what is happening???

[Vicke]

I just dissolved about 40-42 grams of gold in 129 grams of 33% HCl and 29.2 grams of 69% HNO3 at about 50°C and when it stopped reacting and got alittle cold i had about 2 grams left.
I then added 35grams of SMB and it fizzed more then usual ( new batch of HNO3 ).
And then it looked like this and is realy hot and smoking so i took it outside to cool.

 

[Vicke]

It looks like this.

 

[Vicke]

And now after 10 minutes like this

 

[Anonymous]

What did you have 2g of left when it stopped reacting? Also why did you use those specific quantities of acids?

 

[Vicke]

I used thes ratios before and has worked fine but maby the acids was old and now i have new acids.
It has cleared out now and small bubbles is comming up.
The remaining was small nuggets of gold.
I had like 35 grams 95+% the rest 5 -7g was old spill from old batches.
I beleve there was way to much HNO3 and the gold chloride is heavier so it is the orange layer and the top layer was without gold becous SMB only reached it?

 

[Anonymous]

Vicke you need to read more of the threads that explain how to do this. You don't use ratios of acids that are fixed, it depends upon the amount of gold you have to dissolve.

You shouldn't leave gold in the bottom, you honestly do need to study more because all the information really is on here.

Best of luck

Jon

 

[Vicke]

Thanks but yes with ratios i ment ratios of all ingredients not just acids. I always add a little more gold then i manage to dissolve the last time just in case something is varying.
Does it realy get very hot when adding SMB i have never noticed that before, it might raised 30-40°C

 

[solar_plasma]

Could it be possible your weight results were wrong? Maybe the weight was locked?

What does your new nitric look like? Is it fuming or even red?

I am far from having spaceship's experience, but considering all I learned here, I cannot see where a massive excess of nitric could come from.

Did you add the smb in a new way, maybe faster or dry? Did you use it dry before?

 

[solar_plasma]

And when you added smb, what color did the smoke have?

 

[Vicke]

The nitric is fuming but not red.
Accualy i usualy add the SMB dry becous i have so much water in the acids already, this time i tried dissolve it but tewn i just added it with the water undissolved. The gold that i am getting out looks like normal but have not weighted it yet. Its almost dry now so will se son if i got out for all the added SMB or not.

 

[Anonymous]

How much did you dilute the AR by before adding SMB?

 

[Vicke]

Red smoke also that never happens. And after a minute it got so hot it came white smoke.

 

[Vicke]

Maby diluted about 50% as i said i usualy have more water in it so was more consentrated now

 

[Vicke]

Ive got out 21,5 grams of gold from the 35grams SMB

 

[solar_plasma]

If more concentrated acid was used, it would explain the heating, if the reaction with smb is exotherm, which I believe - I would need to have a look at that standard enthalpy of reaction stuff again, to be sure, but I get a headache, if I do now :lol:

Drive off any SO2 and test the solution by stannous chloride.

 

[solar_plasma]

I believe your weight of gold numbers has been wrong (40g). This would make the rest plausible.

 

[Anonymous]

Vicke show us a pic of the solution after the first gold has dropped if you can?

 

[Vicke]

This is when it has cleared up

 

[Anonymous]

I would suggest (although I am open to counter suggestions) that you still have a fair bit of gold in that solution.

 

[Palladium]

Test it with stannous chloride. The red some could mean some whent it solution. What was the source material? That could still be gold in your solution or iron it looks like.