deep(strong) purple solution

[arthur kierski]

how can one recover the gold (coloidal) from such a solution?thanks for replies

 

[4metals]

I don't know of a quick fix for this one, other than boil the solution down to a crust and roast it to decompose the oxides. Then you can remove the tin first via acid treatment rinse the remaining solids and refine them in Aqua Regia as normal gold containing solids.

Once the gold gets hung up with the tin it is a nightmare.

Good luck, please post your results.

 

[arthur kierski]

i will do exactly what what you sugested and then send the results
thanks 4metals-----

 

[arthur kierski]

4metals,after trying many ways,i came with a simple solution that gave splendid results-------------------------------
i added to the solution hydrazine and boiled ,gave a 5minutes rest (to cool it) and the gold powder dropped -----the solution became green colour with no gold(stanous chloride test)----any questions will be pleasurable answered------Arthur

 

[Platdigger]

Arthur, are you sure the hydrazine did not also reduce the tin?

 

[arthur kierski]

platdigger--i am not sure if the tin was reduced----but i learned that hidrazine in a chloride solution will leave base metals in the solution-----with formic acid i am sure that base metals stays in the solution------
the hidrazine formed a very very fine powder which i had to filtrate twice with special filter paper---the liquid left was green(light green)---i will now dissolve this fine powder in ar or hcl-cl to recover the gold----
ps : i measure rh by using hidrazine in a rh sulfate or chloride solution and base metals stays in the solution
thanks
arthur

 

[Oz]

Arthur,

I would suggest a wash in HCl before proceeding. You do not want to end up back were you were.

 

[arthur kierski]

oz,you mean an hcl wash prior to hcl-cl or ar?wash the fine powder?
thanks
arthur

 

[Barren Realms 007]

I think OZ suggested that because of the statement about the tin in the mix.

 

[Oz]

Yes, before taking the gold into solution.

Your hydrazine should have reduced most elements and washing out base metals is always good procedure. In this case with tin most likely reduced as well you could find yourself with colloidal gold all over again if you do not remove it. I am sure at some point and time you have used AR on crushed electronic scrap, I'll bet you had a lot of purple.