# Gold cathode



## elfixx (Feb 6, 2011)

I just tought you might enjoy a pic from my electrolysis process since there is no other image of such thing on the forum.


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## 4metals (Feb 6, 2011)

Very nice, from the close-up nature of the picture I gather the cathode is quite small. How big is it?


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## lazersteve (Feb 6, 2011)

I'm also interested in the set up you are using. 

Looks like it's all done in small beaker.

The electrolyte looks to be green (copper/iron) or has turned green from the splash on the lip of the beaker and the cathode must be some type of resistant metal from it's appearance. I'm assuming the anode is a high purity gold item, or karat gold.

Will you share the details and a photo of the set up?

Here's a forum photo of one of my anodes from a karat salt cell I was tinkering with a few years ago:

Karat Gold Salt Cell

In my set up I was dissolving the gold into solution, not plating it out (electrowinning) like yours.

Does the gold flake off of the cathode easily?

Steve


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## elfixx (Feb 6, 2011)

The cathode is about 7cm large and 8cm immersed in the electrolite. The electrolite consist of 35g of aqua regia treaded gold disolved in 200ml aqua regia diluted with 100ml HCL and water, it is a rich orange color. The cell container is a 1000ml griffin beaker heated on a coffee maker. The anode is about 99% pure gold from inquartation and AR treatment. The cell is running at 1.8 volt 2 amp. What you are seeing on the picture is around 150g deposited on the titanium foil cathode. And yes the deposit does come off easily, the trick is to apply clear tape on each edge of the cathode and using a flexible cathode like foil make the scraping easier.


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## lazersteve (Feb 6, 2011)

Have you had the purity of the resulting gold checked?

What is the green liquid on the lip of the beaker?

Steve


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## elfixx (Feb 6, 2011)

This picture has been taken this morning so it is not even melted yet, and for the green liquid, it's from the the rod that support the cathode, it is made of stainless and the HCL steam has rusted it a bit, it's not from the electroilte.


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## elfixx (Feb 6, 2011)

And I was wondering does anyone know where I could buy premade anode bag? Each and every fabric I've bought is either too tight, too loose or absorb too much liquid.


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## 4metals (Feb 6, 2011)

These guys make all types and sizes of anode bags and have a large selection of materials.
http://www.anodeproducts.com/


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## Oz (Feb 6, 2011)

Nice project there elfixx!

I was curious as to what gap you are maintaining between your anode and cathode when running at 1.8V and 2 amps. Am I reading correctly that your cathode has 56 square centimeters of surface area submerged and facing your anode? Last but not least, how many square centimeters of anode are you submerging that face the cathode?

I hope I am not asking too many questions but I am just trying to visualize your set-up.

It is nice seeing someone work with this a bit and I am glad you chose to share it. I like the coffee burner idea for heat control.


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## elfixx (Feb 6, 2011)

It's a pleasure to share information with other member, after all this forum got me to where i'm at, you guys teached me everything I know related to precious metal refining, without all of you I would have never ever been able to start this business. The anode and cathode are 3inch appart and the anode about 30 square cm. I am also on the way to get my minting line working, I had dies made, purchased a strong industrial rolling mill and hydraulic press now I'm waiting on a replacment part for my press. Since it has been shipped with UPS it has arrived damaged.... no real suprise. I'll be posting pics as soon as I start minting bullion.


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## Oz (Feb 6, 2011)

elfixx,

This really is a great place isn’t it? Most of what I know of refining I learned here as well and I hope to continue learning. It is great when we are thankful, and the best way of showing that is to give back some.

It sounds as though you are setting up quite the operation there. You are making great progress and I look forward to seeing it all up and running. I wish you great success!


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## skeeter629 (Feb 6, 2011)

Great picture elfixx . I am anxious to see your bullion pics as well.


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## Harold_V (Feb 7, 2011)

elfixx said:


> This picture has been taken this morning so it is not even melted yet, and for the green liquid, it's from the the rod that support the cathode, it is made of stainless and the HCL steam has rusted it a bit, it's not from the electroilte.


If memory serves, silver is the metal of choice for the electrical support system.

Very nice job of parting, elfixx. I got so far as to build a gold cell, including making a mold for anodes and casting several---but never put it in service. The results you have achieved are hand in hand with that which I had been lead to believe. The entire thing is way, way cool. My hat is off to you! Thanks for sharing. 

