Introduction:
Aqua regia is a Latin word which means royal or kings water. so named by alchemist because it can dissolve noble metals like gold and platinum. This article is about aqua regia process for gold dissolving and extracting. Aqua regia is a combination of HCL and HNO3. 3 parts of HCL and 1 part of HNO3 make aqua regia for gold dissolving. Let’s know about gold extraction from aqua regia.
There are many procedures for gold precipitation from aqua regia. For example, we can use Sodium metabisulfite, oxalic acid, iron and some others. But I like SMB (sodium metabisulfite) and we shall learn about this in this article. Friends, If you are new in gold recovery then you should about aqua regia status. Is aqua regia pregnant with gold or not.
Gold Testing:
Gold testing is the main part of aqua regia process. Now, the question is this, How to check gold in solution. You can use stannous chloride for the gold test. Simply take a pinch of stannous chloride and dissolve in water. Take a drop of gold solution on filter paper piece and use stannous chloride solution on it. If the color drop becomes black or dark brown then it means gold is in solution. If nothing happens then no gold in solution. Many people use a cotton bud for this test but I don’t like this. Because, why we waste a lot of gold in this.If you want to learn about Stannous Chloride then please read Gold Recovery Chemicals article. Click Next Page Button…Continue
a.o.a uma bhai. again a very informative post. now i have a question, i burn some mobiles and recover gold. next time i try but i got a blackish brown an some green color solition. it not neautrelise nitric acid. what to do please help me
Test solution for gold with stannous chloride.
The green color shows that some copper is in solution.
Filter black-brown powder and melt it.
can use this method for run of mine (Primary gold) ?
and what type of Urea and Sodium setabisulfite ?
Because I can not precipitate the gold from solution using Urea and Sodium setabisulfite.
thanks for reply. the solution color was green and black and some yellow colored. i filter buy i got nothing. i use sufuric acid and i got a white crystals. and they again solved inside solution untill i filter!
dear umer how can remove lead and aluminium in A-R Solution .already i used h2so4 but SMB not working gold dust not sat ell down. kindly help me…….
Add extra water. Your problem will resolve.
Dear umar i try this add more SMB and more water but no result solution gone light blue color .before its light green.. but no gold dust please give advise how can i do…….
please answer me ..
do you neutralise the nitric acid before adding smb?
Salam kenal 🙂
Saya olah cellphone, pertama saya bakar sesuai dengan petunjuk anda di youtube.
Akan tetapi sesudah di Aqua regia saya endapkan dengan SMB, hasilnya bagus dalam jumlah 2kg cellphone.Saya olah ulang dengan sistem yang sama dengan jumlah cellphone 10kg tidak jadi.cuman endapan seperti lendir putih.mohon solusinya Master 🙂
Thanks for your valuable information my friend.
You are welcome.
I have a problem and I was wondering if i can get some help, (First time)
I had made up 2 solutions of HCL to dissolve the base metals on some PCB’s and old pins that i had collected, the other to was the Gold plated CPU’s (lucky enough had been given 10 Intel Pentium Pro old ones!).
After washing the CPU’s and purifying them of base metals, I decanted the fluid and proceeded to make a A/R solution to which i added my CPU’s (fine i believe).
Heres the problem I added the PCB and the gold pins directly into the A/R and completely forgot the wash and left overnight (what a plonker).
Woke up this morning with a Dark green cloudy liquid, to which I was mortified as it was not as i expected, I filtered immediately and witnessed the gold had been removed from the CPU’s and hopefully dissolved into the A/R
I believe Base metals have been dissolved into the solution (i.e copper,lead and alu) as it is DARK GREEN not a beautiful Yellow/Gold liquid.
Alas my query from here how do I proceed, I have been scouring this forum for the last day and have read parts of HOKE and cannot find a solution to my problem.
You are using the extra amount of SMB.
Dear Sir Asslamulaikum, i m Mohammad mahamudul hasan .I m from Bangladesh..i want to know about SBM powder..please tell me details of SBM powder ..what is this . what kind of this powder.
Wa Alaikum Salaam.
Read Gold recovery chemicals.
Read gold recovery chemicals article.
thanks good
you are welcome.
Hcl available nahi he bhopal me kya karu sir bataye
namak ka tezaab keh kar mango
I done a same thing, but my aqua regia solution becomes light green color! will u please explain me why?
Salam Professor
How to remove annoying metals from gold resulting from metabisulfite deposits?
Thank you 🙏
Salam Professor
How to remove annoying metals from gold resulting from metabisulfite deposits?
Thank you