Benchmarking: Bond - Fort Knox - Revision history

Alex Doll: /* Default Model Results */

2014-09-09T18:53:38Z

Default Model Results

Alex Doll: /* Benchmarking: Bond/Barratt - Fort Knox */

2014-06-17T19:13:23Z

Benchmarking: Bond/Barratt - Fort Knox

Alex Doll: /* Circuit Description and Inputs */

2014-04-21T19:14:18Z

Circuit Description and Inputs

Alex Doll: /* Model Tuning */

2014-04-21T19:10:54Z

Model Tuning

Alex Doll: /* Circuit Description and Inputs */

2013-12-12T16:57:23Z

Circuit Description and Inputs

Alex Doll at 18:55, 1 January 2013

2013-01-01T18:55:30Z

Alex Doll: /* Benchmarking: Bond/Barratt - Fort Knox */

2012-11-17T20:18:06Z

Benchmarking: Bond/Barratt - Fort Knox

Alex Doll: /* Benchmarking: Bond/Barratt - Fort Knox */

2012-11-17T20:14:51Z

Benchmarking: Bond/Barratt - Fort Knox

Alex Doll: Created page with "==Benchmarking: Bond/Barratt - Fort Knox== * ''Magnuson, R.; Hallow, J.; Mosher, J.; Major, K.'', '''The Fort Knox Mill: Design, Commissioning and Operation'''. Proceedings of..."

2012-11-17T19:22:26Z

Created page with "==Benchmarking: Bond/Barratt - Fort Knox== * ''Magnuson, R.; Hallow, J.; Mosher, J.; Major, K.'', '''The Fort Knox Mill: Design, Commissioning and Operation'''. Proceedings of..."

New page

==Benchmarking: Bond/Barratt - Fort Knox==
* ''Magnuson, R.; Hallow, J.; Mosher, J.; Major, K.'', '''The Fort Knox Mill: Design, Commissioning and Operation'''. Proceedings of the SAG 2001 Conference, Vancouver, Canada.

Checking the July 1999 survey against the Bond/Barratt model for SAB circuit. Using 15% Essbm contingency.

The paper is believed 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 × 0.985 = 0.9456.

* 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 F80 size= 106 mm
* Product P80 size= 178 µm
* Measured Etotal= ''10.5 kWh/t'' relative to shell (10.1 kWh/st relative to DCS)
** Bond/Barratt model ''Etotal= 11.95 kWh/t'' (model 7% high)
* Measured WiO= ''14.8 kWh/t'' (13.4 kWh/st)
** Bond/Barrat model WiO= ''16.6 kWh/t'' (model 11% high)

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)

Result for default model conditions:
{| class="wikitable" border="1"
|-
!
! Etotal
! WiO
!
! Tonnage
!
|-
| Model
| 11.95
| 16.60
| kWh/t
| 1,522
| t/h
|-
| Measured
| 10.50
| 13.97
| kWh/t
| 1,733
| t/h
|-
| Difference
| 1.45
| 2.63
| kWh/t
| 211
| t/h
|-
| Difference
| 12.9%
| 17.2%
|
| 12.9%
|
|}

@@ Line 39: / Line 39: @@
 ===Default Model Results===
 [[file:BenchmarkingModel-FortKnox.png|thumb|alt=Screenshot showing model output screen|Model screenshot]]
-* Using 15% E<sub>ssbm</sub> contingency (default for SAB circuit).
+* Using 10% E<sub>ssbm</sub> contingency (default for SABC circuit).
-* Bond/Barratt model ''E<sub>total</sub>= 11.95 kWh/t'' (model 13% high)
+* Bond/Barratt model ''E<sub>total</sub>= 11.43 kWh/t'' (model 9% high)
-* Bond/Barrat model Wi<sub>O</sub>= ''16.6 kWh/t'' (model 13% high)
+* Bond/Barrat model Wi<sub>O</sub>= ''15.9 kWh/t'' (model 9% high)
-* Bond/Barratt model throughput= ''1513 t/h'' (model 13% low)
+* Bond/Barratt model throughput= ''1607 t/h'' (model 7% low)
 Result for default model conditions:
@@ Line 55: / Line 55: @@
 |-
 | Model
-| 11.95
+| 11.43
-| 16.62
+| 15.90
 | kWh/t
-| 1,513
+| 1,607
 | t/h
 |-
@@ Line 69: / Line 69: @@
 |-
 | Difference
-| 1.45
+| 0.93
-| 2.01
+| 1.29
 | kWh/t
-| 220
+| 126
 | t/h
 |-
 | Difference
-| 12.9%
+| 8.9%
-| 13.8%
+| 8.8%
+|
-| 12.7%
+| 7.3%
+|
 |}

