Difference between revisions of "Bibliography: Benchmarking"

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[[Category:Bibliography]]
 
[[Category:Models]]
 
==Bibliography: Benchmarking of models==
 
The following list of references show data useful for benchmarking against the different models.
 
 
==Benchmarking: Circuit Specific Energy Consumption - Bond/Barratt==
 
* ''Magnuson, R.; Hallow, J.; Mosher, J.; Major, K.'', '''The Fort Knox Mill: Design, Commissioning and Operation'''. Proceedings of the SAG 2001 Conference, Vancouver, Canada.
 
 
[[Benchmarking: Bond - Fort Knox|Show details of benchmarking]]
 
 
Checking the July 1999 survey against the Bond/Barratt model for SAB circuit. Using 15% E<sub>ssbm</sub> contingency.
 
 
* Work index for ball milling=13.67 kWh/t (12.4 kWh/st);
 
* Work index for rod milling=12.02 kWh/t (10.9 kWh/st);
 
* assume Work index for crushing=10 kWh/t (similar to pilot plant samples).
 
* Feed F<sub>80</sub> size= 106 mm
 
* Product P<sub>80</sub> size= 178 &micro;m
 
* Measured E<sub>total</sub>= 10.5 kWh/t relative to shell (10.1 kWh/st relative to DCS)
 
* Bond/Barratt model E<sub>total</sub>= 11.95 kWh/t (model 7% high)
 
* Measured Wi<sub>O</sub>= 14.8 kWh/t (13.4 kWh/st)
 
* Bond/Barrat model Wi<sub>O</sub>= 16.6 kWh/t (model 11% high)
 
 
The paper is assume to report power and specific power consumption values relative to the plant DCS. It is assumed that the DCS measurement happens at the motor input leads; the conversion of DCS to shell power for synchronous motors with pinions is 0.960 &times; 0.985 = 0.9456.
 
 
Mill power draw is given in both Tables 4 and 6. It appears that the units in Table 4 are incorrect, and the SAG and ball mill power draw values appear to be kW and not horsepower, as stated. The power draw values from Table 6 are:
 
* SAG mill power draw= 8,910 kW (11,950 hp). Assumed to be DCS indication.
 
** Conditions to match power draw: balls=16% v/v; filling=31% v/v; speed=75% c/s; 6" liner.
 
* Ball mill power draw= 10,330 kW (13,850 hp, sum of two mills). Assumed to be DCS indication.
 
** Conditions to match power draw: filling=29% v/v; speed=74% c/s; 6" liner.
 
* Measured throughput= 1733 t/h (1910 st/h); Bond/Barratt model= 1522 t/h (model 13% low)
 
 
==Benchmarking: SAG 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 = 10.970 m (36 ft)
 
** Diameter inside liners = 10.797 m (35.42 ft, 3.5 inch effective liner thickness)
 
** Belly length inside liners (EGL) = 4.417 m (14.5 ft)
 
** Centre-line length = 6.920 m
 
Table 4 presents results of several SAG surveys at different speed and load conditions. The survey measured motor input power. Drives are assumed to have an efficiency of 0.96 and pinion efficiency of 0.985, so the model shell power draw is converted to motor input power by dividing by 0.9456. 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.
 
 
{| class="wikitable" border="1"
 
|-
 
! Survey
 
! Survey Power,<br>kW at input
 
! Mill speed,<br>%critical
 
! Ball load,<br>%v/v
 
! Total load,<br>%v/v
 
! Pulp %solids,<br>w/w
 
! Morrell SAG Model,<br>kW at input / ''shell''
 
! Loveday/Baratt Model,<br>kW at input / ''shell''
 
|-
 
| Survey 1
 
| '''9,255'''
 
| 72.5
 
| 13
 
| 21.6
 
| 65.9
 
| '''9,268''' / ''8,764''
 
| '''10,372''' / ''9,808''
 
|-
 
| Survey 2
 
| '''10,374'''
 
| 77
 
| 13
 
| 25.2
 
| 63.3
 
| '''10,481''' / ''9,911''
 
| '''11,238''' / ''10,636''
 
|-
 
| Survey 3
 
| '''8,395'''
 
| 75
 
| 15
 
| 16.1
 
| 70
 
| '''9,193''' / ''8,693''
 
| '''10,818''' / ''10,230''
 
|-
 
| Survey 4
 
| '''8,299'''
 
| 78
 
| 11.5
 
| 13.5
 
| 60
 
| '''7,766''' / ''7,344''
 
| '' can't do ''
 
|-
 
| Survey 5
 
| '''10,976'''
 
| 80
 
| 11.5
 
| 22.2
 
| 60
 
| '''9,877''' / ''9,340''
 
| '''10,322''' / ''9,760''
 
|-
 
| Survey 6
 
| '''8,616'''
 
| 74
 
| 11.5
 
| 13.6
 
| 63
 
| '''7,394''' / ''6,992''
 
| '' can't do ''
 
|-
 
| Survey 7
 
| '''11,684'''
 
| 82
 
| 14
 
| 20
 
| 75
 
| '''10,782''' / ''10,195''
 
| '''11,037''' / ''10,437''
 
|-
 
| Survey 8
 
| '''11,610'''
 
| 78
 
| 13
 
| 28.6
 
| 75
 
| '''11,415''' / ''10,794''
 
| '''11,125''' / ''10,520''
 
|-
 
| Survey 9
 
| '''11,571'''
 
| 78
 
| 13
 
| 25.8
 
| 75
 
| '''10,990''' / ''10,392''
 
| '''11,668''' / ''11,033''
 
|-
 
| Survey 10
 
| '''9,408'''
 
| 80
 
| 12
 
| 19
 
| 75
 
| '''9,655''' / ''9,130''
 
| '''10,309''' / ''9,749''
 
|}
 
 
* The overall average difference between the Morrell model motor input predictions and the measurements are -3.4%, and range from -15.3% to +9.1%.
 
