disappearance of gold with pics

[sunnyz1]

Hello everyone,

I created a solution of nitric acid 70% conc with some tap water and poured over a jar of broken up ceramic cpu's. I was hoping to dissolve any base metals but it seems like the cpu pins have gone from pure golden to a kind of faded gold-silvery colour. I tested the solution with stannous chloride and did notice a purple tinge. I am confused as I believed nitric acid cant dissolve gold but it seems to have done so. Why did this happen and how do I go about getting this gold back?

both pics are of cpus after process and solution is now in a separate jar.

Apologies if this has been covered before.

 

[Anonymous]

Normal tap water is treated with Chlorine.

As such it's theoretically possible to make a weak AR solution. If your stannous test confirms this then I'd keep the nitric solution separate and use that nitric later to add to solutions that you need to top up with nitric as AR. Don't throw it away. You won't lose your gold if you use it up as I've suggested.

Since you've been cleaning ceramics it's likely that you should be alright using the nitric in this manner. Dropping the gold from a nitric based solution (as is) is tricky and by the looks of your photos you haven't dissolved too much.

If you are using Nitric to clean product before dissolving gold in Ar I would always use distilled water.

I hope that helps.

 

[Geo]

Covered many times. I will tell a couple of things that will help you to understand. First I would ask that before you do anything else, study the process that you want to do. That way, you will know what to expect. How would you know whether or not something that you are doing is right or wrong? In most countries, the tap water contains chlorine. It's added to the water supply to kill all the organics in the water making it sterile. The chlorine in the water and the nitric acid made a weak solution of aqua regia and dissolving some of your gold. That looks like a sizable investment. You should study the the process that is recommended for this type of material. Cover everything safely and do not try to reclaim the gold from the used solution as you may be able to use it in the dissolution that you should have done in the beginning.

Don't forget to download a copy of Ms.Hoke's book "refining precious metal waste" and read and study. This isn't a request here more than a standing warning. We may answer a few simple questions but it wont take long to attract one of the moderators. It is expected that you use the search feature and refer to Ms. Hoke regularly.

Spaceships beat me to it. :lol:

 

[Anonymous]

Spaceships beat me to it. :lol:

You snooze you lose :lol:

 

[chinto501]

If u cant wait around till u make ar out of your nitric solution u could always chuck in a couple of copper pipes and your gold will return back as a dark sludge. Some on the pipe and some on the bottom of the container. To refine it dissolve in ar. Then neutralise with urea and drop your gold with smb.

 

[FrugalRefiner]

If u cant wait around till u make ar out of your nitric solution u could always chuck in a couple of copper pipes and your gold will return back as a dark sludge. Some on the pipe and some on the bottom of the container. To refine it dissolve in ar. Then neutralise with urea and drop your gold with smb.

chinto,

Welcome to the forum.

Text lingo is not allowed on the forum. We have members from around the world, and some have to use translators to read the posts here. Using "u" instead of "you" can cause confusion.

Use your urea on your yard or garden, not in your recovery and refining activities. There are better ways to neutralize excess nitric than urea, which can create dangerous compounds as well as complicate the recovery of your values.

Dave

 

[patnor1011]

If u cant wait around till u make ar out of your nitric solution u could always chuck in a couple of copper pipes and your gold will return back as a dark sludge. Some on the pipe and some on the bottom of the container. To refine it dissolve in ar. Then neutralise with urea and drop your gold with smb.

No need to contaminate AR with urea. Use only precise amount of nitric what is needed to dissolve gold. Any remaining nitric can be neutralized by including small gold button.

 

[sunnyz1]

Thanks for all the responses and the great advice from some. I guess I better use deionised water from now on so I dont mess up my experiment any further.

 

[rickbb]

Thanks for all the responses and the great advice from some. I guess I better use deionised water from now on so I dont mess up my experiment any further.

Deionized will work, but's it's expensive. Plain distilled is what most people use on gold, (and what was recommended).

This is an example of another of the forum rules, be specific and accurate in what you say. In this case DI, (deionized), verses distilled is harmless, but imagine getting some similarly named chemical mixed up like that.

 

[Claudie]

I use filtered well water. Black Berkey water filters take out anything that will cause you a problem. They cost about $100 a pair but are washable. If you are buying a lot of distilled water, they can pay for themselves over time. Plus you can use them for your drinking water.