Hydrometallurgy: Leaching in Heap, Vat, CIL, CIP, Merrill–Crowe, SX Solvent Extraction

Hydrometallurgy: Leaching in Heap, Vat, CIL, CIP, Merrill–Crowe, SX Solvent Extraction

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824
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Started by redcastle
I've posted here before about a project I've got that has problems with high clay content requiring large cement addition for percolation. Part of the testwork looked at simply crushing it and agitating in a vessel and it got decent recovery. I was ...
r
Last replied to by rob riggir
Vat leach is really only good for high grade, low throughput -  1 man and a dog type operation.  For the grade and clay you have you should just go for standard agitated leach and activated carbon ...
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740
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Started by oro
I recently built and started up a small CIP plant and came across this simple titration calculation recommended by A K Williams.  The math is simple and I assume the formula is accurate - but would like to confirm.   As follows: 1. make up 1 liter...
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Last replied to by Lazaro
Hello!! I want to know how can I determine if the leaching is complete or not during vat leaching  process of Gold, and if there is a method what are the chemistry behind that process.Thanks
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642
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Started by Dossa
How can i recover gold from refractory gold ore having high content of sulfur by chemical treatment?
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Last replied to by metallurge
The best (environmental friendly and efficient) method would be the roasting process. in the roasting process energy from oxidation can be recovered as steam / electrical power and the sulfur is conve...
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588
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Started by Gabriel
We will start a RIL operation and we will use kerosene to passivate carbonaceous matter. I would like to know if there is any method of kerosene analysis.
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Last replied to by Jorge
You will use kerosene and an ion-exchange resins to adsorb the gold. There are not many operations using a resin process (RIP, RIL or RIS). The advantages of the resin over activated carbon are the be...
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504
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Started by Samuel Trindade
Hello Gents! I've occasionally facing some recovery problems. I've done some diagnostic leaching tests and it seems to have encapsulated gold in sulphide. Crossing a lot of process data I've noticed a subtle relation between increasing in tailing gr...
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Last replied to by Jorge
It is important to know the gold grade reported in tailings. You did not provide that data. Now, considering the fact that you have a refractory gold ore, it is possible that the distribution and cont...
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Started by Paulo V
Hi, I have been doing cyanide leaching test for samples obtained from piles of a material that has been weathered for months.  The recovery achived was from 60-80% for direct leaching of the head and 90-95% for gravimetric concentrates obtained fro...
Last replied to by SmartDog
Sodium hydroxide and or lime
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925
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Started by JdmJeremy
I came across an old operation on government property that appears open to claim (I will verify before removing any minerals). Background: I know nearly nothing about cyanide leach. Here are a few details that I found in mining reports and other do...
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Last replied to by JdmJeremy
Update: I collected some samples from the mining area. There is no visible gold in the ore. However I tossed a few chunks into a fire pit and the next morning there were significant gold color specs. ...
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Started by Graeme
I am looking to conduct a brine leach on a Pb-Zn-minor Ag ore, could someone please give advice/pointers (for eg: what acid to use?).   Thanks
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Last replied to by Jorge
It is possible to perform acid brine leaching tests to evaluate the metallurgical response. The key reagents are sulphuric acid and sodium chloride. For example, the acid sulphuric strength can be 5 g...
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Started by Dossa
how can the ore described below be pre treated in order to achieve high gold recovery using VAT leaching plant? arsenic 9382ppm,sulfur 42679.67ppm and gold 6.26ppm
Last replied to by Miya
find some lab to run the leaching test
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615
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Started by oro
I need to setup an alkaline drip for a 1 t/hr solids feed to a small CIP plant.   What is the most practical method to do this considering the low solubility of hydrated lime?  I was wanting to use a 55 gal plastic drum but realize 400-500 grams ...
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Last replied to by Jorge
Many small scale gold operations in South America are used to add NaOH in the CIL or CIP circuit. You can prepare a solution and add it in different points. 
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Started by Ninontrans
pleasei have a gold ore that has a high copper content 1.52%, Sulphur of 0.12percent, silver of around 102grams per ton, how do I go about recovering the gold in the ore. I tried panning but it was not effective. 
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Last replied to by Ninontrans
Thanks a lot I will check it out 
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692
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Started by WYOMing Prospector
Have read several studies where it is known that citric acid will dissolve 15 of the rare earths into solution.  Question I have is what liquid can I use with the citric acid for solution and then to precipitate them back out what is the best method...
