Crushing, Screening & Conveying

Crushing, Screening & Conveying2017-04-04T06:57:13-04:00
  • To participate in the 911Metallurgist Forums, be sure to JOINLOGIN
  • Use Add New Topic to ask a New Question/Discussion about Crushing.
  • OR Select a Topic that Interests you.
  • Use Add Reply = to Reply/Participate in a Topic/Discussion (most frequent).
    Using Add Reply allows you to Attach Images or PDF files and provide a more complete input.
  • Use Add Comment = to comment on someone else’s Reply in an already active Topic/Discussion.

SAG mill VS Ball & Rod Mill (2 replies and 1 comment)

Nikita Gupta
2 months ago
Nikita Gupta 2 months ago

I would like to understand why do companies use SAG mills instead of Rod mills for grinding these days? Apart from the alleviation of need for secondary and tertiary crushers, is there any other reason for inclination towards the installation of SAG mills. 

SmartDog
2 months ago
SmartDog 2 months ago

The main reason is capacity versus plant area.  Rod mills have a major restriction in length to diameter, they have to be significantly longer than their diameter to prevent the rods from tumbling and turning into a twisted knot.  SAG mills are the opposite, they generally have a larger diameter than their length.  This gives them an inherent higher capacity for a given length.  Rods are also generally more expensive than balls and harder to handle.  This means a rod mill equal in capacity to a ball or SAG mill would take up more plant floor area requiring a larger building.

Also since SAG (semi-autogenous grinding) uses less media than a comparable rod or even ball mill.  While less efficient in actual grinding SAG mills are lower capital and operating cost per unit ground, especially at large particle sizes.

Nikita Gupta
2 months ago

I actually did a cost benefit analysis and found that for use, the per unit cost was lower in the stream that used Rod Mills as compared to SAG mill. Is this an anamoly?

Alex Doll
2 months ago
Alex Doll 2 months ago

In addition to issues described in the earlier comment, you can make SAG mills bigger than rod mills.  The largest SAG mills consume around 25,000 kW whilst the largest rod mills consume less then 2,500 kW.  It is better to install one large SAG mill than 10 small rod mills.

Please join and login to participate and leave a comment.

BUY Laboratory & Small Plant Process Equipment

We have all the laboratory and plant equipment you need to test or build/operate your plant.

ENTER our Mining Equipment' Store

We Sell EQUIPMENT for all types of Mineral Treatment PROCESSES and Laboratory Testing needs

Do you need METALLURGICAL TESTING of your ORE?

View the Services we Provide

911Metallurgist Mineral Processing & Process Development Laboratory

We have a metallurgical test for every possible mineral type and treatment.

Need ENGINEERING Services or Plant TROUBLESHOOTING?

We can IMPROVE ALL PLANTS / Mineral Processing Engineering & LABORATORY Ore Testing

911Metallurgy Engineering

Contact us for process engineering, metallurgical investigations, plant optimization, plant troubleshooting, needs. WE “FIX” METALLURGY.

I Need Consulting Engineering Help
I Need Ore Laboratory Testing