The mechanical aspects of large grinding mills

CIM Bulletin, Vol. 72, No. 811, 1979

C. A. ROLOFF, Senior Application Engineer, Allis-Chalmers Corporation, Mining Systems Division, Milwaukee, Wisconsin

Demands for increased grinding production, lower-grade ore and limited capital have resulted in ever larger grinding mills, some as large as 36ft (11 m) in diameter and 12,000 hp (8,950 kw). The result is often fewer machines per plant, with a greater dependence on each machine. To meet these reliability requirements, manufacturers of mills, drives, castings and other components have had to be innovative and creative in their design. Only by thorough review of past designs and practices and by model studies confirmed in field tests can the manufacturer have full confidence in the product. Because of the great interest in large mills, a short review of larger machines is presented. This discussion covers material feeding, bearings, the rotating element, drive trains and material discharge.

Keywords: Equipment, Maintenance, Milling, Grinding mills, Feeders, Trunnions, Mill heads, Lubrication, Mill shells, Mill drives, Drive trains, Motors, Cascading.