# Crushing, Screening & Conveying

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## How to theoretically calculate energy consumption of various types of crushers - Jaw/ Gyratory/ Con ... (1 reply)

pandamanishankar
2 months ago
pandamanishankar 2 months ago

I am working on budgeting the costs for an copper processing plant and need to estimate potential power consumption of jaw crusher? I have work index, F80 and P80 of the ore.

Any guidance is really appreciated?

Alex Doll
2 months ago
Alex Doll 2 months ago
1 like by David

The specific energy consumption at the motor input can be predicted using Bond's equation:

E = 10 × CWi × (P80½ - F80–½)

where CWi is your work index, F80 is the 80% passing size of the feed measured in µm, and P80 is the 80% passing size of the product measured in µm.  E is the specific energy in kWh/tonne.

Very important -- there are five types of work index.  This equation for crushing must use the "crushing work index" and not a "ball mill work index".  If the work index you were given was determined using a ball mill test, then you don't have the correct information.

You'll need to allow for motor and electrical network losses of 10% to 15% when computing your operating costs.

Do not use this equation to size the motor!!! The peak torque needed is a function of clearing a jam and not normal operation.  Usually the crusher vendor will choose a motor big enough to clear the jam if you tell then application (they will have experience telling them the proper motor size).