Pyrometallurgy: Roasting, Smelting, Refining & Electrowinning

Pyrometallurgy: Roasting, Smelting, Refining & Electrowinning 2017-04-21T02:33:06+00:00
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Started by Ahmed Zaky
I have ( gold - lead - silver)  and i ask if it is suitable to make parting for alloy to separate gold from lead and silver by nitric acid instead of cupellation by using bone ash       Thank you
Last commented on by .999
Yes! Lead will dissolve fairly readily in hot weak nitric - 7 parts distilled water and 1 part concentrated nitric acid ( 67-69% ). You can't use strong nitric because lead nitrate crystals will form ...
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Started by jovanifirebird
hi guys. my question is a small scale process. we desorb gold-cyanide (AuCN)) from a carbon. i am currently trying to decompose gold from cyanide in a 1M of NaOH solution. i use stainless steel as a cathode. battery as a power supply. however the pro...
Last replied to by Jorge Ganoza
I would be possible to use a graphite cathode, but you need to select the material and evaluate several designs until get any good result. Steel wool and stainless steel are used because they were tes...
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Started by Ahmed Zaky
Hello  i want to ask  about the efficiency of gold recovery from ash of activated carbon by aqua regia (active carbon loaded with gold from cyanide leaching )  where this ash contains average gold 15 gram per kilo ash   thank you
Last commented on by giom
mr ahmed please do you have any idea how to refine microscopic gold .iuse aqua regia on gold ore and i do precipate with smb a orange brown gold powder but no way i can melt it it fuse to black slage ...
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Started by 2012hegga
Hi. i have a small question i want to know, how many voltage in high pressure elution and current suppose to be?
Last commented on by 2012hegga
Thanx david and about current
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Started by RenniePet
And now for something completely different ...I'm an aspiring author and am writing a thriller based on "the Polish gold train". https://en.wikipedia.org/wiki/Nazi_gold_trainThe heroes (?) of my book have found the train and the gold. They wish to co...
Last replied to by Robert
Consider having them add dopants during melting in order to confound the trail.
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Started by Rudi
Good day fellow mets, Our group is in the process of building a pilot circuit to optimize methods of upgrading a tropical nickel laterite ore using mechanical means (combination of crushing/scrubbing/screening/classification/attritioning) similar to...
Last replied to by Sandeep Bisht
You mean like this? https://www.911metallurgist.com/blog/crushing-grinding-wet-ores
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Started by max skinner
I am running some test using a lab size EMEW cell. I am told to use a certain current density, how do I calculate that? The cathode is 1.5 " diameter by 16" long stainless steel and the anode is 5/8 " diameter by 16 " long titanium.
Last commented on by sarchery
Ibrahima If you don't have a lot of sulphides and have calcined your ore- you can leave out the soda ash. Try as % of concentrate mass: 80% borax, 25% silica and 25% potassium nitrate.
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Started by FTM89
Hi, I`m working on a gold plant as a consultant. I find out that they are using caustic after the elution. For what purpose will they use caustic after the elution? What was explained to me was that it`s for conductivity. What will be a good number i...
Last replied to by David
My friend says his references indicate that cells are operated with electrolyte conductivity in the order of 2 S/m. This is critical if gold is to be deposited efficiently
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Started by geff
why to load carbon with gold and after strip off gold from carbon by electrolysis. is there any research to bypass the carbon loading and directly use the pregnant water as an electrolyte to recover gold ?
Last replied to by Mikhail
In order to send a solution with gold for electrolysis, the concentration of gold should be at least 20 mg / l. Otherwise, the electrolysis process is not justified.This method is implemented in insta...
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Started by biteyaboy
I have cathode mesh which i am going to wash by pressure water and filter solid residues for smelting, also to wash remaining in Wire mesh by nitric acid dry them ready for smelting. During smelting what required reagents are needed and in what quan...
Last replied to by David
Hi Biteyaboy, Be sure to review https://www.911metallurgist.com/blog/gold-smelting-refining-process https://www.911metallurgist.com/gold-refinery/ https://www.911metallurgist.com/gold-silver-refine...
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Started by Alex Loutou
Currently our Merril Crowe running with 2.5 ppm Au, 5 ppm Ag, zinc consumption 5kg/hrs (more than 20x stoichiometry) and 100 ppm PbNO3. So the base metal content in dore consist of 17% zn, 8% Pb and less Cu, Fe. Smelting ratio 1:1 cake: flux (15% sil...
Last replied to by David
I just uploaded this long and extensive history paper. I think it would help you. It reviews an example goldroom refining practices https://www.911metallurgist.com/gold-refinery/ https://www.911metal...
