attrition. Nevertheless, the rod mill suffers serious disadvantages when compared to fine crushers; notably lower efficiency of energy utilization and the costly replacement of worn rods.