Benchmarking: Bond - Cadia East - Revision history

Munashe Kurisa: /* Model results */

2020-05-21T23:55:58Z

Model results

← Older revision		Revision as of 23:55, 21 May 2020
Line 46:		Line 46:
	\|-		\|-
	\| Model		\| Model
	\| 12.2 kWh/t		\| 12.31 kWh/t
	\| 15.1 kWh/t		\| 14.94 kWh/t
	\| 27.7 kWh/t		\| 27.7 kWh/t
	\| ~~1294~~ t/h		\| 1243 t/h
	\|-		\|-
	\| Measured		\| Measured
Line 58:		Line 58:
	\|-		\|-
	\| Difference		\| Difference
	\| 1.6 kWh/t		\| 1.71 kWh/t
	\| 1.9 kWh/t		\| 1.74 kWh/t
	\| 3.9 kWh/t		\| 3.9 kWh/t
	\| -~~188~~ t/h		\| -239 t/h
	\|-		\|-
	\| Difference		\| Difference
	\| 15%		\| 16.13%
	\| 14%		\| 13.18%
	\| 16%		\| 16.39%
	\| -13%		\| -16.13%
	\|}		\|}

			<gallery>
			File:CadiaEast.png\|thumb\|Cadia East circuit
			File:CadiaEast-SAG.png\|thumb\|Cadia East SAG mill
			File:CadiaEast-BM.png\|thumb\|Cadia East Ball mill
			File:Cadia-Pebble.png\|thumb\|Cadia East Pebble crusher
			</gallery>

	The predicted transfer size needed to balance the power draw between primary & second mills is very coarse, 5 mm.		The predicted transfer size needed to balance the power draw between primary & second mills is very coarse, 5 mm.

Alex Doll: /* Modelling */

2015-03-15T19:37:07Z

Modelling

← Older revision		Revision as of 19:37, 15 March 2015
Line 34:		Line 34:
	* ball mills operating 37% v/v total filling and 70% w/w solids (fixed speed mills, 72% of critical speed)		* ball mills operating 37% v/v total filling and 70% w/w solids (fixed speed mills, 72% of critical speed)

	The ball load required to match the reported power draw is very high, and could only be achieved with a significant reduction in the trunnion diameter (using ball retaining rings). Moreover, the motors are predicted to be operating at 100.5% of their rated output power to ~~achive~~ the indicated power draw.		The ball load required to match the reported power draw is very high, and could only be achieved with a significant reduction in the trunnion diameter (using ball retaining rings). Moreover, the motors are predicted to be operating at 100.5% of their rated output power to achieve the indicated power draw.

	===Model results===		===Model results===

Alex Doll: /* Modelling */

2015-02-28T01:10:54Z

Modelling

← Older revision		Revision as of 01:10, 28 February 2015
Line 32:		Line 32:
	The mill load, ball charge and pulp density was tweaked to mimic these power draws, corresponding to:		The mill load, ball charge and pulp density was tweaked to mimic these power draws, corresponding to:
	* SAG operating 9% v/v balls, 25.5% v/v total filling and 78% of critical speed (Austin model has fixed %solids)		* SAG operating 9% v/v balls, 25.5% v/v total filling and 78% of critical speed (Austin model has fixed %solids)
	* ball mills operating 37% v/v total filling and 70% w/w solids (fixed speed mills, 72% speed)		* ball mills operating 37% v/v total filling and 70% w/w solids (fixed speed mills, 72% of critical speed)

	The ball load required to match the reported power draw is very high, and could only be achieved with a significant reduction in the trunnion diameter (using ball retaining rings). Moreover, the motors are predicted to be operating at 100.5% of their rated output power to achive the indicated power draw.		The ball load required to match the reported power draw is very high, and could only be achieved with a significant reduction in the trunnion diameter (using ball retaining rings). Moreover, the motors are predicted to be operating at 100.5% of their rated output power to achive the indicated power draw.

Alex Doll: /* Model results */

2015-01-31T21:29:59Z

Model results

← Older revision		Revision as of 21:29, 31 January 2015
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	! E<sub>ball</sub>		! E<sub>ball</sub>
	! E<sub>total</sub>		! E<sub>total</sub>
			! Throughput
	\|-		\|-
	\| Model		\| Model
Line 69:		Line 70:
	\|}		\|}

	The predicted transfer size needed to balance the power draw between primary & second mills is very coarse, 5 mm.		The predicted transfer size needed to balance the power draw between primary & second mills is very coarse, 5 mm.

