# what is happening???



## Vicke (Jul 10, 2014)

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.


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## Vicke (Jul 10, 2014)

It looks like this.


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## Vicke (Jul 10, 2014)

And now after 10 minutes like this


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## Anonymous (Jul 10, 2014)

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


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## Vicke (Jul 10, 2014)

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?


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## Anonymous (Jul 10, 2014)

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


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## Vicke (Jul 10, 2014)

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


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## solar_plasma (Jul 10, 2014)

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?


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## solar_plasma (Jul 10, 2014)

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


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## Vicke (Jul 10, 2014)

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.


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## Anonymous (Jul 10, 2014)

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


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## Vicke (Jul 10, 2014)

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


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## Vicke (Jul 10, 2014)

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


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## Vicke (Jul 10, 2014)

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


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## solar_plasma (Jul 10, 2014)

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.


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## solar_plasma (Jul 10, 2014)

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


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## Anonymous (Jul 10, 2014)

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


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## Vicke (Jul 10, 2014)

This is when it has cleared up


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## Anonymous (Jul 10, 2014)

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


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## Palladium (Jul 10, 2014)

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.


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## rickbb (Jul 10, 2014)

Having small bits of gold left when the digestion reaction stops indicates that the nitric acid was used up and not enough left to finish off all the gold. Just add a small amount more to dissolve the leftover gold. The act of dissolving gold uses up the nitric. The goal is to use only the amount of nitric that you need for the amount of gold you want to dissolve. In this case you were just a bit shy of that goal.

This is what's meant when others have suggested you read up and study some more. It seems that even though you have had some successes, you, (as I do too), still need more knowledge of the process steps and what it means when you get some unexpected activity.

And, please, don't take it outside when you get heat and fumes, start and keep it outside. Please. The white smoke could have been just water vapor, but maybe not.


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## solar_plasma (Jul 10, 2014)

He had intentionally 2g left! Boys... :lol: , I think, Vicke has not done anything definitely wrong. He had just a strange observation and asked for possible explanations. And I am with Jon, there are good chances, there's more gold in solution, still or redissolved. That's why I said, drive off SO2 and stannous test it.


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## solar_plasma (Jul 10, 2014)

I have a theory....you used a more concentrated acid, which was hot, you added all smb in one portion.... yap, like Jon already said: add in small increments! Under the hot exotherm reaction most of your SO2 was gone before it could reduce any gold. That is why you only precipitated 22g gold. There is more gold in solution.


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## solar_plasma (Jul 10, 2014)

By the way, you need some excess HCl to convert the smb. If your stannous test is positive and if you add more smb, you could need more HCl ...just a thought.


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## solar_plasma (Jul 10, 2014)

And my last advice... I would let it sit overnight, now, maybe the rest will precipitate by itself.


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## bswartzwelder (Jul 13, 2014)

Where were you doing this that you had to take it outdoors to cool? This is not normally a reaction you do indoors.

Listen to the sage advice given. First, test with stannous chloride to be certain all the gold dropped. If it hasn't, you need to precipitate what is left in solution. Second, when making AR, I believe the accepted process is to measure out what you think you will need, and then add it in small increment until all the gold disappears. Then you add the SMB in small increments until it stops reacting. 

TEST, TEST, TEST. Without testing your solution at every step, you really don't know what you have.


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## Harold_V (Jul 13, 2014)

bswartzwelder said:


> TEST, TEST, TEST. Without testing your solution at every step, you really don't know what you have.


Don't you find it rather strange that many readers don't seem to understand this simple concept?

Harold


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## bswartzwelder (Jul 14, 2014)

I had to learn the value of testing. Sometimes it was the hard way and cost me. I learned that lesson and it cannot be stressed enough.

A little off topic, but I mixed up stannous chloride test solution over a year ago. I added stannous chloride crystals with HCl and a little water. Put the solution in a brown bottle with a dropper and keep it in the fridge. A week ago I took it out and put a Q-tip in my gold chloride solution and dropped 1 drop of the stannous onto it. The Q-tip turned black indicating the stannous was still working. Only my wife and I here at home and the grand kids aren't tall enough to reach it. It is well marked.


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## rickbb (Jul 14, 2014)

I keep mine in one of those small dorm room fridges in the shop. Not comfortable with it in the food fridge in the kitchen. Although many kitchen products are just as dangerous I suppose.


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## Vicke (Jul 15, 2014)

I had to take it out becous i had it in my lab so i never do stuffs like this close to my house.
I have no test solution bevous i not want to keep it in my fridge but i will get someting i can store in my lab.
Ive got out everything and it seems like i had iron in it, i am using some sort of steel tols for handling stuffs in acids and i have no idea of the material but it only builds up a thin layer of something black on it when used in strong acids then i just wash it and looks new again.
I beleve thats where the iron comes from.


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## g_axelsson (Jul 15, 2014)

If you are using steel tools in acids where you have dissolved gold or other precious metals the black could be gold cementing out on the steel.

Use glass stirring rods or plastic tools to not add contaminants to your gold.

Göran


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