Difference between revisions of "Benchmarking: Fimiston Ball Mills"
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* ''Nelson, M; Valery, W; Morrell, S'', '''Performance Characteristics and Optimisation of the Fimiston (KCGM) SAG Mill Circuit''', Page 233 - 248, SAG 1996 Conference, Vancouver, Canada. |
* ''Nelson, M; Valery, W; Morrell, S'', '''Performance Characteristics and Optimisation of the Fimiston (KCGM) SAG Mill Circuit''', Page 233 - 248, SAG 1996 Conference, Vancouver, Canada. |
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** Diameter inside shell = 5.49 m (18 ft) |
** Diameter inside shell = 5.49 m (18 ft) |
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| − | ** Diameter inside liners = 5.35 m (17.5 ft, |
+ | ** Diameter inside liners = 5.35 m (17.5 ft, 70 mm effective liner thickness) |
** Belly length inside liners (EGL) = 7.60 m (25 ft) |
** Belly length inside liners (EGL) = 7.60 m (25 ft) |
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** Centre-line length = 8.76 m |
** Centre-line length = 8.76 m |
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** Top ball size = 80 mm |
** Top ball size = 80 mm |
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| + | ** Ore density 2.93 t/m<sup>3</sup> |
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Table 5 presents results of a single ball mill survey. The survey measured motor input power. Drives are assumed to have an efficiency of 0.96 and gearbox+pinion efficiency of 0.970, so the model shell power draw is converted to motor input power by dividing by 0.9312. The predicted power draw of '''Example''' project circuit number 7 (Fimiston) using sample '''MLE''', based on the KCGM paper published by Campbell, J. et al; 1998 AusIMM Annual Conference. |
Table 5 presents results of a single ball mill survey. The survey measured motor input power. Drives are assumed to have an efficiency of 0.96 and gearbox+pinion efficiency of 0.970, so the model shell power draw is converted to motor input power by dividing by 0.9312. The predicted power draw of '''Example''' project circuit number 7 (Fimiston) using sample '''MLE''', based on the KCGM paper published by Campbell, J. et al; 1998 AusIMM Annual Conference. |
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! Pulp %solids,<br>w/w |
! Pulp %solids,<br>w/w |
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! Morrell SAG Model,<br>kW at input / ''shell'' |
! Morrell SAG Model,<br>kW at input / ''shell'' |
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| − | ! Nordberg Model,<br>kW at input / ''shell'' |
+ | ! Nordberg Model,<br>no density correction<br>kW at input / ''shell'' |
| + | ! Nordberg Model,<br>density correction<br>kW at input / ''shell'' |
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| Survey 1 |
| Survey 1 |
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| '''3,864''' |
| '''3,864''' |
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| − | | <del>66.7</del> 68. |
+ | | <del>66.7</del> 68.4 <sup>†</sup> |
| 38.7 |
| 38.7 |
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| 72.0 |
| 72.0 |
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| − | | '''3, |
+ | | '''3,798''' / ''3,798'' |
| − | | '''3, |
+ | | '''3,619''' / ''3,370'' |
| + | | '''3,894''' / ''3,626'' |
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| − | <sup>†</sup> The appendix of the paper lists the mill speed as 12.5 RPM. The mill is fixed speed, so the %critical speed is only a function of mill effective diameter (as liners wear). Doing the math (neglecting the balls) gives a 68. |
+ | <sup>†</sup> The appendix of the paper lists the mill speed as 12.5 RPM. The mill is fixed speed, so the %critical speed is only a function of mill effective diameter (as liners wear). Doing the math (neglecting the balls) gives a 68.4% critical speed. |
The ball mill belly length can be achieved with a 18 degree head angle and 1.9 m trunnion diameter. |
The ball mill belly length can be achieved with a 18 degree head angle and 1.9 m trunnion diameter. |
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Latest revision as of 19:59, 26 January 2014
Benchmarking: Ball Mill Power Draw - Fimiston
- Nelson, M; Valery, W; Morrell, S, Performance Characteristics and Optimisation of the Fimiston (KCGM) SAG Mill Circuit, Page 233 - 248, SAG 1996 Conference, Vancouver, Canada.
- Diameter inside shell = 5.49 m (18 ft)
- Diameter inside liners = 5.35 m (17.5 ft, 70 mm effective liner thickness)
- Belly length inside liners (EGL) = 7.60 m (25 ft)
- Centre-line length = 8.76 m
- Top ball size = 80 mm
- Ore density 2.93 t/m3
Table 5 presents results of a single ball mill survey. The survey measured motor input power. Drives are assumed to have an efficiency of 0.96 and gearbox+pinion efficiency of 0.970, so the model shell power draw is converted to motor input power by dividing by 0.9312. The predicted power draw of Example project circuit number 7 (Fimiston) using sample MLE, based on the KCGM paper published by Campbell, J. et al; 1998 AusIMM Annual Conference.
| Survey | Survey Power, kW at input |
Mill speed, %critical |
Total load, %v/v |
Pulp %solids, w/w |
Morrell SAG Model, kW at input / shell |
Nordberg Model, no density correction kW at input / shell |
Nordberg Model, density correction kW at input / shell |
|---|---|---|---|---|---|---|---|
| Survey 1 | 3,864 | 38.7 | 72.0 | 3,798 / 3,798 | 3,619 / 3,370 | 3,894 / 3,626 |
† The appendix of the paper lists the mill speed as 12.5 RPM. The mill is fixed speed, so the %critical speed is only a function of mill effective diameter (as liners wear). Doing the math (neglecting the balls) gives a 68.4% critical speed.
The ball mill belly length can be achieved with a 18 degree head angle and 1.9 m trunnion diameter.
