# Benchmarking: Bond - Cadia

## Contents

## Benchmarking: Bond/Barratt - Cadia

*Dunne, R., Morrell, S., Lane, G., Valery, W. and Hart, S.*, **Design of the 40 foot diameter SAG mill installed at the Cadia gold copper mine**. Proceedings of SAG 2001, pages I-43 to I-58.

*Lane, G., Foggiatto, B. and Bueno, M*, **Power-based comminution calculations using Ausgrind**. Proceedings of Procemin 2013, Chapter 2, paper 2.

Papers describe a survey conducted shortly after start-up.

### Ore characterization

- Monzonite ore type,
- Wi
_{C}= 16.5 (metric) - Wi
_{RM}= 19.0 (metric) - Wi
_{BM}= 17.1 (metric) - A×b = 36
- DWI = 7.5
- density = 2.7 t/m³

- Wi

### SAG mill characteristics

- Diameter inside shell = 12.2 m (40 ft)
- EGL = 6.1 m (20 ft)
- Ball filling = 12% v/v
- Total filling = 25% v/v
- Mill speed = 78% of critical (Lane et al, 2013 appears to have a typo. They claim 72% which actually looks like the BM speed)
- Pulp density = 70% w/w
- SAG feed is primary crushed to F
_{80}= 98 mm

### Ball mill characteristics

- Diameter inside shell = 6.7 m (22 ft)
- EGL = 11.3 m (36.5 ft)
- Ball filling = 30% v/v
- Mill speed = 72% of critical
- Pulp density = 70% w/w
- Ball mill circuit product P
_{80}= 170 µm

### Modelling

### Results

Result for default Optimized Bond/Barratt SABC-A model conditions:

T80, mm | Esag | Epeb | Ebm | Etotal | t/h | |
---|---|---|---|---|---|---|

Predicted | 2.06 | 8.6 | 0.3 | 8.5 | 17.4 | 2000 |

Survey | 1.34 | 8.6 | - | 8 | 16.6 | 2065 |

Difference | 0.72 | 0 | 0.3 | 0.5 | 0.8 | -65 |

Difference | 54% | 0% | - | 6% | 5% | -3% |

### Discussion

- The rod mill work index was determined on an apparatus with a smooth liner. Bond specified that the liners of a Bond rod mill work index apparatus should have wave liners, and the Optimized Bond/Barratt model is calibrated to the wave-liner machines. If one deducts 2 kWh/t from the rod mill work index (allowance for difference in apparatus) and re-runs the calculation, the following results are obtained:
- E
_{SAG}= 8.3 kWh/t (-3% from survey) - E
_{ball}= 8.2 kWh/t (+2% from survey) - E
_{total}= 16.8 kWh/t (+1% from survey)

- E
- Using the Raw Bond/Barratt model predicts E
_{total}= 18.2 kWh/t (+10% from survey). The Optimized Bond/Barratt model works better at modelling this circuit.