Last replied to by SmartDog
The normal (if there is such a thing with rare earths) is to use gravity and flotation to produce a concentrate, then use a multi stage leaching process to separate the RE's.  The leaching stage is t...
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757
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Started by ManUtd67
Hi, I am looking for operating experiences for controlling and minimizing copper loading on activated carbon in a gold CIP circuit. The project under consideration is still in design phase.  The ore has some copper associated with chalcopyrite whi...
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Last replied to by Reactor
Hello, If you are still in design mode we may be able to help. We have many years of success with in-solution metals and cyanide recovery using membranes. Regards, Bill
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Started by Reactor [closed]
This is the only reference I can find on the benefits of crystallization in mining processes. Are there other mined ores that have crystallization as a part of their process (either to improve recovery or to separate elements)?
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Last replied to by Reactor
Thanks Todd.
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909
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Started by Rahel John [closed]
CIL leaching...to know the amount of cyanide that can be consumed during leaching an ore contain 16% sulfur and less than 5000ppm copper  
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Last replied to by Todd H
Test work will reveal all!  Consumption depends on the mineralogy not the element grades. Regards Todd
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794
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Started by simon@p [closed]
can ammonia be used as an alternative to remove copper from gold loaded carbon instead of cold cyanide wash
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Last replied to by Todd H
Maybe but if you mix the chemcials you are going to have a hard time keeping them separate.  Acid washing prior to elution is the most common method.  Cold cyanide may cause the loss of some gold. ...
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853
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Started by AJ [closed]
Good Morning all, Using a Zadra elution circuit at what temperature does a cold strip become a hot strip and what are the essential differences between the two.
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Last replied to by Todd H
130 degrees C is typical for normal stripping - anything below boiling would be considered a cold strip per se.  This comes down to atmospheric stripping vs pressure stripping really not temperature....
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477
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Started by graeme23miller [closed]
I am trying to source data on the conductivity of copper electrowinning electrolytes: Cu 30 - 50 g/L, H2SO4 150 - 180 g/L & 50 Celsius.
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Last replied to by Todd H
Why?  The baseline EW parameters apply to almost all copper solutions unless there is significant iron or other impurities in it. https://pubs.acs.org/doi/pdf/10.1021/je8001255 https://www.nrcresea...
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709
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Started by ManUtd67 [closed]
Considering a gold processing plant that is processing ore that contains some copper (chalcopyrite).  Copper in the ore is around 300-1000ppm. The flowsheet includes a gravity circuit and so expect the gravity concentrate to also contain elevated c...
Last replied to by Gene Cheeseman
Luckily, chalcopyrite is not very soluble in cyanide and its relatively low SG means it won't be in very high concentrations in the gravity concentrate.   It's the other copper minerals you need to...
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852
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Started by Millza79 [closed]
For a resin-in-leach gold application, is there that if you overdose kerosene addition, you will blind the resin?
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Last commented on by ManUtd67
Unlikely you will blind the resin.
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826
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Started by Wadzanayi [closed]
Hello Process Engineers In a CIL circuit, does pre-aration to increase DO levels, always result in  the benefits of  reduced cyanide consumption improved gold recovery  
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Last replied to by Todd H
Preaeration does not always result in benefits but it will not hurt the process.  Typically it is used when you have high cyanide consumers such as sulfides and the preaeration oxidizes the surfaces ...
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646
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Started by Wadzanayi [closed]
I hope that I find you well.    I would like to know the differences in performance if  any, between Norit and Coconut based hydrocarb activated carbon for adsorption in a CIL circuit. The major issue is the difference in the cost between the t...
Last replied to by SmartDog
Every operation is different and no general answer will be always correct.  The only way to know for sure is to do lab testing or even pilot testing.
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654
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Started by mashafaei [closed]
We have a copper mine, which combines copper sulfur and copper oxide, that copper oxide extracted   using "HEAP LEACH" process . It is now the copper sulfur was remained in the "HEAP LEACH" with a concentration about 1-5%. My questions are:   Is...
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Last replied to by Todd H
If you google bioheap leaching for copper you will find a lot of articles on the subject.  Here is one link https://www.911metallurgist.com/blog/wp-content/uploads/2015/12/Thermophilic-Bioheap-Leach...
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743
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Started by JPExit [closed]
Would there be a significant difference in Carbon Activity results if I use a Hot Plate  rather than an Oven to dry carbon samples prior to Carbon Activity Determination Test?
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Last replied to by Todd H
It should be ok to do this but I would avoid direct heat - place a spacer like a  couple of glass rods between the beaker bottom and the hot plate.  Cover the beaker with a watch glass to allow even...
