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How to improve copper & gold recovery to copper concentr ... (6 replies and 3 comments)

5 days ago
Saddam 5 days ago

I have been given a project on optimization of copper concentrate grade so as to improve copper and gold recovery. I need help on the main factors which I have to consider in my project. The targeted copper concentrate grade at the plant is 18- 20%Cu, but currently the target is not achieved. The plant ore is chalcopyrite.


Marshal Meru
5 days ago
Marshal Meru 5 days ago

What is your head grade %Cu %Fe Au g/t and other elements you have? What is your primary grind P80?

What are your tailings assay?  Can you post a flowsheet here? Have you done any tests? Can you post the results/conditions here? 

4 days ago

head grade of Cu is 2%, Au is 1.54g/t, primary grind is 125microns , tailings assay is 0.04%Cu. I haven't done any test I am still preparing the scope of my project.

5 days ago
AJNeale 5 days ago
2 likes by Marshal Meru and David

It sounds like you need to go back to the basics and determine a grind-recovery curve and a grade-recovery curve, all of which can be done fairly quickly in the lab.  Run three lab flotation tests at different grind targets to quantify the sensitivity to grind.  Once you think you have determined the "best" grind, then do the same with reagents, primarily collector and pH (lime), usually the impact of frother cannot be measured in the lab, i.e. as long as you have enough froth to float, then you can't do much better than that.

My guess is that the problem is pyrite, and guys have spent their lives trying to develop an ultimate pyrite depression scheme.  Sometimes cyanide works, and sometimes it doesn't.  Sometimes some highly specific copper collector works, sometimes it doesn't.  Sometimes using shorter chain xanthates works, sometimes it doesn't.

The key is to get back to basics - determine the best grind (remember this is a balance between recovery and grinding horsepower), and the best combination of reagents in the lab.  As part of the program you should take a sample of your rougher concentrate and look at it under a microscope - if there is a lot of pyrite is it liberated or associated with the copper minerals.  If it is the former then there are opportunities to optimize flotation.  If it is the latter then you need to look at finer grinding.

I'm sure there are dozen of other things to consider, and the 911 met team can help, but don't make flotation any more complicated than it needs to be.  I hope this helps.

Best Regards


4 days ago

Thanks very much Mr. Andrew. It has helped me.

Paul Morrow
4 days ago
Paul Morrow 4 days ago


seriously: 0.04% Cu tails on a 2% head? You wonder why the low 18- 20%Cu?

What reagent suite are you using (dosages)?

What is you Au/gold content in tailings?  Please describe your flowsheet. Plant tonnage? Regrind? Give us details if you really want help.

4 days ago
Saddam 4 days ago

The flows sheet of the plant has been attached. 

Marshal Meru
4 days ago
Marshal Meru 4 days ago

Hello Saddam, yes please give use details. It appears you are pulling much too hard. We need to know how you are doing it. What chemicals, dosages, % mass pull rate, plant details. The more info you give us, the better we can guide you.

Do you have photos of the plant froth? Videos?

3 days ago

the chemicals used at the plant are PAX, Aerophine and frother with dosage rate of 500ml/min, 80ml/min and 100ml/min respectively. The plant tonnage is 1635t/h, Regrind P80 is 38microns. currently I don't have photos and videos of the froth

Bill Fraser
3 days ago
Bill Fraser 3 days ago

What frother?  MIBC, Dow, Pine Oil? Glycol?

What pHs are you running at? 

What is you Au/gold content in tailings?  

Your PAX, what strength are you mixing it at 10, 15 or 20%?

500 ml/min: are you certain?

What is the %Fe in your copper conc?

Your reagent dosages do not make sense to me...

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