Benchmarking: Bond - Santa Rita - Revision history

Alex Doll: /* Design Criteria */

2020-04-30T22:27:37Z

Design Criteria

Munashe Kurisa: added EGL for both the SAG and Ball Mill

2020-04-30T20:30:36Z

added EGL for both the SAG and Ball Mill

Alex Doll: /* Circuit Simulation */

2017-04-15T21:58:13Z

Circuit Simulation

Alex Doll: /* Circuit Simulation */

2014-01-26T02:05:18Z

Circuit Simulation

Alex Doll: /* Circuit Simulation */

2014-01-26T01:59:36Z

Circuit Simulation

Alex Doll: /* Design Criteria */

2014-01-26T01:16:37Z

Design Criteria

Alex Doll at 00:49, 26 January 2014

2014-01-26T00:49:23Z

Alex Doll at 22:01, 27 January 2013

2013-01-27T22:01:24Z

Alex Doll: Created page with "category:Benchmarking category:Bibliography category:Bond/Barratt model ==Benchmarking: Bond/Barratt Specific Energy Consumption - Santa Rita== ''Latchireddi, S. ..."

2013-01-27T21:59:36Z

Created page with "category:Benchmarking category:Bibliography category:Bond/Barratt model ==Benchmarking: Bond/Barratt Specific Energy Consumption - Santa Rita== ''Latchireddi, S. ..."

New page

[[category:Benchmarking]]
[[category:Bibliography]]
[[category:Bond/Barratt model]]
==Benchmarking: Bond/Barratt Specific Energy Consumption - Santa Rita==

''Latchireddi, S. & Faria, E.'', '''Achievement of High Energy Efficiency in Grinding Mills at Santa Rita''', Proceedings of the Canadian Mineral Processors Annual General Meeting, Ottawa, Canada, January 2013.

''Faria, E. & Latchireddi, S.'', '''Commissioning and Operation of Milling Circuit at Santa Rita Nickel Operation''', Paper #137: Proceedings of the International Autogenous Grinding, Semiautogenous Grinding and High Pressure Grinding Roll Technology Conference, Vancouver, Canada, September 2011.

==Design Criteria==

A survey was conducted on July 15, 2010 and reported the following:
* Ore A×b 50.2
* Ore ball mill work index 18.4 kWh/tonne
* Circuit FAG mill feed F80 141 mm
* Circuit cyclone overflow P80 146 µm

To run the Bond/Barratt model requires work index values for rod milling and crushing. The reported A×b (50.2) is similar to these values:
* WiRM 15.0 kWh/tonne
* WiC 15.0 kWh/tonne

==Model parameter fitting==

The following tables back-calculate the "Essbm contingency" model fitting parameter for the Bond/Barratt SABC model (which includes allowance for phantom cyclone effects). Specific energy references the "mill shell" kW values (note that specific energy values in the references relate to power at the DCS).

{|class="wikitable" border="1"
! !!FAG!!BM!!Peb Crusher!!Etotal
|-
| DCS kW||6,667||5,082||||
|-
| Shell kW||6,208||4,732||224||
|-
| Throughput, t/h||650||650||650||
|-
| Specific Energy, kWh/t||9.55||7.28||0.34||17.18
|-
| Essbm||||||||16.82
|-
| contingency||||||||2.1%
|}

The default model contingency is 10%, so this circuit is operating more efficiently. Note that the lack of actual work index measurements in the rod mill and crushing size classes means there is uncertainty in the Essbm measurement used to estimate the contingency.

==Circuit Simulation==
[[File:Benchmarking-Santa_Rita.png|thumb|Screenshot of the Santa Rita circuit simulation]]
Combining the Bond/Barratt specific energy model, the Austin FAG model described in the [[Benchmarking: Santa Rita FAG|bibliography]] and the Morrell ball mill model described in the [[Benchmarking: Santa Rita ball mill model|bibliography]] results in the following throughput predictions using the work index values above:

* Actual FAG/ball motor powers (at shell): 6,208 kW / 4,732 kW
* Actual daily average throughput: 650 tonnes/hour
* Predicted FAG/ball motor powers (at shell): 5,785 kW / 4,420 kW
* Predicted nominal throughput: 564 tonnes/hour (14.2% difference)

{|class="wikitable" border="1"
! !!SAG!!BM!!Pebble Crusher!!total
|-
| Measured specific energy consumption, kWh/t||9.55||7.28||0.34||17.18
|-
| Predicted specific energy consumption, kWh/t||10.26||7.84||0.40||18.50
|-
| Difference, kWh/t||0.71||0.56||0.06||1.32
|-
| Difference, %||7.2%||7.4%||14.9%||7.4%
|}

The model specific energy consumption estimates are 7.4% higher than the actual values, and the mill model power draw estimates are about 7% lower than actual. The net effect is the throughput estimates are 14% lower for the model versus the survey.

