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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Started by BrendonTop
Hi guys, so we are having issues with stibnite at our Biox section since it is exceeding the 3% which the bacteria can handle so now it'smore of a toxin. So we want to pretreat the ore before sending it to the Biox plant. The pretreatment was to be d...
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Last commented on by BrendonTop
Thank you Jorge. Do you have the parameters you used for the Ferric chloride? If you do can you please share.
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Started by BrendonTop
Want to remove stibnite from my ore as it is acting as a toxin at the Biox plant. Leaching using Ferric chloride or sodium sulphide are the options.What are the parameters(pH, residence time,temperature, liquid-solid ratio etc) for leaching antimony ...
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Started by riquecps
Good morning. I am currently working on a project with extremely fine ore, which comes from flotation concentrate. Feed content around 20-50g/t gold, with average tank coal concentration of 100-120mL/L. There is a concentration of around 2-3% of tot...
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Started by Ali Rahim
Hi everyone,  I work in a gold mine and recently, we have started to add a new ore into our blend. As indicated in the testwork, this new ore lime demand is 15% higher than our usual ore blend. Our CIL circuit parameters are - 9.8pH, 250ppm (leach ...
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Started by EAKUVI
Hello Please what are the possible causes of high solid tails
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Last commented on by Samuel Trindade
I think he might be asking about high grade solid tails.
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Started by Michaelmc
Hey guys, been having issues with our elution circuit, we have been having high barren carbon results (150 a 400ppm) from loaded carbons anywhere between 900 - 1300ppm, have exhausted all potential ideas caustic, cyanide, ph, flow rate, temperature...
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Last replied to by Todd H
I would first test the carbon activity both fresh, loaded and eluted. I would then regen some barren carbon in an oven/furnace (lab) and test it again.  I would also examine the acid wash, it is poss...
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Started by ambblanks
Do you have any suggestion on how I can minimize the production of Fine Carbon in CIP-AARL Elution during Gold Extraction? Also, does anyone have any related literature about economical treatment of Fine Carbon instead of just discarding it?
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Last replied to by Todd H
The generation of fine carbon can be caused by a number of issues: Poor carbon quality - too soft, excess fines, too angular Failure to pre-attrit the carbon prior to usage High percent solids in t...
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Started by FeMan
Hello, I have come across people who mix the washing liquid and leachate and people who don't after leaching and before the analysis. Is there any difference between the two in terms of analysis error? Thank you very much in advance. FeMan
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Started by Eng. Cosmas Wambura
Hello, wish you are doing well I need to understand, which chemical I can use to treat zinc-bearing minerals on the gold vat-leaching and how is utilized
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Last replied to by David
Clarify your situation/application please.
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Started by ichigo2785
Hello, I found an old data set for an oxygen uptake rate test for a sample at 45% solids. pH was modified to 10 from 8 using lime addtion, NaCN addition was 0.1% w/v. Air was the gas sparged through and sample was prepared to P80 70um. The test was ...
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Last replied to by Jorge
First and foremost, you have to know the mineralogical composition of the sample because dissolved oxygen is consumed by cyanicides such as realgar, pyrrhotite, arsenopyrite and stibnite. A small frac...
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Started by mohitg
Hi I have a lab scale mixer settler with 2L mixing volume and 6L settlement volume. The mixing time is 5mins and settlement time is 15 mins. Three mixer settlers are connected in concurrent flow.  I am unable to maintain the fixed volume of organi...
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Started by Blackkaiser
*sizing of CIP agitated tanks  *ore is from a dump of 2-3g/t  *I need a complete flowsheet for the design
Last replied to by SmartDog
Start here: https://about.citiprogram.org/course/comprehensive-cip-course-for-advanced-learners/ Depending on your experience level you may need some other sourses. Of course this might be some help...
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186
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Started by Maratib
Please assist! I have powdered ammonium thiosulfate. I need to know how much copper sulfate should be combined with one kilogram of ammonium thiosulfate powder for gold leaching. I appreciate it.
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Last commented on by Maratib
Thanks for the help.
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Started by Maratib
Please help! What will be the chemical reaction if we make a solution of Meta-nitrobenzene sulfonic acid sodium salt and KCN, or NaCN, and dissolve gold into it? Thanks!
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428
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Started by EAKUVI
What causes high Barren eluate
Last replied to by SmartDog
Many things. Process design, process operational upsets, improper chemical addition, wrong chemicals, poor maintenance, bad lab work, water quality changes, bird droppings, people using the process a...
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Started by Sheila reid
Trying to find out the effectiveness of using a tube retort for recovering gold from mercury amalgam.The link below shows an image. Im also having problems finding one to purchase https://imgur.com/a/xEGyR1y
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Last replied to by Jorge
Follow the link below, https://www.911metallurgist.com/blog/mercury-retorting
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Started by Nasirali111
I have gold ore which I finely grinded to powder form. I then added aqua regia in it and let it complete the digestion process. Afterwards I filtered this solution twice to get absolutely clear liquid. I then added caustic soda in excess In it and le...
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Last replied to by Jorge
Follow the links below,
Laboratory Testing & General Mineral Processing Engineering
Gold Refining Process by Aqua Regia
 
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Started by Eng. Cosmas Wambura
Ammonium Nitrate is among of chemicals used to control copper in gold vat leaching, so I wish to know how to use it. The capacity of a single tank is 40t. 
