Guidance with first time gold drop

[Quiklearner]

Greetings Forum Members!

First of all, I would like to extend a most sincere thank you to all of you who share your knowledge so freely and to those who ask the questions I don't even know to ask yet.

I am asking for your input to verify my train of thought before I try and perform my first gold drop. I have been recovering the gold from e-waste over the last 2 years and after much labour, I have 2 separate solutions of AR saved up. In the picture attached, I will call the small beaker Solution A and the larger beaker Solution B.



Solution A (~50ml): Denoxed by way of evaporation to syrup and reconstitution with HCl and I believe it to be relatively pure. I am estimating to be a little less than 2g of gold in this solution. A stannous test results in a jet black stain.

Solution B (~250ml): Almost certainly contains an excess of nitric acid and is contaminated with what I suspect to be copper. I estimate that there is around 7g of gold in this solution. A stannous test test results in a jet black stain.

BOTH solutions: Crystal clear with no sediment at the bottom.

This is how I am thinking to proceed:

1) Drop the gold from Solution A using SMB.
2) Wash the precipitant with distilled water until no acid remains.
3) Add this gold to Solution B to consume the excess nitric I suspect is present in it.
4) Add (~1ml) sulphuric acid to remove any lead (which I have not done yet as I JUST obtained some).
5) IF NEEDED, add small doses of nitric to dissolve any remaining gold that is left at the bottom. (I will aim to leave a tiny amount undissolved to prevent overshooting and having an excess)
6) Cool the resulting solution and precipitate the gold with SMB.

To remove the remaining base metal contamination, should I collect and wash the gold mud with distilled water until it is acid free and then treat it in hot dilute nitric before I re-refine it in AR one last time?

I don't have any sulfamic acid at the moment, but I have plenty of Nitric, HCl, Sulphuric acids, and SMB on hand.

Looking forward to your responses!

 

[g_axelsson]

One obvious mistake I see in your list is

4) Add (~1ml) sulphuric acid to remove any lead (which I have not done yet as I JUST obtained some)

Lead is removed as insoluble lead sulfate and you need to filter the solution before dropping the gold.

Göran

 

[Quiklearner]

HI Göran,

Thank you for responding. I will be sure to filter the lead sulphate.

Thank you

 

[Geo]

Why add the solutions together? Drop them separately. It seems to just add extra steps. Drop, rinse and if you don't like the color, then add the two together and redissolve. If either of your solutions gives you problems, it will effect both drops. Dropping the two independently avoids this and cuts out a step.

 

[Quiklearner]

Hi Geo,

I wasn't planning on combining the solutions together, I was going to use the dropped gold from one solution to consume the excess nitric in the other as I do not have any sulfamic acid. That was really the only reason I was considering this course of action.

 

[MGH]

Different opinion here. I was actually going to SUGGEST combining both solutions together. I see it as a matter of personal preference, mainly depending on whether or not you want to know how much gold was in each solution. I don't see anything there that would indicate potential issues with dropping the gold, aside from the excess nitric you mention. If the yield per solution doesn't matter to you, then de-noxxing with sulfamic is so easy, combining the solution saves steps.

You mentioned you don't have any sulfamic acid. In the US it can be bought in pure form as tile grout cleaner from Home Depot (about $8 per pound). If you really can't find something similar in Canada, then maybe you are relegated to your original plan, which otherwise sounds reasonable to me.

 

[Quiklearner]

Hi MGH,

Home Depot Canada sells “Tilelab” Sulfamic Acid Cleaner in a 1lb tub for $11. Looking at the SDS, it states 60-100% purity, but does not list what else may be in it. Would there a risk of using such a product? My lack of experience causes me to immediately foresee a filtration nightmare, or worse. Lol.

Thank you for your response!

 

[Quiklearner]

MGH, one more thing...

I’m not very much concerned at this point with the yields from the individual solutions as I am the final. I’m not doing this for profit at this point. My end game is to collect enough final product to make wedding bands for my best half and I. Certainly not economical when all things are considered, but if nothing else, I’m 3/4 setup for a hobby I enjoy and will have a good story for my kids to tell theirs when I am long gone. Who knows, maybe the rings will have even more meaning to them when they gets passed to them...

