AR turned brown after adding SMB

[TroyTempest]

Hello everyone, I have a problem.

I'm sorry that my first post is asking for advice rather than giving but I hope that will change in time.

Here's what I did on my way to my brown solution problem.

1. Acquired a lump of melted pins etc that should contain some gold.
2. Swotted HOKE and the forum to get me started.
3. Dissolved the lump using NHO3. The solution was very blue and took some time but ended up with a dark brown/black sludge at the bottom.
4. Dissolved the sludge in AR which went a nice deep yellow.
5. Reduced the solution twice over heat adding HCL as indicated by HOKE.
6. Diluted with distilled water and then tested with Stannous. Please see pics.
7. Added SMB. The solution cleared briefly and then browner than a freshly dug trench.See pic also.
I didn't any other reaction when I added the SMB.

I would very much appreciate any pointers as to what to do.

 

[Geo]

double check your SMB. is it sodium metabisulfite? is it stump-out? your source of the first metal to work with was a poor choice.at the most 0.01% gold by weight and at the least 0.0% of gold.either way, a waste of chemicals. you didnt acquire this lump from Ebay, did you?you would have had better results buying some known material from one of our members.

 

[lazersteve]

Place the beaker with the solution containing the brown stuff and the SMB in a pyrocream dish. Heat the pyrocream dish with the beaker in it on medium heat. If gold is present and you used good SMB, it should agglomerate and settle within 30-45 minutes.

Steve

 

[TroyTempest]

It is metabisulfite. eBay it was - you live and learn. I'm going to have a go at inquarting a couple 9ct scrap rings to keep my learning up.

I wouldn't mind knowing why it went brown though if anyone has any ideas, so I can add it to my knowledge base as it were.

Thanks for your reply.

 

[TroyTempest]

Steve, thank you. I'll give it a try and post the results.

Adam

 

[samuel-a]

Seems like normal SMB precipitation to me...
Dilute (and a bit dirty) solutions takes some time to settle... As Steve said, heat will help it agglomorate... or just let it sit for the night.

Let us know the color of the supernatant after settling.

 

[TroyTempest]

Hello again,

OK, Please see attached pics of the supernatant after settling and after filtering ( of sorts ).


After drying the settled brown sludge it turned out to be mostly water and left very little solid. Pretty much immeasurable as it turned out.
I went to the bitter end and blasted it with my MAPP gas torch. It really wasn't interested in melting. Pic attached also.

By contrast, that torch had no trouble inquarting 9k and sterling,the subject of my next and fully controlled refining exercise.
I'm aware the melting point is slightly lower. I tried copper as well just to complete my temperature test.

Note to self. Don't ever try to refine something when you have no real idea what the source material is. In this case, a lump of rubbish
bought on eBay.

My next project SHOULD produce just over 1g of gold. If anyone is interested I'll post my results.

This is a fantastic forum BTW.

 

[butcher]

TroyTempest,

All of this coming from a lump of pins bought off the internet is no surprise as you most likely had an alloy of brass copper tin iron and other metals and very little gold.

From the start of this project you were up against a very big challenge to get that tiny bit of gold out of the lump of melted mess, the first beaker looked like a strange colored mess with colloids and several metals in solution, but when I seen you had the yellow flask I was surprised as it did look like a clean gold solution (although I have seen iron in a yellow solution that can fool you), Did you filter the yellow solution from the orange red first beaker? If so how did it filter slow? Did you save filters? If so I would save them for the incineration batch later, the last pictures of purple color looked like gold colloids one big stannous chloride test of colloidal gold, at that point I think I would have evaporated the violet colored solutions to dry powder and incinerated, then giving it a boil in HCl and several boiling water washes to try and get the bit of gold which may have gave that violet color.

Can I suggest something?
I think you have been studying hard, continue this, this time following Hokes book, get some good material to work with, get some karat gold and sterling silver, If you have not done the getting acquainted tests in Hokes book do these first to get a better understanding.

In quarter the gold and sterling silver, shot, part with nitric acid, recover the silver, refine gold, this will give you a material of much higher quality to work with, and a better understanding of what to expect.

If you do your home work this, it will be much easier to work with, giving you a better Idea of what to expect in your work as you will be working with a better material, with less troublesome metals, and all of those problems that can come from electronic scrap, recovering the silver and gold from this, and then refining the gold will be easier than messing with electronic scrap, you will get your investment of gold and silver back, and it will help you learn more of what to expect when you do begin to work with the more troublesome materials.

Spend some time studying and planning the project, studying things like how much, how much gold to silver to in-quarter together, how much water and nitric to part silver and gold, how much nitric and HCl you could need to dissolve the gold, and how to add as little as possible of HNO3 to dissolve gold as needed, so you will not have excess to remove later, How to eliminate free nitric before trying to precipitate gold, study and plan out what you need to do this experiment, so it will run smooth when it is performed.

Maybe even post your plan with details so others here can give Ideas How to change things in your plan, starting a thread on this experiment a show and tell of recovery and refining getting tips before making the next steps.

 

[TroyTempest]

Hi bucher,

Thanks for your input and very good advice.

Just to let you know that the brown solution was the result I got after adding SMB to the yellow ( Auric Chloride - yeah right ) solution in the conical flask.
There was just a hint of magnetism in the original lump which backs up your comments about steel.
When it did settle and I evaporated it, there was very little material left. Half a teaspoon maybe and what ever it was it was not gold.
It just would not melt.
I am planning a properly controlled test next which will be a 3.3g 9k ring that I will inquart correctly and follow yours, the forums and Hoke's
methods and advice.
I'll post those results also under a new thread in the Help Wanted section if anyone is interested.
Thanks again

See you

 

[tek4g63]

The stuff in your melting dish does look to be at least some gold, not much but some. It just appears to be very impure. That would account for the bad melt. Also you will find that metal powders, even gold are more difficult to get to start melting. I think its because the powder doesn't hold the heat like a solid button, or ring would. Once you get it melted it is very easy to keep that way, or even to remelt.

Maybe you should get that junk out of your dish and set it aside to re process later after you have practiced with the easier stuff. No since in throwing it away until your 100% sure that there is no gold.