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Last replied to by Jorge
The addition of ammonium in the cyanidation of a gold ore containing soluble copper to reduce the effect of copper has been practiced for many years in some operations. It has been found that the addi...
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Started by ecublens
Hello, there is some arsenic in an oxidized gold ore analysis. It is not in the form of arsenopyrite. I thought it was acting with antimony, but the Sb content is also very low. Could you give an idea what the arsenic here might be acting with?
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Last commented on by Eng. Cosmas Wambura
Can these arsenic minerals affect the recovery of gold?
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Started by GylcineLeacher
Processing of gold/silver tellurides is well documented in operations such as Emperor Mine in Fiji, Kalgoolie in Australia and Cripple Creek in Colorado, USA. Although all of these operations initially utilized roasting, in today’s world it certain...
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Started by Timey
I would like to recover Barium, Scandium, Strontium, Lanthanum, Yttrium, Vanadium from the same ore heap. Please advise on the best process, or help with flowsheet diagrams and materials. Thanks
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Last replied to by Scotman
Hi Timey. Did you manage to come across a process? 
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Started by John KK
In six months, we are going to start getting gold ore from underground mining which is an extension of open-cast mining. There was no metallurgical test conducted on the variability of the ore that is planned to feed to the Process Plant on the assum...
Last replied to by SmartDog
Since you are posting in the hydrometallurgy section an assumption would be that your process is hydrometallurgical, if not what is it? Going frpom that point, a key difference will be ore grade.  M...
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Started by EAKUVI
Does carbon sink in the tanks with increasing densities or decreasing densities 
Last replied to by SmartDog
Normally the tanks are agitated to keep everything in suspension and well mixed. So relative settling is not an issue. If the agitation is stopped, everything will sink with large heavy particles sin...
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Started by Anudari
Hello all, I am working as a metallurgist first time after graduation in Gold processing company. But I have learned that this processing plant has many issues that needs to be solved immediately. Because the plant does not have waste pond or someth...
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Last replied to by Anudari
Update on the topic. I have solved the issue. Just like Jorge said, I had to increase the concentration of HCL and lower calcium amount in the activated carbon. I am not sure what was the most influen...
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Started by WTandC
What would be the expected micron size range of carbon fines in a CIL circuit?  
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Last commented on by WTandC
Thanks Jorge. Would a technology capable of recovering >25 micron size without using chemicals have value in a carbon fines recovery circuit?
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Started by WTandC
I have read the leach emitters can be subject to clogging from recirculating suspended solids. Would removing all suspended solids >1 micron be a significant improvement for the leaching circuit?
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Last commented on by WTandC
Thanks Jorge. My apology for taking so long to reply.
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Started by John KK
Hello everyone We are running CIL tanks with under-designed impellers, and we are struggling to keep the material suspended. To help the agitation we are pumping high airflow through the shaft, but the result is not promising. Does the airflow help ...
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Last replied to by pz
Adimulu, also note that a too high air flow under the agitator could and will lead to the agitator's flooding when air is basically preventing blades from moving the liquid. So increasing the airflow ...
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Started by Rutendo Praise
I have a few tons of china clay, and a sample showed good results, but then the clay is fine and may give me problems processing it. Is heap leaching the best way to have the highest recovery?
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Last commented on by Rutendo Praise
Thank you
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Started by Ajouhi
We operate a CIL plant (8000 t/d), we recover fine carbon after elution and regeneration. I am concerned that the fine carbon recovered after screening the regenerated carbon has a higher grade (1000 ppm) compared to the eluted sterile carbon (100 pp...
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Last replied to by Jorge
It is well known that most of the gold absorbed by activated carbon can be removed during elution. But it is also possible that the carbon has the Ca(Au(CN)2)2 complex present, which can be partially ...
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Started by koki
when harvesting silver from silver cell it looks like semi muddy not solid crystals, what might be possible reasons for this
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Started by Metallurgystudent
Good day to all! Please provide a hand.   What is the most secure way to separate iridium from osmium metal?
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Last commented on by Metallurgystudent
Thanks a lot for your help.
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Started by simon@p
Hello. There is a batch agitation tank that we are operating as a pilot for our ore. The  problem is that we have been getting a problem of inconsistence in carbon results as they may reach example 380 Au ppm then later on with a good recovery fro...
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Last replied to by Jorge
It is important to know the gold extraction from bottle roll tests. Sometimes, tests are not performed correctly and some factors such as the presence of small contents of pre-robbers is not evaluated...
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Started by canerdogan
Hi, How to i know the ore is calcined or not at the roasting stage before heap leach process. 
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Last replied to by Jorge
Roasting is considered a pre-treatment before Carbon-in-Leach Process to treat a refractory gold ore. It is necessary to perform a testing program to determine the effect of particle size (e.g. 70, 50...
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Started by ecublens
Hello, How can we calculate the amount of cyanide (g) that needs to be added after titration in the bottle roll test? 
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Last replied to by Jorge
As you know the volume of leaching solution, you can know the NaCN added initially. For example, NaCN addition 1 g/L, and the volume was 500 mL. In this case you added 0.5 g of NaCN. The titration pr...
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Started by ecublens
Hello, I need a procedure that explains how to do the cyanide column leach test in detail. I would appreciate it if you could share it with me.
Last replied to by SmartDog
A quick search of this site (outside the forum area) will provide most of the test procedures you are looking for, such as https://www.911metallurgist.com/blog/column-leaching-procedure

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