Harold


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## nickvc (Feb 7, 2011)

Reminds me of the gold that we used to pull from the cells where I was sales manager.
Those cells were capable of doing in excess of 5 kilos a day but took a lot of careful maintenance and tied up volumes of gold in solutions, but it sure did produce high grade gold in volume. If I remember correctly the electrolyte was always the worry and had to be changed to avoid the purity of the gold recovered to suffer. Never tried it myself but used to plate gold from GPC onto fine gold cathodes to avoid refining it and it produced nice quality gold.


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## HAuCl4 (Feb 7, 2011)

Nice crystals!. Last time I saw one of those was more than 20 years ago. I never built a cell of my own though. Hats off!. 8)

Here's a video of one of the biggest ones:

http://www.youtube.com/watch?v=4wwWxSNgI08&feature=related


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## elfixx (Feb 11, 2011)

Molten gold cathode with some silver, enjoy.


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## Oz (Feb 11, 2011)

Nice bars. I am curious though, are you Atlas Refining? If so why did you choose to stamp in LBS instead of troy ounces?


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## lazersteve (Feb 11, 2011)

Beautiful gold. 

The larger silver bars also have a nice shape to them. 

Great work!

Steve


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## elfixx (Feb 12, 2011)

Yes, Atlas Refining is my busines name, actualy the 1lbs wasn't done on purpose, it happened I casted a few bar and this one happened to be 454g.


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## Harold_V (Feb 12, 2011)

elfixx said:


> Yes, Atlas Refining is my busines name, actualy the 1lbs wasn't done on purpose, it happened I casted a few bar and this one happened to be 454g.


A little tip. 
Precious metals are not generally sold by the avoirdupois pound, but the troy ounce. A troy pound is smaller than an avoirdupois pound, while a troy ounce is larger than an avoirdupois ounce. To avoid confusion, it would be wise to not mark anything as weighing in pounds, and to be certain to mark in troy ounces. 

The ingot marked 1 pound would actually be 1.216 troy pounds. 

A troy ounce contains 480 grains, whereas an avoirdupois ounce contains only 437.5 grains. 

If you are weighing in grams, consider that a troy ounce contains 31.10348 grams, not 28.35 (avoirdupois).

Very nice job, both on casting, and marking. 

Harold


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## elfixx (Feb 12, 2011)

Actualy all of what's on the photo is going to be sold to a large refiner, I would not in fact sell precious metal stamped in LBS to customer, I simply stamped this bar because it was looking very nice.


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## Harold_V (Feb 13, 2011)

elfixx said:


> Actualy all of what's on the photo is going to be sold to a large refiner, I would not in fact sell precious metal stamped in LBS to customer, I simply stamped this bar because it was looking very nice.


That makes sense! 8) 

I'm curios how you went about casting the one marked as weighing 1 lb. The surface is exceptional. What was your procedure?

Harold


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## elfixx (Feb 14, 2011)

That was totaly random, I have no idea how it went that nice. I had about 1kg in a graphite crucible heated in a propane furnace, I casted this bar first, maybe the temperature of the graphite mold was just right and the silver had not absorbed much oxygen.


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## HAuCl4 (Feb 15, 2011)

Just curious. Did you measure fineness of the cathode gold?.


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## elfixx (Feb 15, 2011)

As for the fineness something quite special happened today, this morning I went to Xpress gold refining in Toronto to sell the metal pictured on the last image I posted. The guy checked the bar and did a xray analysis it came out 99.57%, I told him it was impossible and he told me I will probably never achieve 99.9 without using electrolytic process... lol , I then spoke with him about different refining process including electrolysis and told him this bar has been refined using electrolysis. He was kind of suprised and wanted to know more about it, I spent at least 15min on the subject before he finaly admited that his xrf spectromter wasnt too accurate and there can be over 0.5% of innacuracy in the result. He finaly paid me for pure gold. And you know whats funny, the employe crunching the number to get the payment settled made numerous mistake and the boss handed me the paper saying "you look like you know what you are talking about, fill it".
I was shocked he just trusted me that much to let me calculate my own payment. Off course he verified the number after, making shure he wasnt going let a million bucks disapear


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## EDI Refining (Feb 15, 2011)

did they re-melt your bar or XRF it as is?


