Half gold chloride didn't drop gold

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I haven't added any Hcl yet, in my head it seemed like a good idea but I was warned against it as 'experimenting' but to me it made some sense. The solution is about .75l and contains about 40g AU. There's obviously about 100g+ of smb and it's still producing brown vapours. The delivery date on the stannous is 26-29th Aug so this is becoming a massively drawn out thing (I should have ordered it sooner) :|
All I can do is wait for that it. I'll try some Hcl for the second solution and see if that helps the drop.

Edit: It's closer to 1.25l. From other threads I've read would it maybe be worth while concentrating the solution slightly then adding Hcl?

Edit 2: I managed to find a company online and got some Tin (II) Chloride. I'll prepare it later and test the solutions. I'll let you know what I find out,

Thanks guys.

Chris
 
Regarding "experimenting"...
To have good reason to do something, with have an expected outcome, is one thing. Experimenting is when you start thinking "I wonder what would happen if I...". And then it is definitely better to ask before you do something potentially counterproductive.

Everyone who answers is genuinely trying to help you. But you see, you also asked a question about whether you should boil, then later revealed you'd already previously done it anyway. So we're not really sure where you're up to.

Now, adding HCl will cause no harm, but excess does lead to more waste to deal with. You have said you have read Hoke's book. Her evaporation method actually requires adding HCl. She talks about evaporating down excess nitrate, you should find it around page 45 - that's from memory, I don't have it handy but I have spent a bit of time there myself in the past. It's a time consuming process. I used a stripped down coffee maker.

If you have 100g of SMB in there, you'd have to have one heck of a lot of nitric in solution. That's why I thought you could have mixed SMB with sodium nitrate. Don't SNIFF it, obviously, but does your solution have a "smell" of sulphur dioxide / rotten eggs at all?

Concentrating, slowly, gently, will not harm your solution. You've about an ounce and a half (?) of gold in that 1.25 litres of solution. Hoke also says that each ounce of gold you need 4oz HCl + 1oz HN03. So you can safely reduce it by a fair bit.
 
Thanks for all your help guys. The ideas have been invaluable!

I mixed up a batch of stannous chloride and tried it on both pots. The one I thought had dropped was all clear and the yellow pot went black.

I've since cleaned off the gold from solution from the clear pot and started driving off some of the liquid from the other.

Hi Jason, the smell is slightly 'eggy'. When I add the smb which is definitely smb (otherwise the brewery have got it wrong) thee is a small puff of brown and the gold tries to precipitate but is drawn back into solution. I still don't understand why two pots that were divided from the same batch have worked so differently.

As for too much nitric I think I can answer that as a rookie I thought that not all o the gold had dissolved... I've since learned that it was probably rhodium that was on a cross pendant in the batch (it looked like gold, doh)

Chris
 
chrisjames said:
I mixed up a batch of stannous chloride and tried it on both pots. The one I thought had dropped was all clear and the yellow pot went black.
Click to expand...
You did what?! :shock:
Oh man, you really have to read a lot more before doing. What were you expecting to happen?

You test for presence of gold with stannous chloride. Hoke calls it testing solution A. The idea is to use it on a sample of your solution, e.g. a cotton bud. The dissolved tin forces the gold out of solution as a colloid, which looks purple/black. You don't mix it into your solution.
Item 10: http://goldrefiningforum.com/phpBB3/viewtopic.php?t=562
You certainly have a positive reaction.

I think I am unable to help you recover it from here. Adding stannous chloride to the gold has taken it beyond the scope of my pitiful knowledge in breaking colloids.
Depending on how much SnCl2 you have put in, it may be possible and worthwhile trying to redissolve it with sulphuric (a stronger acid), or cutting your losses on a small amount of gold that has become a colloid. Do NOT just blindly add sulfuric acid! Don't do ANYTHING yet.

It now requires someone more expert than I, before you do anything else to your solution.

I expect these things will need to be known:
1: Exactly how much SnCl2 did you mix in?
2: If you take a cotton bud (q-tip) sample of your now black solution, does it still give a reaction for gold, when tested properly with stannous chloride.

As for too much nitric I think I can answer that as a rookie I thought that not all o the gold had dissolved... I've since learned that it was probably rhodium that was on a cross pendant in the batch (it looked like gold, doh)
Click to expand...
As a side note, did you by any chance add your nitric AFTER you divided the jug into two pots?
 
Reading your long post made me panic Jason thinking I had messed up. Don't worry when I say I tested it on both pots I mean used my glass rod to drop a tiny amount onto a glass tile and add a small drop of the stannous. I also used the recipe I got off here which worked great. :lol:

I've only gone as far as heating the solution to draw off some h2o but it's taking its time as I only have a few hours of light after work (plus if I'm in the shed all evening my fiancé isn't too happy!!)

All the additions were done prior to filtration. I finished the reaction of the ar, added a few drops of sulphuric and let settle over night. I then filtered the solution and divided the pots into 2. I then took off a small amount to test with the smb which worked instantly so I used it on pot one which reacted immediately and dropped all of the gold. I immediately put in smb to pot 2 and... Well we know what happened after that.

I've been over the pictures I've taken and there really are no more steps.

Thanks for your concern Jason :)

Chris
 
Way to freak me out Chris. But you did say you tried it on the pots and the yellow pot went black.
Ok, all happy then.

Your process of adding a touch of sulfuric, waiting overnight, then filtering; it looks spot on to me.
 
I think I need to be careful how I phrase things :oops:

I've followed as closely as I can the indeeditdoes YouTube channel. I believe the guy from it is on here. Very informative!!

