Benchmarking: Yanacocha Single-stage SAG Mill

Benchmarking: SAG Mill Power Draw - Yanacocha

• Burger, B., Vargas, L., Arevalo, H., Vicuna, S., Sidel, J., Valery, W., Jankovic, A., Valle, R. and Nozawa, E., Yanacocha Gold Single Stage SAG Mill Design, Operation, and Optimization, Proceedings of the International Conference on Autogenous Grinding, Semiautogenous Grinding and High Pressure Grinding Roll Technology (SAG 2011) held September 25 – 28, 2011 in Vancouver, B.C., Canada.

Mill geometry given as:

• mill nominal diameter (inside shell): 32 ft
• mill effective grinding length: 32 ft
• liner effective thickness: 7 inches (175 mm), eyeballed from new liner diagram

Not stated in the paper is that the 16.5 MW motor is gearless with DCS indication assumed to be motor output power.

	Shell Power, kW	Mill Speed, RPM (%crit)	Ball charge, %v/v	Filling, %v/v	Feed %solids	Morrell model, kW	Loveday/Barratt, kW	Austin model, kW
First Survey	12,286	8.9 (64.5†)	16.5	17.9	73	11,716 (4.7% low)	14,754 (18% high)	12,712 (3.4% high)
SecondSurvey	13,992	8.7 (63.1†)	19.1	22.9	80	13,298 (5.1% low)	16,100 (14% high)	14,017 (0.2% high)

^† The %critical speed values given in the text do not appear to account for the liner. The RPM values are assumed to be correct and the %critical speed values have been back-calculated.

Simplified Morrell SAG mill model was run, default k=1.26 (motor input basis) used.