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## lazersteve (Feb 15, 2011)

The last bar I sold XRF'd at 9998 and was processed using poorman's AR at home. With sound electrolytic processes you should be able to do better than four nines in my opinion.

Steve


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## elfixx (Feb 15, 2011)

They did test the bar as is. I guess to obtain a precise result with one of these you must have it well calibrated, have a competent operator and over all of this, the will to obtain a precise result. After all it's all to their advantage to get lower than reality assay.


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## HAuCl4 (Feb 16, 2011)

elfixx said:


> As for the fineness something quite special happened today, this morning I went to Xpress gold refining in Toronto to sell the metal pictured on the last image I posted. The guy checked the bar and did a xray analysis it came out 99.57%, I told him it was impossible and he told me I will probably never achieve 99.9 without using electrolytic process... lol , I then spoke with him about different refining process including electrolysis and told him this bar has been refined using electrolysis. He was kind of suprised and wanted to know more about it, I spent at least 15min on the subject before he finaly admited that his xrf spectromter wasnt too accurate and there can be over 0.5% of innacuracy in the result. He finaly paid me for pure gold. And you know whats funny, the employe crunching the number to get the payment settled made numerous mistake and the boss handed me the paper saying "you look like you know what you are talking about, fill it".
> I was shocked he just trusted me that much to let me calculate my own payment. Off course he verified the number after, making shure he wasnt going let a million bucks disapear



Thanks elfixx. I was expecting a similar story. May I ask what % from spot you settled at?. Amazing how those XRFs knock 5/1000 off, and most people accept it...what is more strange (sarcasm) is that they never read 100.5 % no matter how fine the gold is...


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## elfixx (Feb 16, 2011)

Every single dealer in Toronto are like that, I dealt with 4 different compagny and it's prety much always the same thing and some are even worst. Once I went to bullion stock inc. to get an assay on fine gold, the xrf result was 96%, so I paid for the assay and went to another place where my gold showed at 99.3%... Also the manager at Xpres gold refining told me most of the time the assay if off because they contaminate the sample when they file the bar... quite strange that they are aware using a dirty file will affect the result and they dont do a thing about it... He told me that after he filed one of my silver bar with the same file he used to file my gold bar and the xrf said it was containing 1.5% gold. He didn't wanted to pay 1.5% gold on a 1060g silver bar, that would have been over 650$ for gold that isn't even there.


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## HAuCl4 (Feb 16, 2011)

What strikes me the most is that (this seems like a worldwide phenomenon) most of these buyers' terms are 2-3% discount off spot...but apparently they aren't satisfied with their 2-3% margin...they have to resort to lying and stealing.

In fact it would be in their best interest to have the XRF calibrated properly and read exactly every time. That way they would get a lot of repeat business at 2-3%. Geez if I were them I would have my XRF reading 0.25% too high...and have the customer "happy". :lol:


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## stihl88 (Feb 16, 2011)

I think it was Oz who said, take along a known 24k piece and calibrate their machine with this piece.


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## rbramsey (Feb 16, 2011)

I have not seen a XRF machine. What does the readout look like? Is it something that needs to be interpreted or does it spit out Au 999.9% AG 000.1? Can I stand over the operators shoulders an see the "number" and understand what it means?

Why couldn't you have them test one their pieces of 24k to see how well it shows?

Richard


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## jimdoc (Feb 16, 2011)

rbramsey said:


> I have not seen a XRF machine. What does the readout look like? Is it something that needs to be interpreted or does it spit out Au 999.9% AG 000.1? Can I stand over the operators shoulders an see the "number" and understand what it means?
> 
> Why couldn't you have them test one their pieces of 24k to see how well it shows?
> 
> Richard



You can check out this site;
http://www.niton.com/?sflang=en

Jim


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## Lou (Feb 18, 2011)

Sounds very amateur hour to me if they're using a file. Only time I use a file is if I'm manually checking scrap to see if it's plated or filled.

In reality, you polish the surface and sandblast it ever so lightly. Most important is that you prepare the surface the same way every time.

XRFs come in many different flavours. From the cheapo hand-held ones to the desk top units costing ~$300,000 (w/ service contract). At the top end, they're very good. 
I don't recall if they're yet ASTM approved like fire assay and ICP...


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