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CIP Tanks Carbon Addition (5 replies and 1 comment)

Bill Fraser
11 months ago
Bill Fraser 11 months ago

Is it advantageous to have increasing amounts of carbon in each downstream tank in CIP? And what could be the drawbacks? If one looks at CIP as a Rougher-Cleaner type system, you would want a lower amount of carbon in the first tank to get to your target loading capacity (cleaning) with the last tank to do all the work and grab as much as possible (rougher). A smaller amount of carbon in CIP #1 would increase the driving force for gold to adsorb, while a large amount in the final CIP tank would increase the driving force for gold to adsorb as well. Any thoughts?

Victor Bergman
11 months ago
Victor Bergman 11 months ago

Not really Bill, you need to have the same amount of carbon in each cell. Remember the CIP has a solution profile with the feed tank having a high solution grade. So with less carbon in the first tanks will results in high loading but less gold due to less carbon quantity. This will further put pressure on the downstream tanks resulting in loss of gold. It is advisable though to top up carbon on the last tank. This is because the feed tank always have a least carbon activity. Please read literature on factors affecting carbon activity, solution grade and flow rate stand out from the rest.

10 months ago

i agree with you Victor, except in amount of carbon in each cell, normally first tank have high amount of carbon and constant amount at the centre tanks and high amount at last tank in such a way that last and first tank having same amount and if you plot graph of number of tanks against amount of carbon in each tank must show up U shape.

Bill Fraser
11 months ago
Bill Fraser 11 months ago

I like the thought about loading up the last tank. If you could provide me with such references, I would be glad to have a look.

11 months ago
David 11 months ago

The concept sounds interesting and would require significant testing to prove out. The main issue would be how to do it. Since most CIP circuits have the carbon running counter current to the ore with the feed tank being the one producing the loaded carbon, this concept would require recycling carbon back to the same cell. I would think the controls and piping could get complicated.

11 months ago
JohnnyD 11 months ago

In my opinion you would like to move counter currently your carbon as fast the first carbon comes into equilibrium and its loading rates is decreasing. To add more and more carbon concentration down the line will expose the "waiting" carbon to fouling for longer time consequently loosing activity needlessly. I don’t see any real benefits. In addition it will also complicate the carbon management.

David Kano
11 months ago
David Kano 11 months ago

Several reports have been published by esteemed researchers. The best results come from having the carbon profile(g/lit) the same in each tank. I have experimented with this years also and support it. Don't forget that most of the leaching takes place in the first tank where cyanide is added.  It important to grab that gold onto the carbon as fast as possible- always be careful of pregg robbers- a lot of good high activity carbon will then work better.  A lean inventory will load faster, surface area versus dissolved gold in solution. 

The problem is your residence time; you will have higher grade solution passing to the next tank so you put the system under more pressure and risk potential of dissolved losses. Having a small carbon inventory in the head tank takes a lot more time to fill your loaded carbon hopper and time is money- having high carbon inventory on the tail end will have a bigger impact if you have tank overflows also. So Maintain the same carbon profile (g/l) in each tank.  In summary: rule of thumb, keep your gold inventory to the minimum, if you have CIP increase the carbon density to what your first screen can handle and strip as often as possible. 

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