Difference between revisions of "Benchmarking: Bond - Macraes"

From SAGMILLING.COM
Jump to: navigation, search
(Created page with "==Benchmarking: Bond/Barratt Circuit Specific Energy Consumption - Macraes== ''Barns, K., Lane, G., Osten, K. & Scagliotta, N.'', '''Benchmarking Energy Efficiency - A Ca...")
 
(→‎Comparison)
 
(4 intermediate revisions by the same user not shown)
Line 1: Line 1:
  +
[[category: Benchmarking]]
  +
[[category: Bond/Barratt Model]]
  +
[[category:Bibliography]]
 
==Benchmarking: Bond/Barratt Circuit Specific Energy Consumption - Macraes==
  
==Benchmarking: Bond/Barratt Circuit Specific Energy Consumption - Macraes==
   
Line 38: Line 41:
 
! !! !! Survey 5 !! Survey 4 !! Survey 3 !! Survey 2 !! Survey 1
  
! !! !! Survey 5 !! Survey 4 !! Survey 3 !! Survey 2 !! Survey 1
 
|-
  
|-
−
| SAG specific power || kW at shell || 3.6 || 4.8 || 4.1 || 3.8 || 3.6
 +
| SAG specific energy || kWh/t at shell || 3.6 || 4.8 || 4.1 || 3.8 || 3.6
 
|-
  
|-
−
| ball mill specific power || kW at shell || 8.1 || 8.3 || 7.4 || 7.4 || 7.2
 +
| ball mill specific energy || kWh/t at shell || 8.1 || 8.3 || 7.4 || 7.4 || 7.2
 
|-
  
|-
−
| total specific power || kW at shell || 11.8 || 13.0 || 11.4 || 11.2 || 10.8
 +
| total specific energy || kWh/t at shell || 11.8 || 13.0 || 11.4 || 11.2 || 10.8
 
|-
  
|-
 
| grindability, Wi<sub>RM</sub> || kWh/t || 9.5 || 10.1 || 9.8 || 8.8 || 9.5
  
| grindability, Wi<sub>RM</sub> || kWh/t || 9.5 || 10.1 || 9.8 || 8.8 || 9.5
Line 54: Line 57:
   
 
===Model Results===
  
===Model Results===
−  
−
Model results:
  
   
 
{| class="wikitable"
  
{| class="wikitable"
Line 61: Line 62:
 
! !! !! Survey 5 !! Survey 4 !! Survey 3 !! Survey 2 !! Survey 1
  
! !! !! Survey 5 !! Survey 4 !! Survey 3 !! Survey 2 !! Survey 1
 
|-
  
|-
−
| SAG specific power || kW at shell || 3.41 || 4.56 || 4.36 || 3.82 || 3.68
 +
| SAG specific energy || kWh/t at shell || 3.41 || 4.56 || 4.36 || 3.82 || 3.68
 
|-
  
|-
−
| ball mill specific power || kW at shell || 7.59 || 7.91 || 7.67 || 7.54 || 7.43
 +
| ball mill specific energy || kWh/t at shell || 7.59 || 7.91 || 7.67 || 7.54 || 7.43
 
|-
  
|-
−
| total specific power || kW at shell || 11.00 || 12.5 || 12.02 || 11.36 || 11.11
 +
| total specific energy || kWh/t at shell || 11.00 || 12.5 || 12.02 || 11.36 || 11.11
 
|-
  
|-
 
| transfer size, T<sub>80</sub><br>to achieve E<sub>SAG</sub>/E<sub>ball</sub> ratio || &micro;m || 4200|| 2000 || 2000 || 2700 || 3250
  
| transfer size, T<sub>80</sub><br>to achieve E<sub>SAG</sub>/E<sub>ball</sub> ratio || &micro;m || 4200|| 2000 || 2000 || 2700 || 3250
 
|}
  
|}
   
−
It is important to remember that the Bond/Barratt equation for total circuit power (E<sub>total</sub>) is independent of transfer size. The transfer size is only used to split total circuit power between the SAG and ball mills. The difference between measured and predicted transfer sizes only affects the split of power between the milling stages and not the overall circuit power.
 +
It is important to remember that the Bond/Barratt equation for total circuit specific energy (E<sub>total</sub>) is independent of transfer size. The transfer size is only used to split total circuit power between the SAG and ball mills. The difference between measured and predicted transfer sizes only affects the split of power between the milling stages and not the overall circuit power.
   