@@ Line 6: / Line 6: @@
 Checking the July 1999 survey against the Bond/Barratt model for SAB circuit.
 ===Circuit Description and Inputs===
@@ Line 16: / Line 18: @@
 * 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)
 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:
 * Measured SAG mill power draw= 8,910 kW (11,950 hp).
 ** Assumed to be DCS indication.
-** Modelled conditions to match power draw: balls=16% v/v; filling=31% v/v; speed=75% c/s; 6" liner.
+** Modelled conditions to match power draw: balls=16.5% v/v; filling=31% v/v; speed=75% c/s; 6" liner.
-* Measured Ball mill power draw= 10,330 kW (13,850 hp, sum of two mills).
+* Measured Ball mill power draw= 10,330 kW (13,850 hp, sum of two mills or 5165 kW/6925 HP each).
 ** Assumed to be DCS indication.
-** Modelled conditions to match power draw: filling=29% v/v; speed=74% c/s; 6" liner.
+** Modelled conditions to match power draw: filling=27.5% v/v; speed=72% c/s; 6" liner.
 * Measured throughput= ''1733 t/h'' (1910 st/h)
@@ Line 40: / Line 42: @@
 * Bond/Barratt model ''E<sub>total</sub>= 11.95 kWh/t'' (model 13% high)
 * Bond/Barrat model Wi<sub>O</sub>= ''16.6 kWh/t'' (model 13% high)
-* Bond/Barratt model throughput= ''1522 t/h'' (model 13% low)
+* Bond/Barratt model throughput= ''1513 t/h'' (model 13% low)
 Result for default model conditions:
@@ Line 54: / Line 56: @@
 | Model
 | 11.95
-| 16.60
+| 16.62
 | kWh/t
-| 1,522
+| 1,513
 | t/h
 |-
@@ Line 68: / Line 70: @@
 | Difference
 | 1.45
-| 1.99
+| 2.01
 | kWh/t
-| 211
+| 220
 | t/h
 |-
 | Difference
 | 12.9%
-| 12.8%
+| 13.8%
+|
-| 12.9%
+| 12.7%
+|
 |}

@@ Line 16: / Line 16: @@
 * 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)
 Circuit operating work index is given in the paper as 13.4 kWh/st, which would convert to 14.0 kWh/t at mill shell. Checking the math:
@@ Line 25: / Line 34: @@
 <math>  Wi_O  = \frac{10.5}{ \left( {10\over \sqrt{178} }- {10\over \sqrt{106000} } \right) } = 14.61 \hbox{ kWh/t}</math>
 * Circuit operating work index to use for benchmarking is 14.6 kWh/t
 ===Default Model Results===

@@ Line 80: / Line 80: @@
 ===Model Tuning===
-The Bond/Barratt model is tuned using a '''contingency''' on the Single Stage Ball Mill specific energy consumption estimate (E<sub>ssbm</sub>).
+The Bond/Barratt model is tuned using a ''calibration factor'' on the Single Stage Ball Mill specific energy consumption estimate (E<sub>ssbm</sub>).
-* E<sub>ssbm</sub> = 10.39 kWh/t
+* Calculated E<sub>ssbm</sub> = 10.39 kWh/t
 * Measured E<sub>total</sub> = 10.50 kWh/t
-* Measured model contingency = 1%
+* Model calibration factor = 1%

@@ Line 19: / Line 19: @@
 Circuit operating work index is given in the paper as 13.4 kWh/st, which would convert to 14.0 kWh/t at mill shell. Checking the math:
-<math> E_{total} = 10.5 \hbox{ kWh/t} = Wi_O \times \left( \frac{10}{\sqrt{178} }- \frac{10}{ \sqrt{106000} } \right)</math>
+<math> E_{total} = 10.5 \hbox{ kWh/t} = Wi_O \times \left( \tfrac{10}{\sqrt{178} }- \tfrac{10}{ \sqrt{106000} } \right)</math>
 Reorganize to solve for Wi<sub>O</sub>:
 <math>  Wi_O  = \frac{10.5}{ \left( {10\over \sqrt{178} }- {10\over \sqrt{106000} } \right) } = 14.61 \hbox{ kWh/t}</math>
 * Circuit operating work index to use for benchmarking is 14.6 kWh/t

@@ Line 1: / Line 1: @@
 [[Category: Benchmarking]]
 [[Category: Bond/Barratt Model]]
 ==Benchmarking: Bond/Barratt - Fort Knox==
 * ''Magnuson, R.; Hallow, J.; Mosher, J.; Major, K.'', '''The Fort Knox Mill: Design, Commissioning and Operation'''. Proceedings of the SAG 2001 Conference, Vancouver, Canada.

← Older revision		Revision as of 20:18, 17 November 2012
Line 1:		Line 1:
		+	[[Category: Benchmarking]]
		+	[[Category: Bond/Barratt Model]]
	==Benchmarking: Bond/Barratt - Fort Knox==		==Benchmarking: Bond/Barratt - Fort Knox==
	* ''Magnuson, R.; Hallow, J.; Mosher, J.; Major, K.'', '''The Fort Knox Mill: Design, Commissioning and Operation'''. Proceedings of the SAG 2001 Conference, Vancouver, Canada.		* ''Magnuson, R.; Hallow, J.; Mosher, J.; Major, K.'', '''The Fort Knox Mill: Design, Commissioning and Operation'''. Proceedings of the SAG 2001 Conference, Vancouver, Canada.

@@ Line 2: / Line 2: @@
 * ''Magnuson, R.; Hallow, J.; Mosher, J.; Major, K.'', '''The Fort Knox Mill: Design, Commissioning and Operation'''. Proceedings of the SAG 2001 Conference, Vancouver, Canada.
-Checking the July 1999 survey against the Bond/Barratt model for SAB circuit.  Using 15% E<sub>ssbm</sub> contingency.
+Checking the July 1999 survey against the Bond/Barratt model for SAB circuit.
 The paper is believed 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.
@@ Line 12: / Line 13: @@
 * 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)
 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:
@@ Line 22: / Line 27: @@
 ** Conditions to match power draw: filling=29% v/v; speed=74% c/s; 6" liner.
 * Measured throughput= ''1733 t/h'' (1910 st/h)
 Result for default model conditions:
@@ Line 43: / Line 54: @@
 | Measured
 | 10.50
-| 13.97
+| 14.61
 | kWh/t
 | 1,733
@@ Line 50: / Line 61: @@
 | Difference
 | 1.45
-| 2.63
+| 1.99
 | kWh/t
 | 211
@@ Line 57: / Line 68: @@
 | Difference
 | 12.9%
-| 17.2%
+| 12.8%
+|
 | 12.9%
+|
 |}