Grinding & Classification Circuits

Grinding & Classification Circuits2018-06-17T09:51:34-04:00
  • To participate in the 911Metallurgist Forums, be sure to JOINLOGIN
  • Use Add New Topic to ask a New Question/Discussion about Grinding.
  • 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.

KC feed preparation (5 replies and 3 comments)

Metals Guy
12 months ago
Metals Guy 12 months ago

I am having problems with the amount of tramp metal (from grinding media) that ends up in my knelson concentrator  and subsequently affecting recovery. The KC  is treating SAG mill primary cyclone underflow, KC feed size 4.5mm, KC model XD 30. Which is the best place to remove tramp metal, from the grinding circuit. The mill discharge or on the KC vibro feed screen?

Gene Cheeseman
12 months ago
Gene Cheeseman 12 months ago

If you can somehow manage to use 2-3 mm screen apertures you will reduce the amount of coarse steel out-competing fine gold in the concentrator and greatly reduce your bowl wear rates.

Assuming you are only treating a portion of the CUF by gravity you will need less mag-sep capacity by treating a bleed stream (like the scalping screen feed).  Drawing down your recirculating tramp steel load works just like gravity recovery of gold, by treating any portion of the circulating load you will be pulling out steal that will eventually report to your concentrator.  I have even seem mag-sep units treating concentrator tailings to keep the steel from getting back to the mill.


Metals Guy
12 months ago

Will reducing the KC feed size eliminate or rather it will allow finer sized metal into the KC, which again will be problematic during intensive cyanidation. Remember there would be no point where the steel is removed from the grinding circuit

Gene Cheeseman
12 months ago

This will not eliminate steel to the gravity concentrator but it is the easiest way to minimize the amount of steel getting into your concentrate, will likely lead to an increase in gravity recovery and give you longer bowl life; this is assuming your scalping screen is large enough to handle 2 mm apertures.

If the steel is causing problems in the intensive leach why not put your mag-sep on the gravity concentrate stream before entering the leach reactor?

I have heard of excessive amounts of steel causing issues in ILRs before but haven't experienced it in person. Can you describe your ILR circuit and what % steel you are talking about?

12 months ago
sagmill70 12 months ago

Agree with Gene. Run mill discharge over 2mm "with flow" screen panels fit on vibrating screen before material entering the Knelson Concentrator. That will helps you get rid off that scats material

12 months ago
SmartDog 12 months ago

As Gene and sagmill70 implied, tramp iron from broken balls and other sources will always be coming out of your mill.  Removing it has been a major milling issue almost from the beginning of SAG milling (and other milling also).   This is one of the reasons almost all SAG mills (and AG mills) have their discharge screened, with the oversize being conveyed to a crushing circuit or back to the feed with a tramp iron magnet on the conveyor.  I have heard of an attempt to have the discharge in a sluice with a magnet over the sluice, but never heard of how it worked out.

12 months ago
sagmill70 12 months ago

@Metals guy...How does your KC flow look likes? Any ICR in the flow to Goldroom?

11 months ago

whats your ball size, describe your discharge liner configuration, what type of classification screens in circuit. this i believe will expose the solution.

11 months ago
David 11 months ago

Same author, same topic

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


View the Services we Provide

911Metallurgist Mineral Processing & Process Development Laboratory

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


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