colloidal gold

[arthur kierski]

i need help in finding a way to detect suspected coloidal gold in a solution-----especially in a ssn solution

thanks all,
Arthur

 

[Geo]

usually, color is a good indicator. Dr. Poe made a post showing the different colors of colloidal gold and other metals. i would think red hues would be more suspect purple through red. anything blue i would suspect something else.

 

[glondor]

Hi Arthur. I drew a blank on ssn solution as I just woke up. (I hate acronyms.)

Could you do this? Take a 50 ml dip sample of your solution. (((You would have to decide if stirring would help or hinder your goal here. I think I would dip from a well settled solution as it is gold in suspension you are looking for and stirring will incorporate any settled material in your test.)))

Evaporate the sample to a dry state, dissolve any residue in your test beaker in a drop of A/R. Denox with a prill or 2 of urea and test A/R drop with Stannous. Any reason why this should not work?

According to Dr Poe, Colloidal solutions can hold a tremendous amount of gold. I would have to look it up but I think it was something like 30 % by weight per gallon. A tremendous amount indeed.

Evaporating to 1/3 should make it all settle out. There is also Floculation agents that are purported to work.

 

[Geo]

ssn is saturated sodium nitrate solution.

 

[glondor]

Thanks Geo. Is there any reason the test I suggested would not work?

 

[Geo]

it should work, personally, i would use the hcl/Cl and test right away. theres no need to dry the sample. put a small sample in a test tube and add a few drops of hcl and then add a drop of bleach. if its gold or even silver, there should be a reaction. then test with stannous.

 

[samuel-a]

ssn is saturated sodium nitrate solution.

Hi Geo

Just for the record, SSN leach stands for Saturated Saline + Nitric acid.

 

[Geo]

saline - sodium, tomato - tomato. :lol: i dont know how to type the accent.

 

[samuel-a]

Saline, should be pronounced as such - NaCl. :mrgreen:

 

[butcher]

SSN leach (saturated salt and nitric acid) is basically a form of aqua regia (poor mans), the salt NaCl and hydrogen from the acid makes HCl in solution, this and the free nitric in solution makes aqua regia.

 

[arthur kierski]

i will go after glondor test ,using afterwards hcl-cl(geos idea)-----
thanks for the moment,
Arthur

the results i will pass to members
Arthur

 

[g_axelsson]

I can't see how colloidal gold could ever exist in any sort of AR, even if it's poor mans AR or SSN. The only way it could exist is if the nitric is gone.
Take some solution away from the solids, add a drop of nitric acid (or nitrate + HCl in the case of poor mans). If the color stays it shouldn't be because of colloidal gold. If it disappear test with stannous as usual.

Also test the original solution and compare it to the result from above. If the untreated liquid contains gold it is hard to say something about colloidal gold unless the reaction is a lot stronger from the treated sample.

/Göran

 

[Geo]

Goran, thats one of the reasons removing tin from your scrap is so important. tin will follow gold through the entire process. as the nitric is consumed to the point it will no longer dissolve the colloid, any tin remaining (a very minute amount of tin will precipitate an alarming amount of gold) will do the same thing in your solution as it does in a stannous chloride test. depending on concentration of gold and/or tin and a couple of other factors (like other metal content and even temperature) determines the color of the colloid produced.