View source for Benchmarking: Bond - Cadia East

[[category:benchmarking]]
[[category:Bond/Barratt Model]]
==Benchmarking: Bond/Barratt - Cadia==
''Engelhardt, D., Robertson, J., Lane, G., Powwel, M.S. and Griffin, P.'', '''Cadia Expansion - From open pit to block cave and beyond'''.  Proceedings of MetSoc 2012.

Design criteria and plant trial of underground Cadia East ore


===Ore characterization===
* blased underground ore, secondary crushed to 80 mm.
** Wi<sub>C</sub> = 30 (metric) 
** Wi<sub>RM</sub> = 26.5 (metric)
** Wi<sub>BM</sub> = 21.4 (metric)
** DWI = 9.9
** density = 2.7 t/m³

===Modelling===

Details of the mill operating conditions are not given, but the power draw at the shell is given.  
* 15.737 MW SAG mill power draw
* 19.509 MW ball mill power draw

Circuit operating conditions:
* F<sub>80</sub> = 80 mm
* P<sub>80</sub> = 140 &micro;m
* instantaneous throughput = 1482 t/h

The mill load, ball charge and pulp density was tweaked to mimic these power draws, corresponding to:
* SAG operating 9% v/v balls, 25.5% v/v total filling and 78% of critical speed (Austin model has fixed %solids)
* ball mills operating 37% v/v total filling and 70% w/w solids (fixed speed mills, 72% speed)

The ball load required to match the reported power draw is very high, and could only be achieved with a significant reduction in the trunnion diameter (using ball retaining rings).  Moreover, the motors are predicted to be operating at 100.5% of their rated output power to achive the indicated power draw; drawing full power.

===Model results===
{| class="wikitable" border="1"
|-
!
! E<sub>SAG</sub> 
! E<sub>ball</sub>
! E<sub>total</sub>
|-
| Model
| 12.2 kWh/t
| 15.1 kWh/t
| 27.7 kWh/t
| 1294 t/h
|-
| Measured
| 10.6 kWh/t
| 13.2 kWh/t
| 23.8 kWh/t
| 1482 t/h
|-
| Difference
| 1.6 kWh/t
| 1.9 kWh/t
| 3.9 kWh/t
| -188 t/h
|-
| Difference
| 15%
| 14%
| 16%
| -13%
|}