*The overall average difference between the Loveday/Barratt model motor input predictions and the measurements are +4.8%, and range from -6.1% to +25.2%.
 
 
The SAG mill belly length reported can be achieved with a 16.5 degree head angle and 2.47 m trunnion diameter.
 
 
==Benchmarking: SAG Mill Power Draw - Cadia==
 
* ''Radziszewski, P.; Valery, W'', '''Cadia SAG Mill Simulated Charge Behaviour''', Annual General Meeting of the Canadian Mineral Processors, Ottawa, 1999.
 
** SAG mill diameter inside liners = 12.024 m (40 ft, 3.3 inch effective liner thickness)
 
** SAG mill effective grinding length = 6.072 m (19.9 ft)
 
** SAG mill centre line length = 9.212 m
 
** Maximum ball size = 125 mm
 
** Ore density = 2.60 kg/L
 
** Ball density given as 7.85 kg/L.
 
** Pulp density not given. Assuming 70% solids by weight.
 
 
Table III gives details of six SAG mill surveys:
 
{| class="wikitable" border="1"
 
|-
 
! Survey
 
! Survey Power,<br>kW at shell
 
! Mill speed,<br>%critical
 
! Ball load,<br>%v/v
 
! Total load,<br>%v/v
 
! Morrell SAG Model,<br>kW at shell
 
! Loveday/Baratt Model,<br>kW at shell
 
|-
 
| Survey 1
 
| 11,189
 
| 79
 
| 0
 
| 28.8
 
| 11,868
 
| 12,126
 
|-
 
| Survey 2
 
| 10,321
 
| 79
 
| 0
 
| 28.5
 
| 11,787
 
| 12,039
 
|-
 
| Survey 3
 
| 10,824
 
| 78
 
| 4
 
| 25
 
| 12,762
 
| 13,390
 
|-
 
| Survey 4
 
| 14,945
 
| 78
 
| 4
 
| 40.7
 
| 15,806
 
| 15,096
 
|-
 
| Survey 5
 
| 17,586
 
| 74
 
| 12
 
| 31.6
 
| 17,351
 
| 18,216
 
|-
 
| Survey 6
 
| 17,963
 
| 78
 
| 12
 
| 26.1
 
| 17,298
 
| 18,505
 
|}
 
 
==Benchmarking: SAG Mill Power Draw - Cadia==
 
* ''Boghey, A.; Svalbonas, V.; Jones, S.M.'', '''Supply, Installation &amp; Commissioning of the World's Largest Grinding Mill''', Annual General Meeting of the Society for Mining, Metallurgy &amp; Exploration (SME), 2000.
 
 
Mill filling level 33% v/v. Ball charge not measured, but expected to be in 12% to 13% v/v range. Ore density not indicated, assuming 2.65 kg/L. Ball density given as 7.85 kg/L.
 
 
Survey conducted during late commissioning, Figure 8 yields:
 
{| class="wikitable" border="1"
 
|-
 
! Survey
 
! Survey Power,<br>kW at shell
 
! Mill speed,<br>RPM
 
! Mill speed,<br>%critical
 
! Morrell SAG Model,<br>kW at shell
 
! Loveday/Barratt Model,<br>kW at shell
 
|-
 
| 23:30
 
| 19,300
 
| 8.99
 
| 73.7
 
| 17,148
 
| 18,233
 
|-
 
| 23:40
 
| 19,450
 
| 9.4
 
| 77.1
 
| 18,042
 
| 19,199
 
|-
 
| 23:50
 
| 19,550
 
| 9.9
 
| 81.2
 
| 19,058
 
| 19,868
 
|}
 
 
==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, 3.0 inch effective liner thickness)
 
** Belly length inside liners (EGL) = 7.60 m (25 ft)
 
** Centre-line length = 8.76 m
 
** Top ball size = 80 mm
 
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.
 
 
{| class="wikitable" border="1"
 
|-
 
! Survey
 
! Survey Power,<br>kW at input
 
! Mill speed,<br>%critical
 
! Total load,<br>%v/v
 
! Pulp %solids,<br>w/w
 
! Morrell SAG Model,<br>kW at input / ''shell''
 
! Nordberg Model,<br>kW at input / ''shell''
 
|-
 
| Survey 1
 
| '''3,864'''
 
| <del>66.7</del> 68.3 <sup>&dagger;</sup>
 
| 38.7
 
| 72.0
 
| '''3,933''' / ''3,776''
 
| '''3,592''' / ''3,345''
 
|}
 
<sup>&dagger;</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 68.3% critical speed.
 
 
The ball mill belly length can be achieved with a 18 degree head angle and 1.9 m trunnion diameter.
 
 
==Historic &amp; Other Interesting Benchmarking==
 
# ''Myers, J.F., Michaelson, S.D., Bond, F.C.'', '''Rod Milling&mdash;Plant and Laboratory Data''', Technical Publication No. 2175, American Institute of Mining and Metallurgical Engineers, 1947. [http://www.onemine.org/search/summary.cfm/Rod-MillingPlant-And-Laboratory-Data?d=655D010DD9E32C42324054B43931E04C552207CAB9653233F0AC73A4C8F07C4928898&fullText=Myers%20Michaelson%20Bond]
 

Latest revision as of 20:51, 17 January 2013