@@ Line 16: / Line 16: @@
 * Circuit cyclone overflow P<sub>80</sub> 146 &micro;m
 * SAG mill: 30 foot diameter by 15.4 foot effective grinding length (EGL)
-* Ball mill: one 20 foot by 28.4 foot (assumed to be EGL)
+* Ball mill: one 20 foot by 28.4 foot EGL
 To run the Bond/Barratt model requires work index values for rod milling and crushing. The reported A&times;b (50.2) is similar to these values:

@@ Line 15: / Line 15: @@
 * Circuit FAG mill feed F<sub>80</sub> 141 mm
 * Circuit cyclone overflow P<sub>80</sub> 146 &micro;m
 To run the Bond/Barratt model requires work index values for rod milling and crushing. The reported A&times;b (50.2) is similar to these values:

@@ Line 50: / Line 50: @@
 * Actual FAG/ball motor powers (at shell): 6,208 kW / 4,732 kW
 * Actual daily average throughput: 650 tonnes/hour
-* Predicted FAG/ball motor powers (at shell):  5,555 kW / 4.734 kW
+* Predicted FAG/ball motor powers (at shell):  5,555 kW / 4,734 kW
-* Predicted nominal throughput: 564 tonnes/hour (14.2% difference)
+* Predicted nominal throughput: 568 tonnes/hour (14.4% difference)
 Additional criteria for modelling:
@@ Line 57: / Line 57: @@
 * ball mill loading 27.5% v/v
 * DCS to shell conversion 0.97 &times; 0.96 = 0.9312
-* liner thickness not given, assume 4.5 inches
+* SAG liner thickness not given, assume 4.5 inches
 * circuit F<sub>80</sub> 141 mm; P<sub>80</sub> 146 &micro;m
@@ Line 65: / Line 65: @@
 | Measured specific energy consumption, kWh/t||9.55||7.28||0.34||17.18
 |-
-| Predicted specific energy consumption, kWh/t||10.26||7.84||0.40||18.50
+| Predicted specific energy consumption, kWh/t||9.78||8.33||0.39||18.50
 |-
-| Difference, kWh/t||0.71||0.56||0.06||1.32
+| Difference, kWh/t||0.23||1.05||0.05||1.32
 |-
-| Difference, %||7.2%||7.4%||14.9%||7.4%
+| Difference, %||2.4%||14.4%||14.7%||7.7%
 |}
-The model specific energy consumption estimates are 7.4% higher than the actual values, and the mill model power draw estimates are about 7% lower than actual.  The net effect is the throughput estimates are 14% lower for the model versus the survey.
+The model specific energy consumption estimates are 7.7% higher than the actual values, and the mill model power draw estimates are about 6% lower than actual.  The net effect is the throughput estimates are 14% lower for the model versus the survey.

@@ Line 19: / Line 19: @@
 * Wi<sub>RM</sub> 15.0 kWh/tonne
 * Wi<sub>C</sub> 15.0 kWh/tonne
 ==Model parameter fitting==

@@ Line 52: / Line 52: @@
 {|class="wikitable" border="1"
-! !!SAG!!BM!!Pebble<br>Crusher!!total
+! !!FAG!!BM!!Pebble<br>Crusher!!total
 |-
 | Measured specific energy consumption, kWh/t||9.55||7.28||0.34||17.18

@@ Line 46: / Line 46: @@
 ==Circuit Simulation==
 [[File:Benchmarking-Santa_Rita.png|thumb|Screenshot of the Santa Rita circuit simulation]]
-Combining the Bond/Barratt specific energy model, the Austin FAG model described in the [[Benchmarking: Santa Rita FAG|bibliography]] and the Nordberg wet overflow ball mill model described in the [[Benchmarking: Santa Rita ball mill model|bibliography]] results in the following throughput predictions using the work index values above:
+Combining the Bond/Barratt specific energy model, the Austin FAG model described in the bibliography and the Nordberg wet overflow ball mill model described in the [[Benchmarking: Santa Rita ball mill model|bibliography]] results in the following throughput predictions using the work index values above:
 * Actual FAG/ball motor powers (at shell): 6,208 kW / 4,732 kW

@@ Line 1: / Line 1: @@
-[[category:Benchmarking]]
+[[category: Benchmarking]]
 [[category:Bibliography]]
 ==Benchmarking: Bond/Barratt Specific Energy Consumption - Santa Rita==