need a help

[ekrem duran]

first aff all l want to thanks who creates this forum and whom help the other one.
and apologieze for my english.

l wached some youtube videos and try to recovery gold from my old trlrphones and computer parts.
Everything was normal until I filtered my gold plating and melted it with aqua regia.
the solutions color turned green l added sodium metabisulfite the reaction occurs and the color turns black, but my gold does not settle to the bottom. its color turns green again

 

[domus1212]

I think you need to add smb in small portions until all the gold precipitated

 

[Martijn]

Hi Ekrem, welcome to the forum.
How much nitic did you use on how much gold in the AR?
The green color is probably copper.
SMB also drops copper and that is black. It redissolves because of free nitric i guess.
Dissolve some more foils in it until no more gold dissolves.
Or cement the pm's out on copper.
Did you test with stannous?

Martijn.

 

[ekrem duran]

I used approximately 100 ml AR and five filter paper full of gold
l used 3/1 nitric for AR and waiting for 15 minutes and I warmed it up before using it. I washed the papers in water, the solution increased a little. Boiled 4/3 fame and ading smb but not work .
l did not test with stannous or cemment because l dont know much about it.

 

[Martijn]

Ekrem, cementing is simply putting a piece of clean copper in the solution> all less reactive metals will be cemented out. Which are silver, mercury, gold and the Platinum group metals (PGM's).

Stannous chloride is tin dissolved in HCL.
Put a drop of your solution on a filter paper or a spot plate, and add one drop of stannous. Copper gives a brown stain, gold gives a purple stain. PGM's give other colors.
If the stain is too dark to see, add a drop of water to the test paper.

If you have dissolved visible known gold, no need to test for gold in solution when the visible gold is dissolved and no brown powder has formed (cemented gold)
You need to test for gold in solution if your'e not sure if any gold is in the sample, or testing after dropping with SMB or Copperas.

Martijn.

 

[Yggdrasil]

Way to much nitric.
You did not say how many grams of gold it was.
My guesstimate is about 10 times too much nitric,
depending on concentration.
You will have to denox somehow.
Sulfamic or evaporation.

 

[ekrem duran]

Martijn, Thanks for all your help l will make stannous and cemment then write the result.

 

[Martijn]

While cementing, it's likely that some copper and cemented gold will dissolve again due to excess nitric.
Give it some time or keep the solution to dissolve more gold foils.
Next time, barely cover the foils in HCL and only add small amounts of nitric and watch the reaction. Add when bubbles stop completely. Give it some time. Heating it up to 60 degr.C is recommended.
Also less NOX fumes to bother with when you add small amounts.
If you keep a cover on the beaker (I use an erlenmeyer flask), you can check by lifting the lid, letting fresh air in. This will create brown fumes if there is still enough free nitric in solution.

You made enough AR to dissolve almost a troy ounce of gold. So expect to dissole some grams of copper while cementing. A good thing is copper takes about four times as much nitric to dissolve as gold.
Let us know how much gold was in there when you're done. With a button picture please :G .

Martijn.

 

[butcher]

Martijn,

A small correction to the statement above.
Copper and silver will dissolve in nitric.

Gold will not dissolve in nitric, when nitric is used it is only an oxidizer to get things started (the nitric is only oxidizing the gold temporarily in order to temporarily bump loose the free electron from the gold atom so then the three or four (chlorines being reduced to) chlorides can take over to share the golds electron forming auric chloride salts, copper will dissolve in nitric forming a nitrate salt, gold will not, gold is not forming a nitrate salt in the reaction with aqua regia.

silver will form a nitrate as will copper, and it is silver not gold, that takes less nitric to dissolve than copper.

You have confused gold with silver in your statement above.

 

[Martijn]

Butcher, thank you for that correction.
Regarding the gold dissolving, I meant gold will re-dissolve to some extent when cementing in pregnant AR and excess nitric is still present. Even when SBM is applied. As I have to admit having witnessed this a few times.

The comparison I made was to say that cementing with copper (in AR) will consume more nitric compared to dissolution of gold in AR.
Really with absolutely no advantage whatsoever ... I realize now (double facepalm smiley here) You can't cement on gold on gold, and comparing a dissolution reaction with a displacement reaction...oh well. sorry.

