Grinding & Classification Circuits

Grinding & Classification Circuits

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Bond Ball mill work index determination (1 reply)

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srinu1234
6 years ago
srinu1234 6 years ago

Dear all, 

Have a good day! I am trying to determine ball mill work index for a very soft . If I follow bonds procedure to do experiment, not able to determine. The following is the data of ore sample.

F80% = 2300mic

Mesh of grind =300mic

-300mic in feed = 47%

In this case if the sample is grind by 100 revolution in ball mill as per bonds procedure , whole material is passed through 300mic sieve while sieving. Work index is as per plant operation data is 2.45kwh/short ton.

How to calculate Work index for above sample?  

Thanks & Regards ,

Srinivas

Alex Doll
6 years ago
Alex Doll 6 years ago
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The objective of the Bond work index tumbling tests is to arrive at a steady-state where the amount of ground material is constant between the stages.  One way to short-circuit the early instability due to the fines in your sample is to skip the first cycle and screen one mill charge volume of fresh feed, and then make up the screen undersize mass with fresh feed.  You then start at the second cycle with a small number of revolutions (the quantity of second stage cycles isn't critical); for example, just do the revolutions calculation as if you did run Cycle 1 at 100 rev and got x grams of undersize (47% of charge).

The critical cycles are the ones near the end of the test, where things are about to converge.  It is reasonable that you will converge to the ultimate answer no matter where you start; all you are changing is the direction that you are travelling to arrive at the ultimate destination.

https://www.sagmilling.com/

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