It's my fault that I messed it up as I added the extra nitric when I saw what I thought was gold not dissolving which I now think was the rhodium!

I'm going to reduce and possibly try hoke's hcl reduction. I'm just having to learn to be patient, which isn't easy! :p

I'll let you know what happens, I was hoping to have the watch cast by my birthday tomorrow but that's never going to happen so at least I can relax about it now.

Kind regards,

Chris
 
Evaporation really does take ages. Rate is somewhat proportional to surface area so do use the widest mouthed container you can find. For me it was only 200ml at a time, so salsa jars were excellent. Your existing pot is probably pretty good. And as your pot gets lower, the surface area will increase. A gentle breeze will speed things up. You want a zephyr, rather than a squall.

This is what I did myself, about a year ago, to avoid cementing. Now, I'd just go with cementing on copper with stannous testing to tell me when it's done.

Your birthday present will be late. But it will come!
 
Thank you, you too palladium (Sorry I don't know your real name) :p

I've just been reading on cementing to make sure I have all the facts. It may just be the way to go if it doesn't drop soon.
Funny you should say about surface area as I was thinking about dividing the solution into my two pots to increase the surface area a bit but we've been here before haven't we! :roll:
I was going to clean up my gold and then do the process with AR again to make sure I have as pure as I can gold to then alloy to 18k rose so when it goes to the assay office I have a better idea that it's 18k and not under.

Jason if I were to cement with copper could I then go straight to my 50/50 nitric followed by AR or would I have to enquart, 50/50 and AR? It isn't a massive issue it just adds a few annoying steps.

regards,

Chris
 
Evaporation takes a long time, heat makes it go faster and so do larger surface area.

But the coffeepots are not a suitable vessel to evaporate from. The narrow neck hinders the moist air from leaving the pot and evaporation slows down to a crawl. You need a wide vessel with a low rim to increase the exchange of air.
Forcing air above the surface also removes the saturated air and replaces it with dry air which easily absorbs new moisture. Guess why we blow on a cup of hot coffee?

So to recap, coffeepots are really bad for evaporation, the narrow neck is designed to minimize evaporation and keep the saturated air inside. You want a wide and low vessel instead and a draft speeds it up even more.

Göran
 
I offer the opinion that coffee pots are less than ideal, rather than unsuitable. By all means a wide mouthed dish is better if you have something handy*, but your existing pot will work if it's all you have. It just takes longer (possibly even much longer). You do at least have a decent surface area going for you.
Droplets may form near the top of the pot and these are testament to the inefficiency of the pot shape. But if you have air flowing, you will also have air currents eddying in the pot, helping you out.

Moving your solution around from vessel to vessel is also less than ideal and should be avoided wherever possible (rather than disallowed). You either leave a tiny bit behind, or you add more water each time you properly flush out the old vessel. Or both.

I can't and won't speak for inquartation processes. But I can tell you that after taking your gold powder out of one acid, you don't want to drop it straight into another. Even after washing in water, residual HCl + nitric = AR = dissolution of gold. You would need to incinerate your powders red hot first when changing between acids. Harold_V has an excellent post on incineration. And washing.

* Don't use kitchen items for refining and expect to use them in the kitchen again.
 
Correct, except when the next step is AR. There is no need for incineration between inquartation and dissolving the remaining gold in aqua regia. The only thing you will see is a small cloud of silver chloride that is formed from the silver nitrate. To wash away all silver chloride is virtually impossible, it will sit inside the gold sponge.

Göran
 
Also, we've covered making Stannous Chloride a million times. Geo has a pretty good video about it. Use HCl and tin solder and you've got your test solution. Geo's video below in case that simple combination is a tad complicated...

https://www.youtube.com/watch?v=659G75Kc3F0

Oh, and coffee pots? Buy some lab glass online it really isn't expensive.
 
Add Cyonide to water, and install to liquid. It will form. Use a gas mask! After gold has formed, it will be a problem with evacuation the of the cyonide and chems.. It will drop.. Mad-
 
In the end I cemented with copper (which turned out to be really easy) I just wish I had done it sooner. I then re dissolved in AR with the rest of my gold precipitate from the other pot and then precipitated the entire thing. I figured it would be purer which it did.

I've now alloyed it with copper and silver to make 18k rose. It's a great colour!! I'm currently in the garden with my homemade kiln and burnout oven trying to cast my watch (that was the purpose of the refining) I'm just doing a practice cast now out of silver to make sure I get it right but I'll hopefully be casting the gold watch in the next day or two. I'll post pictures if anyone's interested?!

Thanks for your help on this guys, I really couldn't have got it done without you all!

Kind regards,

Chris
 
Hello to all,

I came here while doing research and reading the thread and various comments, i have a question for those that have worked with ferrous sulfate.

I have had a solution with excess nitric in the past. Tried to drop with potassium MB. It kept redissolving.

I then did nothing more and switched to adding ferrous sulfate (from a funnel with a filter, so slowly) and did eventually drop.

I'm mentioning it since i think in time it pushed out the excess nitric and someone has mentioned in the thread adding a few drops of sulfuric acid, and ferrous sulfate is produced using sulfuric acid.

So my question is: for a excess nitric solution, would dropping with ferrous sulfate after SMB (or PMB for that matter) failed, bring benefits as pushing out exess nitric and adding benefits in connexion to sulfuric acid (which i don't understand at this point).

Curious to know.
And i look forward to pic of the casting of the watch too

My best to all!
 

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