I thought it takes about 1 ml of Nitric in a HCL environment to dissolve (I mean oxidize and thus get liberated to bond with the clorides) one gram of gold. Is this wrong?

Please confirm if so.

My understanding was: 100ml of AR 3:1 contains +\-25ml of nitric >> would 'dissolve' approx. 25 grams of gold?? (@ 60 degr. C, Capped off erlenmeyer, Slow addittions HNO3, gold foils)
The nitrix acid is not part of the new desired compound, but consumed by the reaction and converted to NO / NO2 during the reactions.

Martijn.

 

[butcher]

With aqua regia where the copper is displacing gold from a chloride solution not figuring usage of free nitric acid in solution it takes around 3 moles of copper to displace about 2 moles of gold from aqua regia, with any excess or free nitric in the chloride based solution you will dissolve more copper before the gold will begin to cement from the chloride solution, at a rate of somewhere around 3moles of copper for every 8moles of free nitric left in solution.
2AuCl3 + 3Cu--> 3CuCl2 + 2Au
3Cu + 8HNO3 --> 3Cu(NO3)2 + 2NO + 4H2O

It takes about one mole of copper to displace 2 moles of silver from a silver nitrate solution.
2AgNO3 + Cu --> Cu(NO3)2

Again with any excess or free nitric in the nitrate based solution you will dissolve more copper before the silver will begin to cement from the nitrate solution, at a rate of somewhere around 3moles of copper for every 8moles of free nitric left in solution.

3Cu + 8HNO3 --> 3Cu(NO3)2 + 2NO + 4H2O

You are correct it takes about 3.8 ml of HCl and about 0.95 ml HNO3 to dissolve a gram of gold.
About 118.29 ml of 32% HCl acid and about 29.5ml of HNO3 acid to dissolve a troy ounce of gold.
Or about four fluid ounces of HCl and about one fluid ounce of HNO3 to dissolve an ounce of gold.

 

[1mysurveymail]

Martijn, Thanks for all your help l will make stannous and cemment then write the result.

I use a few inches of lead-free solder in 100ml of HCl

To denoxx your AR you can usee "sulfamic acid crystals." commonly sold in the USA in the tile flooring department as "grout cleaner." A little teaspoon is generally all you may need.

Best of luck.

 

[ekrem duran]

Martijn ve Butcher thank youso much for helping and explaining .

l make my own stannous solution and test my green aqua Regia colors change light brown. I think its because l must have boild too much. Anyway at this time i used hydrazine hydrate as precipitator .Something settled a little to the bottom of the solution, but its color was close to black not brown is it normal?

I'm collecting my gold powder for now, I'll melt it in the future and send you pictures

I did one more action later, this time I took note of some things, I thought that if there is a transaction I did wrong or missing, it would be easier for you to correct me.

78 gr gold fingers boadrs etc.
100 ml hot water
100 ml nitric acid
boild half an hour and filterd
making aqua Regia 20 ml nitric 60 ml hcl
dissolwed all gold foil.
for adjust ph add some urea but ph not changed
and add some sodium hydroxyl half tea spoon
and measure ph as 13
anyway add hyrazine hyrdat
this time it collapsed into a few chunks
the result seemed low to my eyes but this time I made .
photos are in below

 

[ekrem duran]

Martijn ve Butcher thank youso much for helping and explaining .

l make my own stannous solution and test my green aqua Regia colors change light brown. I think its because l must have boild too much. Anyway at this time i used hydrazine hydrate as precipitator .Something settled a little to the bottom of the solution, but its color was close to black not brown is it normal?

I'm collecting my gold powder for now, I'll melt it in the future and send you pictures

I did one more action later, this time I took note of some things, I thought that if there is a transaction I did wrong or missing, it would be easier for you to correct me.

78 gr gold fingers boadrs etc.



100 ml hot water
100 ml nitric acid
boild half an hour and filterd






making aqua Regia 20 ml nitric 60 ml hcl
dissolwed all gold foil.
for adjust ph add some urea but ph not changed
and add some sodium hydroxyl half tea spoon
and measure ph as 13
anyway add hyrazine hyrdat
this time it collapsed into a few chunks




the result seemed low to my eyes but this time I think I made .

Can you please tell me, is there a place I do wrong?
What are the tricks I should do to smash gold more efficiently?


yesterday l made an operation goldfinger board part with
pins ( the pins weren't all covered). This time not boild 1 hour steam
bath.