 

[MGH]

Well looks like I made an assumption here. The sulfamic acid I purchase, Aqua Mix brand - of which I have used several different lots over the years - also states 60-100% purity. I compared the SDS for both brands below. Note the range, the asterisk, and the explanation. I'm fairly sure this is an extremely conservative CYA on the part of the sulfamic acid manufacturer (probably the same party in both cases), and that the purity is actually very close to 100% in general.

In short, I don't foresee any issue using what you have available there. Best of luck making the rings. That's something I'd like to try someday.

 

[Quiklearner]

Amazing! Thanks again MGH, I will get some tonight and give it a try.

 

[Quiklearner]

Hello Forum Members,

Sorry I haven't updated this thread. Work and family have kept me very busy over the last 6 months. With temperatures dropping, I have wrapped up my recovery/refining for the year. For me, 2021 has produced 24.1 grams of 24k gold. By the time I alloy it, I should have enough to make my rings.



I still have some material in my stock pot and a collection of filters that needs dealing with, but that will have to wait until spring.

I wish to thank all of you again. This forum is a wealth of knowledge and I appreciate all of you.

Cheers from Ontario, Canada,

Mike

 

[butcher]

Nice looking gold Mike, bet it is going to make a beautiful ring.

 

[Alabama938]

What kind of alloy are you going to make… 24 g should make some pretty big rings. Great color, NICE

 

[Quiklearner]

To be honest Alabama, I'm not really sure yet... That will be the next chapter in this saga.

First, I will have to learn how to do lost PLA casting so that I can use my 3D printer to model the ring blanks. I am learning most of this as I go.

I come from an Electronics Engineering background, so I know where the gold is in components. At the onset of this project, that was about all I knew.

In April 2020, I build my own Birkeland-Eyde reactor that ran 24/7 for almost a full year to produce more nitric acid than I think I will ever need. While that was running, I slowly started mechanically concentrating the gold from the e-waste I had accumulated. Recovery/refining followed that and now I am going to spend the winter months reading and educating myself on how to melt, alloy, make a mold, and pour the castings. I really wish I knew a Goldsmith!

It has been a lot of fun thus far. Electronics and Chemistry... it's all about the electrons. It always fascinated me that we are able to control and manipulate something that is impossible to see.

 

[bexs987]

MGH, one more thing...

I’m not very much concerned at this point with the yields from the individual solutions as I am the final. I’m not doing this for profit at this point. My end game is to collect enough final product to make wedding bands for my best half and I. Certainly not economical when all things are considered, but if nothing else, I’m 3/4 setup for a hobby I enjoy and will have a good story for my kids to tell theirs when I am long gone. Who knows, maybe the rings will have even more meaning to them when they gets passed to them...

Here’s the rings my husband made us from gold recovered from E-waste. The kids want one each now! Good luck

 

[FrugalRefiner]

Nice first post Bexs! I'd love to hear the story behind those rings.

Dave

 

[Quiklearner]

Great rings bexs! I've been looking into jewelry making workshops in Toronto. Very anxious to get working on them.

 

[bexs987]

FrugalRefiner
The gold was recovered from RAM fingers using the AP method. The larger ring is just over 15g gold, and the smaller one is 10g. They have been refined once, so probably not 99.9. We'll know once we get them assayed.

Quicklearner
We initially approached jewellers to make the rings, but the cost was high, and they were reluctant to use just gold and wanted to alloy with other metals. We looked at courses locally, but there was no availability until later in the year. So a few YouTube videos later and a jewellery making starter kit, we have these beautiful rings. Please share pictures once you get yours done. Good luck

 

[Quiklearner]

bexs: I think I am going to end up going down a similar road. Seems like something that one can easily do with minimal specialty tools. I have a mandrel and a hammer so far!

 

[bp9692]

Hi Geo,

I wasn't planning on combining the solutions together, I was going to use the dropped gold from one solution to consume the excess nitric in the other as I do not have any sulfamic acid. That was really the only reason I was considering this course of action.

I like this idea, I would think if you have any excess nitric acid left over it would react and use it up. makes sense to me.