Difference between revisions of "Benchmarking: Bond - Esperanza"

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(Created page with "category:benchmarking ==Benchmarking: Bond/Barratt SAG Mill Specific Energy Consumption - Esperanza == * ''Villanueva, F. and Soto, L.'', '''SEC and the impact on a mills ...")
 
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[[category:benchmarking]]
 
[[category:benchmarking]]
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[[category:Bond/Barratt Model]]
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[[category:Bibliography]]
 
==Benchmarking: Bond/Barratt SAG Mill Specific Energy Consumption - Esperanza ==
 
==Benchmarking: Bond/Barratt SAG Mill Specific Energy Consumption - Esperanza ==
 
* ''Villanueva, F. and Soto, L.'', '''SEC and the impact on a mills selection for DMC project'''. Proceedings of the XXVII International Mineral Processing Congress, October 2014, Santiago, Chile. C14-23.
 
* ''Villanueva, F. and Soto, L.'', '''SEC and the impact on a mills selection for DMC project'''. Proceedings of the XXVII International Mineral Processing Congress, October 2014, Santiago, Chile. C14-23.
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Paper describes modelling of two expansion cases (Esperanza Sur and Encuentro). Some operating data for the current Esperanza pit & plant are provided as they were used to tune the comminution models used for the expansion cases.
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==Design Criteria==
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Actual operating data from Esperanza
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* A×b of Esperanza ore (Aug-Dec 2012); avg= 39; range is 30.7 to 45.5.
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* Wi<sub>BM</sub> average is 16.0 kWh/st, = 17.6 kWh/tonne.
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* E<sub>SAG</sub> for "normal" blasting, average = 5.2 kWh/tonne; range is 3.9 to 7.2 kWh/tonne.
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* E<sub>SAG</sub> for "high intensity" blasting typically 10% lower E<sub>SAG</sub>.
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* SAG feed size range 33.6% to 49.0 percent passing 1&frac14; inch (32 mm).
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A relationship for E<sub>SAG</sub> (as kWh/tonne) to A&times;b is given for Esperanza operating data:
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<math>E_{SAG} = 22,548 (A \times b)^{-0.356} </math>
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Design criteria for expansion cases (which may reflect Esperanza operating conditions)
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* SAG circuit F<sub>80</sub> = 132 mm
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* transfer T<sub>80</sub> = 3500 &micro;m (text erroneously says "3500 mm")
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* BM circuit P<sub>80</sub> = 180 &micro;m
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* SAG mill power utilization = 92.3%
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* Ball mill power utilization = 95%
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* Plant availability = 93%
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Mill criteria
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* SAG mill: 40 foot nom dia by 26 foot flange-to-flange cylinder length
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* ball mill: 27 foot nom dia by 45 foot flange-to-flange cylinder length (2 units)
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* SAG mill gearless motor 31,500 HP (given in Thiele & Parraguez, Relpas 2011 conference)
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* Ball mill gearless motors 25,000 HP
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(some references give 30,000 HP for SAG motor; this is thought to be the value excluding a 5% design margin)
  +
  +
==Modelling==
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  +
SAG mill is modelled using following:
  +
* Austin model
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* assume ore density 2.64 t/m³, same as Los Bronces
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* nominal diameter 40 foot, effective grinding length 26 foot (deduct 2 ft from cylinder length)
  +
* assume 6 inch liner effective thickness, mill speed 75% of critical
  +
* ball charge 16% v/v; total filling 26% v/v gives the desired 92.4% utilization of motor power
  +
  +
Ball mill is modelled using following:
  +
* Nordberg wet overflow model
  +
* assume ore density 2.64 t/m³, same as Los Bronces
  +
* nominal diameter 27 foot, effective grinding length 44.5 foot (deduct 6 inches from cylinder length)
  +
* assume 6 inch liner effective thickness, mill speed 75% of critical
  +
* total filling 30% v/v gives the desired 95% utilization of motor power

Revision as of 03:24, 9 January 2015

Benchmarking: Bond/Barratt SAG Mill Specific Energy Consumption - Esperanza

  • Villanueva, F. and Soto, L., SEC and the impact on a mills selection for DMC project. Proceedings of the XXVII International Mineral Processing Congress, October 2014, Santiago, Chile. C14-23.

Paper describes modelling of two expansion cases (Esperanza Sur and Encuentro). Some operating data for the current Esperanza pit & plant are provided as they were used to tune the comminution models used for the expansion cases.

Design Criteria

Actual operating data from Esperanza

  • A×b of Esperanza ore (Aug-Dec 2012); avg= 39; range is 30.7 to 45.5.
  • WiBM average is 16.0 kWh/st, = 17.6 kWh/tonne.
  • ESAG for "normal" blasting, average = 5.2 kWh/tonne; range is 3.9 to 7.2 kWh/tonne.
  • ESAG for "high intensity" blasting typically 10% lower ESAG.
  • SAG feed size range 33.6% to 49.0 percent passing 1¼ inch (32 mm).

A relationship for ESAG (as kWh/tonne) to A×b is given for Esperanza operating data:

E_{SAG} = 22,548 (A \times b)^{-0.356}

Design criteria for expansion cases (which may reflect Esperanza operating conditions)

  • SAG circuit F80 = 132 mm
  • transfer T80 = 3500 µm (text erroneously says "3500 mm")
  • BM circuit P80 = 180 µm
  • SAG mill power utilization = 92.3%
  • Ball mill power utilization = 95%
  • Plant availability = 93%

Mill criteria

  • SAG mill: 40 foot nom dia by 26 foot flange-to-flange cylinder length
  • ball mill: 27 foot nom dia by 45 foot flange-to-flange cylinder length (2 units)
  • SAG mill gearless motor 31,500 HP (given in Thiele & Parraguez, Relpas 2011 conference)
  • Ball mill gearless motors 25,000 HP

(some references give 30,000 HP for SAG motor; this is thought to be the value excluding a 5% design margin)

Modelling

SAG mill is modelled using following:

  • Austin model
  • assume ore density 2.64 t/m³, same as Los Bronces
  • nominal diameter 40 foot, effective grinding length 26 foot (deduct 2 ft from cylinder length)
  • assume 6 inch liner effective thickness, mill speed 75% of critical
  • ball charge 16% v/v; total filling 26% v/v gives the desired 92.4% utilization of motor power

Ball mill is modelled using following:

  • Nordberg wet overflow model
  • assume ore density 2.64 t/m³, same as Los Bronces
  • nominal diameter 27 foot, effective grinding length 44.5 foot (deduct 6 inches from cylinder length)
  • assume 6 inch liner effective thickness, mill speed 75% of critical
  • total filling 30% v/v gives the desired 95% utilization of motor power