 
===Comparison===
  
===Comparison===
Line 79: Line 80:
 
! !! !! Survey 5 !! Survey 4 !! Survey 3 !! Survey 2 !! Survey 1 !! Overall<br>Average
  
! !! !! Survey 5 !! Survey 4 !! Survey 3 !! Survey 2 !! Survey 1 !! Overall<br>Average
 
|-
  
|-
−
| SAG specific power || ||-5.3% ||-5.0% || 6.3% || 0.5% || 2.2% || -0.2%
 +
| SAG specific energy || ||-5.3% ||-5.0% || 6.3% || 0.5% || 2.2% || -0.2%
 
|-
  
|-
−
| ball mill specific power || ||-6.3% ||-4.7% || 3.6% || 1.9% || 3.2% || -0.5%
 +
| ball mill specific energy || ||-6.3% ||-4.7% || 3.6% || 1.9% || 3.2% || -0.5%
 
|-
  
|-
−
| total specific power || ||-6.8% ||-3.8% || 5.4% || 1.4% || 2.9% || -0.2%
 +
| total specific energy || ||-6.8% ||-3.8% || 5.4% || 1.4% || 2.9% || -0.2%
 
|-
  
|-
 
| transfer size, T80 || ||428.3% ||-39.7% || 148.8% || 21.9% || 59.1% || 123.7%
  
| transfer size, T80 || ||428.3% ||-39.7% || 148.8% || 21.9% || 59.1% || 123.7%

Latest revision as of 16:34, 15 June 2017

Benchmarking: Bond/Barratt Circuit Specific Energy Consumption - Macraes

Barns, K., Lane, G., Osten, K. & Scagliotta, N., Benchmarking Energy Efficiency - A Case Study at Macraes Gold Mine, Proceedings of the AusIMM MetPlant conference, Perth, Australia, September 2004.

Raw data from paper

The paper describes overall plant unit operation efficiency rather that specific grinding mill surveys, but does reference five surveys that are useful for benchmarking.

Survey 5 Survey 4 Survey 3 Survey 2 Survey 1
throughput dry t/h 536 454 493 514 527
SAG feed F80 mm 82.9 106.8 72.7 56.8 51.4
SAG specific power kW at DCS 3.84 5.04 4.32 4.02 3.76
ball mill specific power kW at DCS 8.60 8.76 7.78 7.86 7.63
transfer size, T80 µm 795 3318 804 2215 2043
cyclone overflow size, P80 µm 100 100 100 117 116
grindability, SPI minutes 40.7 46.3 43.2 34.7 40.5
grindability, WiBM kWh/t 10.3 11.6 11.3 11.9 11.4

Interpretation and Interpolation

Assume that the power provided at the motor input is converted to shell power using 0.96 motor efficiency and 0.985 gear efficiency for an overall conversion of 0.9456.

The paper gives interpolated values for the rod mill work index, but those do not appear to be calibrated to a "Bond" style rod mill with wave liners. Use the WiRM calibration to SGI from the Example database, these are the interpolated rod mill work index numbers that can be used for the Bond/Barratt method. No crushing work index values are given; assume that WiC = WiRM for modelling.

Survey 5 Survey 4 Survey 3 Survey 2 Survey 1
SAG specific energy kWh/t at shell 3.6 4.8 4.1 3.8 3.6
ball mill specific energy kWh/t at shell 8.1 8.3 7.4 7.4 7.2
total specific energy kWh/t at shell 11.8 13.0 11.4 11.2 10.8
grindability, WiRM kWh/t 9.5 10.1 9.8 8.8 9.5

The transfer sizes are assumed to be "as-measured" and have not been subjected to a 'phantom cyclone' fine removal. The transfer size in the Bond/Barratt model (because it excludes 'additional' fines) will be iterated to give the ESAG/Eball ratio reported. The different between the iterated T80 and the measured T80 will be assumed to be the "phantom cyclone effect".

Because full mill surveys aren't given, abbreviated model runs are used in this benchmarking rather than full models (there is no saved data to view).

Use Bond/Barratt SABC model with 10% SSBM contingency.

Model Results

Survey 5 Survey 4 Survey 3 Survey 2 Survey 1
SAG specific energy kWh/t at shell 3.41 4.56 4.36 3.82 3.68
ball mill specific energy kWh/t at shell 7.59 7.91 7.67 7.54 7.43
total specific energy kWh/t at shell 11.00 12.5 12.02 11.36 11.11
transfer size, T80
to achieve ESAG/Eball ratio		 µm 4200 2000 2000 2700 3250

It is important to remember that the Bond/Barratt equation for total circuit specific energy (Etotal) is independent of transfer size. The transfer size is only used to split total circuit power between the SAG and ball mills. The difference between measured and predicted transfer sizes only affects the split of power between the milling stages and not the overall circuit power.

Comparison

Difference between model results and plant surveys:

Survey 5 Survey 4 Survey 3 Survey 2 Survey 1 Overall
Average
SAG specific energy -5.3% -5.0% 6.3% 0.5% 2.2% -0.2%
ball mill specific energy -6.3% -4.7% 3.6% 1.9% 3.2% -0.5%
total specific energy -6.8% -3.8% 5.4% 1.4% 2.9% -0.2%
transfer size, T80 428.3% -39.7% 148.8% 21.9% 59.1% 123.7%
Retrieved from "https://wiki.sagmilling.com/index.php?title=Benchmarking:_Bond_-_Macraes&oldid=1126"