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710
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Started by CA [closed]
Hello. We operate a small scale leach plant in a region where it is difficult to find hydrated lime for us in pH control.  We tend to only have access to a milled lime ore (artisinal) that comes from local sources. We are dealing with a very acidi...
J
Last replied to by Jorge
You can use sodium hydroxide instead of lime. Many CIL operations add NaOH to get an alkaline pH (10.5-11.0) in the cyanidation circuit.
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658
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Started by Praymore [closed]
What is the best mesh size of activated carbon to use for gold adsorption in a CIL/CIP circuit comparing 6*12 and 8*16 Carbon? Does the mesh size affect the desorption rate of gold?
J
Last replied to by Jorge
There are some problems depending on the ore type. It is important to perform abrasion tests to evaluate the carbon. Follow the link below, https://www.911metallurgist.com/hydrometallurgy/carbon-loss...
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Started by Millza79 [closed]
Hi All,   for determining heap leach recoveries, is this the formula: [(Total PLS flow (m3) * PLS Au (ppm) * Solution SG) - (Total barren liquor flow (m3) * barren liquor Au (ppm) * Solution SG)] / (Total tonnes on heap leach * Head Au gr...
Last commented on by Millza79
Thankyou.
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674
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Started by Millza79 [closed]
Does anyone have any papers or links on the metallurgical accounting for heap leach operations? I.e., where are sampling points (each solution flow, each lift etc), how are recoveries determined etc?
Last replied to by David
Normally heap leach operations develop their own mass/met balance in house (Excel) with the metallurgist or purchase proprietary software such as Metsim, Goldsim, etc.. The key is keeping good record ...
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672
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Started by Edson aman [closed]
In most cases leaching process is done using sodium cyanide due to its high activity while in adsorption the activated carbons work well when there are many  calcium ions in the pulp therefore in other words it seems like not necessary using sodium ...
Last replied to by SmartDog
Cyanide is the general descriptive term applied usually to sodium cyanide (NaCN). However, the early work in cyanidation was based on the use of potassium cyanide and strengths of solution as well as ...
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840
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Started by simon@p [closed]
hellow, I have gold ore which contains high amount of copper.  I have heard that apart from flotation I could use ammonia pre-treatment to reduce the amount of copper in the ore I have bottle rolling test so I'm asking for the procedures to do th...
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Last replied to by tesaygo1
Hello guys, Last year i also tried this process buy haven't get a good result due to insuffiecent equipment, but somehow give me a idea how things suppose to be working.   Since you guys are worki...
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Started by jonas chihoyi [closed]
gentlemen assist me with initial cn and lime additions in a heap leach operation
J
Last replied to by Jorge
The first step is to perform cyanidation tests to evaluate the effect of different parameters on gold extraction. For example, NaCN strength, you can study three levels, 0.5, 1.0 and 2.0 g/l. The pH a...
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761
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Started by Jaime Jacob [closed]
Hello I need to modell a copper column leaching, the movement of solutions inside and the extracction of copper. Any could help me Thanks a lot
Last replied to by SmartDog
Your main title was about heap leaching, while your actual words described column modelling.  These are different things.  That said, to model either one you will need to study Computation Fluid dyn...
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791
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Started by vaheedghassemy [closed]
help please.I need fundamental information  about solvent extraction of copper . i want to design a factory to produce 1000 kg/day copper cathode . cu in PLS is 2.5 gr/lit. please help me. thanks 
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Last commented on by vaheedghassemy
thanks dear for your help.
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812
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Started by Millza79 [closed]
Is there a particle size where agglomeration is NOT required prior to heap leaching? I am reading a testwork report, where the fine fraction (half inch) was  agglomerated, but the coarse size fraction 92 inch) wasn't agglomerated.
Last replied to by SmartDog
A simple answer is that particle size and shape are two important parameters in optimizing heap permeability. Without agglomeration, fines clog spaces between larger ore particles in the ore bed, prev...
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785
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Started by viyana [closed]
hi we have hot filter cake (from zinc plant residuals) and it contains 1-2% Co and 12% manganese, i am going to recover cobalt by solvent extraction with D2EHPA, now, I need some references about design of solvent extraction plant, Is there anyone t...
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Last replied to by viyana
thanks dear Todd i have done tests in lab, we select reduction leaching of cake for Co liberate with acid and H2O2, now i need some information about industrial design of circuits and relation calcul...

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