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Started by soheil8
Hello dearsWe have an iron sintering plant. capacity of the plant is 800000 ton per year. Unfortunately, blast furnaces project because of Doing not allow the government exchange and I don't sell the product. Do you have a solution for the profitabil...
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Started by hulk
I need to use my eluate after elution more than once, currently I drain this solution because I think that it is dirty and I prepare another one for the next elution;what parameters of this eluate should i check before use it for a second or third e...
Last replied to by Deano
The only way to find out what effect re-use of your eluate has is to actually re-use it several times and see what effect it has on stripping times and final gold on carbon level. Make sure that the ...
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Started by hulk
During gold elution, a calcium deposit is formed on the plate exchanger surfaces, we perform shutdowns to clean them, can we clean effectively without Disassemble the plates, which cleaner should i use and at which concentration and which depth?
Last replied to by czambrano
I remember to complete with a final step of passivation in order to recover a protective film, but this was for boiler water in calenders, not sure if suitable for Hulk´s application.
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Started by Japhet
Hi Team, I getting trouble to improve fineness on Dore' as most of the time i am getting more  50%+ Ag, Is there a specific flux recipe or extra additive that has been tested to improve the fineness of the gold bars? 
Last commented on by .999
The process David is referring to is called " inquarting " or " quartering." It's when refiners lower the percentage of gold to 25% by the addition of silver or a base metal such as copper. 3 parts si...
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Started by hulk
Hello ! In our gold processing plant we pratice the elution of pregnant carbon by the zadra process, We use two columns: one for acid washing and the other for elution, but the filters in the elution column are clogged very often (probably due to ...
Last replied to by David
Wash the carbon before elution tower or recirculate elution circuit solution clean screens then start strip.
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Started by hulk
hi! how to estimate the required amperage for electrowinning cell for gold(zadra elution process).
Last replied to by Mike Rockandel
Current efficiency is very low, maybe 10%. 700 A will plate about 1 kg/h gold. 
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Started by ely.thar
we conducted a bacisity test on the coal fly ash sample resulting to a ph of 12.01, how can we calculate the volume of our lixiviant needed to add in the sample to reach a ph of 0.8?  thank you for your replies
Last commented on by mikerockandel
Not sure 2stage helps you. But does depend on your objective. Imagine flyash moving left to right and acid solution opposite. 2stage would possibly give you a near neutral aqueous effluent with the f...
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Started by CA
We've been successfully running a small scale alcohol (isopropyl) zadra stripping process for a while now.   We've begun a carbon stripping service for clients and today ran into something we have never seen.  During the electrowinning process, a...
Last replied to by Jorge Ganoza
I think the leaching agent is responsible to form the black deposit on the anodes. The oxidants and electrowinning process can form a black deposit on the stainless steel. There are several secret re...
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638
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Started by Roselyn Yeboah
Please can someone help me with ways to ash gold activated carbon followed by smelting! . I tried ashing 300g using a pot on a gas cooker but we couldn't get the carbon to burn so we tried smelting the granule with borax and salt peter as flux. The s...
Last commented on by Lesley Kupahurasa
For the ashing of carbon you may use Fluidized Bed Incinerators (FBI).
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Started by EcoBlu
In an RDO induction furnace, we are trying a new flux recommended by a friend who is supposedly having success with it.  The ingredients are: 1# Silica, 1# Lime, 1# Soda Ash, 1# Anhydrous Borax, 400g Baking Soda, 4 teaspoons Potassium Nitrate, and 4...
Last replied to by Sugar Watkins
The recipe sounds like baking cookies, pretty bizarre. Too many elements competing with each other. The flux would be suited to reducing an impure iron ore, not much else. Boiling over is likely caus...
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Started by Mikhail
I need a method of burning carbon and smelting to extract the gold. Can anyone suggest a method? What are the potential losses of metal can be?
Last replied to by Mikhail
Hello dear colleagues, thank you for the comments to my question.I'm working on a project to extract gold from the dumps of amalgamation. The technology of heap leaching. Gold-bearing solutions are fe...
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Started by Reidy
Hi, has anybody melted gold concentrate and poured it without using any flux's? Our goal isn't to refine the gold as the mint does that anyway and the cost will be the same. We have low iron and lead levels and I was just curious of anybody having ...
Last commented on by Auexplorer
You might want to take a small sample and try a rock salt and borax mix, It is one of my sampling tactics that rides my assay heat for the same stock. I putter with flux's and it is an old tried and t...
