consolidation of Loss Gold thread

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Yggdrasil

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i have been reading this whole thing for two days now. It still seems a bit off. I am not sure why he even bothered with this? will he have enough incoming metal? he is not LBMA so it is not easy to sell it public, he may still end up selling to a refinery..
I do not think he is UK. He said EU without specifying more, so that may be many places.
 

4metals

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Gold Refinery,
I was looking at the photo and the movie you posted of the gold you dried in the filter and I realized that isn’t the filter you posted to start. The 3 are below. The movie looks to me like a vintage Italimpianti filter. CCEBD2CD-5518-48AA-AB3F-179E4390031C.png 12812946-3B38-44D0-8C43-A55FB07CFD5B.jpeg
The video you sent won’t load from my phone.
 

orvi

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As of UK, I have no idea if Cd is still allowed in jewellery, but I strongly doubt it. Here, it is present only in vintage scrap, and as far as I know, no jeweller nerby use cadmium solder for jewellery - either silver or gold.

And 4metals is right, for that ammount of Cd in the feed, there would be charges in established bigger refineries - so, that is maybe the reason why Gold.refinery is where he is, and doing what he is doing :)
With ammounts he is processing, there is significant interest to do it "on your own", not to pay 1-2% + to the established refiner just for Cd content.
 

Gold.refinery

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Attached is a spreadsheet for you to fill out.
some of the numbers you have posted make no sense such as
Our calculations are posted in the photo. There are several difference.

We lost 2.17 grams in melting and flaking.
In fact, we did not get 9.32 grams. But by calculating the Excel file 7.17 gr.

In addition, we have not yet done copper cementation and also we have not done the recovery of silver chlorides.
 

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Palladium

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This is driving me nuts! I ran the numbers in the beginning of this thread. Maybe somebody else will chime in but are we really doing all this to find $422 out of $125,000? If this is what makes or breaks a multi-million dollar operation then i wouldn't even have started in this business. I understand squeezing a pig til it squeals.... I really do, but this is well within reason for accountability to the customer. The refinery will recover those values later own for it's own benefit. I have to ask, what kind of accountability are you giving to the customer? Are they buying this straight out from the customers? Are they charging a toll? There are so many other numbers missing from these equations.
 

Palladium

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I see it that in chlorides, there will be some grams, after cementing we get maybe gram and that bring us practically to the error margin of the XRF...
From what i understand the whole show is run on XRF and not fire assay. I don't trust them guns that much myself. To me XRF is ballpark. Seen way to may lies from them guns. We haven't even talked about what package the gun is set up for or the calibration. This whole thing could be a wild goose chase of ghost numbers.
 

4metals

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The time spent drying and re-weighing the shot before digestion is only done in production shops for one reason, to make sure all of the metal that left the office went through the melt and shot process and went into the reactor was not missing any metal. In other words to prevent, or guard against, employee theft. Most shops with decent security skip the step entirely.
We lost 2.17 grams in melting and flaking.
This loss is not precious metal, it is typical for lower melting point metals like zinc and in your case cadmium to burn off in the melt process. Those metals are currently evenly dispersed in the atmosphere of whichever country in the EU you are working.

But in your case, since we are looking for grams here, 2.17 x .7564 grams or 1.64 grams of gold was not lost.

Unless you re analyze the shot after flaking and enter the start weight as the weight after sharing the cadmium with your neighborhood, times the new XRF result, you have not taken the fact that only non precious metals volatilize. That 2.17 grams should not enter the calculus. Just enter the start weight before making shot and your starting assay figure.
 

jphayesjr

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This is one of the smaller tumbler plants I have ever been involved with. This one has a capacity of about 6kg of karat scrap.

The reason I am showing these is because they all operate on the same principle as the plant we are discussing here, albeit from a different manufacturer. By seeing different systems we can gain a broader perspective.

Since this system is more compact it is easier to see the condenser and its location, and the filter under the reactor where the loaded solutions are filtered before being pumped to the precipitation tank. All very similar to the OP’s system.


View attachment 50214
Ingenious technology. Recent news may describe a new technology that may simplify processes for us...https://newatlas.com/technology/graphene-recovers-gold-waste-electronics/?utm_source=New+Atlas+Subscribers&utm_campaign=0408f18f6f-EMAIL_CAMPAIGN_2022_08_22_01_48&utm_medium=email&utm_term=0_65b67362bd-0408f18f6f-91743941
 

PREMUG

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i have the same issue in commercial refining. For eg. We get individual dore gold bar lots .We accumulate and say we put in refining say 35,500gms we take dip sample for the same .This done in tandem by taking a dip sample for the individual scrap bars. So assaying is done on the general lot just before refining and individual scrap bars .After refining we separate the silver and get the unreacted popcorns. But nowadays even after taking out powder from the left over solution after precipitation. We still encounter losses to the tune of more than 0.5/kg of popcorn .we can lose more than say 17 Gms in this case. Can anyone put light on this phenomenon.?
 

Yggdrasil

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i have the same issue in commercial refining. For eg. We get individual dore gold bar lots .We accumulate and say we put in refining say 35,500gms we take dip sample for the same .This done in tandem by taking a dip sample for the individual scrap bars. So assaying is done on the general lot just before refining and individual scrap bars .After refining we separate the silver and get the unreacted popcorns. But nowadays even after taking out powder from the left over solution after precipitation. We still encounter losses to the tune of more than 0.5/kg of popcorn .we can lose more than say 17 Gms in this case. Can anyone put light on this phenomenon.?
Not very easy to say as you have not said anything about the actual process equipment and so on.
As you have seen in this thread minor changes to the equipment setup or flow can result in increased or decreased loss.
And another thing is that some may not be actual loss as it can be reclaimed later.
Have you read this whole thread in detail?
 

4metals

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Are you saying from a lot of 35,500 grams you have 500 grams of undissolved material? Or is that an accumulation of the insolubles from multiple lots? As Yggdrasil said, what type of equipment are you digesting in?

Your issue is undoubtedly Silver Chloride but from your preliminary numbers your recovery is very good.

There is much to talk about, such as assaying and spreads in your results and starting Silver content in the dorè. Too much for typing with my thumbs on a phone.

Answer my basic questions and I will follow up in detail.
 
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