When I filtered with a sieve, a lot of gray residue accumulated with gold foils .
when When I filter with filter paper, a substance like white mud with gold dust
what is this gray sediment and what is this white mud how can i get rid of it
Could it contain silver?

shod l test it whit stannous?

 

[Martijn]

If this science was easy, and there was a lot of profit to be made in processing E-waste: every idiot would be doing it (in the kitchen while making dinner) and having success and staying safe and healthy while doing it...
((This was sarcasm and not good advise.. btw... for those with gold fever and pink sunglasses!!))

First: Those nice clean gold foils in the filter your'e HANDLING WITHOUT GLOVES!!!!??? might even be as much as 0.1 gram of gold.> 5 euro's worth there... max, if your'e lucky..

I said the first time you made enough AR to dissolve an Ounce of gold. Now you have done the same..

And you've created tin paste with that nitric leach. > study to learn how to avoid and how to solve it.

Forget Urea!!!!! Why? > study!!
Forget You Tube... the amount of ads are an indication for the true reason the video is made in the first place. Lots of oohhs and aaahs, shiny stuff and likes and shares... ooooh i'm soooo popular omg! and one disclaimer in the beginning to keep the lawyers out.

If you don't start reading and asking before you attempt anything as a very inexperienced member, you will hit a brickwall here on GRF with this experimenting while we just said not to do it.

Set your toxic chemicals and metals in solution aside in a safe place from kids and animals along with your GOLDFEVER and read, study, ask if assumptions are correct, set up a plan for your material, share your plan with us and be prepared for comments of both helpfull and sarcastic nature.

A post I made yesterday:
( don't feel like repeating myself again..)

Safety first: Work in a fumehood or outside upwind. Or better yet, scrub the fumes. Use gloves.

Put the foils in a beaker, barely cover them with HCL. 30% strong is fine. Put on low heat in a dry sand bath. 60 C. Measure with a laser thermometer.
Add some drops of nitric. Cover with a watch glass.
Watch and wait until no more tiny bubbles come from the foils. This can take a couple of minutes to half an hour.
Then add some more drops if there is still visible gold.

Overshooting nitric is a problem we deal with a lot here on the forum. And then explaining why NOT to use urea to try and solve a problem easily avoided.

In time you will learn how much it takes to dissolve your foils and guesstimate a safe amount to start with.

But as jimdoc said:
Study safety and dealing with waste to handle and dispose of the toxins you create.

For your health's sake and the environment.

Some links to get you started:
Welcome to all newbies
https://goldrefiningforum.com/phpBB3/viewtopic.php?f=33&t=796
And:
Help where do i start learning these skills
https://goldrefiningforum.com/phpBB3/viewtopic.php?f=49&t=28521

Make sure you know how to get back to earth before you jump onboard the spaceship..

hydrazine hydrate you say, never used it, can't give any advice on it, but from the MSDS: (took me 5 seconds to find this info)

"Potential Health Effects
Eye: May cause irreversible eye injury. Exposure to the vapors or liquid may cause temporary blindness. Causes severe eye irritation and burns.
Skin: May be fatal if absorbed through the skin. Prolonged and/or repeated contact may cause irritation and/or dermatitis. May cause skin sensitization, an allergic reaction, which becomes evident upon re-exposure to this material. Contact with liquid is corrosive and causes severe burns and ulceration. Contact with the skin may dissolve hair.
Ingestion: Harmful if swallowed. Causes gastrointestinal irritation with nausea, vomiting and diarrhea. May cause liver and kidney damage. Causes digestive tract burns with immediate pain, swelling of the throat, convulsions, and possible coma. Exposure may cause anemia and other blood abnormalities.
Inhalation: Harmful if inhaled. Irritation may lead to chemical pneumonitis and pulmonary edema. May cause liver and kidney damage. Causes severe irritation of upper respiratory tract with coughing, burns, breathing difficulty, and possible coma. Vapors may cause dizziness, nausea, itching, burning, and swelling of the eyes.
Chronic: Repeated inhalation may cause chronic bronchitis. May cause cancer according to animal studies. Repeated exposure may cause sensitization dermatitis. May cause reproductive and fetal effects."

Have fun!....


BE SAFE!!


Martijn.