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Started by Amir
  I recycle metal (gold. Silver and palladium) from pcb by hydrometallurgy process. Before i dismantled component  from pcb with  air hummer. But now i decided chemically by  organic solution  like  alkane sulfonic acid and glycol ether  sel...
Last replied to by David
Amir, this may help (not perfectly) ...but have a read to https://www.911metallurgist.com/blog/electrolytic-method-recovery-lead-scrap-batteries page 14 talks on Tin separation of Lead. Fortunately,...
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Started by Colin
Can someone explain the process of extracting gold once you have obtained a concentrate after putting your alluvial material through a gravity machine. We put about 200kg of soil through a gravity machine and ended up with about 2kg of concentrate. W...
Last replied to by Jorge Ganoza
You do not mention the gold recovery. It is important to calculate it to evaluate the metallurgical performance of the gravity circuit. I think you should clean your gravity concentrate using a shaki...
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Started by ameer
Hi, I faced problem in  our pressurise  zadra cell. High voltage appeared 12 volt during gold stripping, ampere was set to 660A, flow rate is 11.5  Temperature is 150 C, anyone can help me to solve this problem
Last replied to by Wayne
Hi,  i would check all your connections in the system, at first glance it sounds like an electrical problem like a partial short causing current to spike, not sure why your voltage would go up though
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Started by sarchery
Is there a specific flux recipe or extra additive that has been tested to improve the fineness of the gold bars that contain high copper content during smelting. The current flux constituents are borax, silica and potassium nitrate
Last replied to by David
Try adding 5% feldspar.
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Started by Charlie
I am having a problem of gold not coming off from the steel knitted mesh in the cathodes in the electro-winning cell. I tried putting the steel knitted mesh in nitric acid before washing it off with a high pressure wap machine but still doesn't co...
Last commented on by Subhash-Kumar-Roy
very inexpensive steel wool=mild steel
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Started by goldinvestor
Hi, I have been invited to invest in a new gold mine (in Scotland) which has just announced preliminary results from a tailings bulk processing trial and I'm trying to get a rough idea of revenues. The Au grade of the tailings is 8g/t (the mine when ...
Last replied to by max skinner
My suggestion, you need a 34 or 64 element ICP to see what is in the concentrates so you know where you stand. The lead concentrates will be the most difficult to get rid of, there are smelters in Mex...
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Started by Madungo
Hello, I need help to releasing gold lock up from my CIL circuit's carbon. I want to run more frequent elution in order to get more gold out but we seem to only recover what we're putting in only. My gold locks up in the tanks and it increases each...
Last replied to by Cyanide
Madungo, Good practice to do monthly gold inventory so you can track circuit inventory and establish good optimum. Most of it is carbon related. Gold on slurry normally only in circuit for 24 hours b...
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Started by Panashe
My Company is involved in toll elution using the pressurized Zadra (350-400kg carbon load), we are now considering using an AARL elution for toll carbon desorption as an upgrade from the pressurized Zadra and the Peter Goossen plants are there any po...
Last replied to by ThabisoKwenane
For water treatment, you can use cat-ionic resins in columns to soften your water. Use brine (NaCL solution) for flushing into your water softener plant. The ultimatum goal is to reduce as much calciu...
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Started by Omurvama
Hi all! I want to smelt an ore with 4 kg/Ton of silver. I have been reading about the process and there are several kind of fluxes can be used. What could you tell me about it? is enough the silver in ore to think in smelting? is the flux selection ...
Last replied to by grant.k.harding
Dear Omar,  The ore has silver worth about $2,500 per ton, so its not worth direct smelting at that concentration, unless you already have the facilities to smelt it. If that’s the case I would ne...
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Started by girishchandra
I want to know about electrorefining of gold to get  higher purity of gold metal. Input of gold would be up to 98% or above . Please help me.
Last replied to by girishchandra
  I am trying to achieve purity of gold about 99.99% Using chlorauric acid for electrorefining.
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Started by CA
We are using the alcohol Zadra method to treat our carbon.  However, due to the origin of the ore we are treating, we wind up with leaves, roots, etc. that catch on the carbon screen i.e. Trash in elution column.  Separating these plant products f...
Last replied to by Bill Fraser
I think you should screen it out from the grinding circuit cyclone overflow. It really is not that hard/complicated. It might cost you $200 to build a trash screen with 1 cm holes in it. https://www....
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Started by kahonde
hello, how does carbon get contaminated with manganese and iron during electrowinning using a single boiler?  
Last replied to by David
It is in your question. You don't know what it is?

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