Beginners GuideGold Recovery Secrets

Aqua Regia Process


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


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  1. 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

    1. 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.

  2. 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!

      1. 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…….

  3. 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 🙂

  4. Assalam Mr omar pls explain me the way
    When we crash the rock we put the dust in nitric acid first or what pls send me a video to my WhatsApp (00212661177261).thks br

  5. salaam alaikum Umar.
    please i need info on why the dust i get is always dark and its very smooth and light. and my gold solution always turn black or brown, but then the dust under it looks dark and very light, when i filter it. it always goes with the solution water it doesnt stay under

  6. 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.

  7. 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.

  8. after i dissolved golden pins .. i got the yellow gold water … then i add urea to neutralize nitric acid .. i dont know if i add much urea or not ..i kept adding urea seem i added excess .. but when i add sodium meta bisulfite i got much fizzy .. brown fumes .. so suffocation odor .. i thought the reaction is ok .. so i added much sodium meta bisulfite .. .. gold powder not precipitated .. and the solution become pale yellow green color …. i wish u advise me to solve this problem

  9. Hello sir
    I have problem
    I can not retrieve gold from aqua Regia
    sometimes after adding urea white sludge creats to bottom of beaker and sometimes not
    When adding SMB, brown powder does not form and sometimes its pink
    I do not know where the problem is
    please guide me

  10. Sir I add sodium metabisulfite in aqua regia without neutralizing it. No ppt are formed. Now tell me what I do about that. Black color solution is formed.

  11. I done a same thing, but my aqua regia solution becomes light green color! will u please explain me why?

  12. thank you for your helpful information
    I have a mistake in this process, i desolve electronic circutes gold layers in acqua regia, and achieve green solution, after that add some urea to that but nothing happend then add smd to that until melting stoped and the color of solution changed to dark brown and the smd setlled down, i think i add more of that, melting had been continuing for 4 hours and the smd was in bottom of glass so I added some acqua regia step by step to that to solve smd on it when i added that started melting rapidly with yellow and black foam after 3 haur melting stoped and i add some smd again and nothing happend i just have thick black brown solution with something white, black and yellow thing in bottom of glass, i dont know what i do after that processes!

  13. hi thanks alot beacause of your excellent informations.please please help me imediately. i add amd cpus to the conteiner after that i add aqua regia to the container and leave it for 3 haurs. after melting was dont i filter them, the solution color was dark green with some yellow color in that. i add extra hcl and water in that and increase the volume quadruple. after filter it I had clear green yellow color, I add urea with water until bubbling is finished, and add smb to some water ( I had 20 grams gold in water and added 24grams smb) next day filter the solution (the solution has very clean and green color) and I burn filter with botox but unfortunately after melting I had just 2 grams gold. what is wrong? please help me

  14. salaam alaikum
    what is the required amount of SMB to precipitate one gram of gold?
    thank you in advance.

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