	===Discussion===		===Discussion===

Alex Doll: /* Modelling */

2015-01-31T21:29:19Z

Modelling

← Older revision		Revision as of 21:29, 31 January 2015
Line 34:		Line 34:
	* ball mills operating 37% v/v total filling and 70% w/w solids (fixed speed mills, 72% speed)		* ball mills operating 37% v/v total filling and 70% w/w solids (fixed speed mills, 72% speed)

	The ball load required to match the reported power draw is very high, and could only be achieved with a significant reduction in the trunnion diameter (using ball retaining rings). Moreover, the motors are predicted to be operating at 100.5% of their rated output power to achive the indicated power draw~~; drawing full power~~.		The ball load required to match the reported power draw is very high, and could only be achieved with a significant reduction in the trunnion diameter (using ball retaining rings). Moreover, the motors are predicted to be operating at 100.5% of their rated output power to achive the indicated power draw.

	===Model results===		===Model results===

Alex Doll: /* Model results */

2015-01-31T21:05:01Z

Model results

← Older revision		Revision as of 21:05, 31 January 2015
Line 68:		Line 68:
	\| -13%		\| -13%
	\|}		\|}

			The predicted transfer size needed to balance the power draw between primary & second mills is very coarse, 5 mm.

			===Discussion===
			There is a substantial difference between the survey and the predictions. Some observations:
			* The rod mill work index was determined on an apparatus with smooth liners. This can cause a difference of 2-3 kWh/t versus the wave-liner apparatus specified by Bond. Using a rod mill work index of 24.0 kWh/t gives E<sub>total</sub> = 26.8 kWh/t; still 13% high.
			* The E<sub>ssbm</sub> predicts the energy required for a "standard" secondary crushing & ball milling plant that is believed to be one of the most energy efficient types of grinding circuits. This ore has E<sub>ssbm</sub> = 24.3 kWh/t which is still less than the survey E<sub>total</sub>. Very odd result that a SABC circuit is more efficient than an SSBM (ergo, HPGR) circuit on such a hard ore.

Alex Doll: /* Ore characterization */

2015-01-31T20:50:16Z

Ore characterization

← Older revision		Revision as of 20:50, 31 January 2015
Line 14:		Line 14:
	** DWI = 9.9		** DWI = 9.9
	** density = 2.7 t/m³		** density = 2.7 t/m³

			The ore was reported blasted undergrond (block caving had not yet started). Particle size distribution given as two points which confirm a Bond-compatible "root-2" PSD.
			* 80% passing 80 mm
			* 20% passing 5 mm

	===Modelling===		===Modelling===

Alex Doll: Created page with "category:benchmarking category:Bond/Barratt Model ==Benchmarking: Bond/Barratt - Cadia== ''Engelhardt, D., Robertson, J., Lane, G., Powwel, M.S. and Griffin, P.'', '''..."

2015-01-31T20:21:46Z

Created page with "category:benchmarking category:Bond/Barratt Model ==Benchmarking: Bond/Barratt - Cadia== ''Engelhardt, D., Robertson, J., Lane, G., Powwel, M.S. and Griffin, P.'', '''..."

New page

[[category:benchmarking]]
[[category:Bond/Barratt Model]]
==Benchmarking: Bond/Barratt - Cadia==
''Engelhardt, D., Robertson, J., Lane, G., Powwel, M.S. and Griffin, P.'', '''Cadia Expansion - From open pit to block cave and beyond'''. Proceedings of MetSoc 2012.

Design criteria and plant trial of underground Cadia East ore

===Ore characterization===
* blased underground ore, secondary crushed to 80 mm.
** WiC = 30 (metric)
** WiRM = 26.5 (metric)
** WiBM = 21.4 (metric)
** DWI = 9.9
** density = 2.7 t/m³

===Modelling===

Details of the mill operating conditions are not given, but the power draw at the shell is given.
* 15.737 MW SAG mill power draw
* 19.509 MW ball mill power draw

Circuit operating conditions:
* F80 = 80 mm
* P80 = 140 µm
* instantaneous throughput = 1482 t/h

The mill load, ball charge and pulp density was tweaked to mimic these power draws, corresponding to:
* SAG operating 9% v/v balls, 25.5% v/v total filling and 78% of critical speed (Austin model has fixed %solids)
* ball mills operating 37% v/v total filling and 70% w/w solids (fixed speed mills, 72% speed)

The ball load required to match the reported power draw is very high, and could only be achieved with a significant reduction in the trunnion diameter (using ball retaining rings). Moreover, the motors are predicted to be operating at 100.5% of their rated output power to achive the indicated power draw; drawing full power.

===Model results===
{| class="wikitable" border="1"
|-
!
! ESAG
! Eball
! Etotal
|-
| Model
| 12.2 kWh/t
| 15.1 kWh/t
| 27.7 kWh/t
| 1294 t/h
|-
| Measured
| 10.6 kWh/t
| 13.2 kWh/t
| 23.8 kWh/t
| 1482 t/h
|-
| Difference
| 1.6 kWh/t
| 1.9 kWh/t
| 3.9 kWh/t
| -188 t/h
|-
| Difference
| 15%
| 14%
| 16%
| -13%
|}