aqua regia neutralized with baking soda

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davidrey

New member
Joined
Jun 29, 2014
Messages
4
Hi, my name is David Rey and im new in refining gold and in this forum.

Let me tell you a little about my self, im a computer tech and i work with a lot of electronics, i use to invest my money buying gold from APMEX, I like to buy gold because it is an long term investment and i have been done reading and research about buying and selling but i like more to buy gold and silver.

one of my coworkers was studying how to refine gold, but he only looked at youtube videos, i told him gold refining was a process and have to be careful about what he was doing in terms of safety and what steps to follow and after a while he could not get a single gram of solid gold from cell phone pins, boards and IC chips. I know he made the mistake of putting the whole board in nitric acid without cleaning the board and taking off other components like surface mount resistors and little pieces of steel, iron and speaker magnets. finally he gave up and he was about put in the trash can some plastic bottles filled with what i know is nitric acid and aqua regia, some of the bottles have a orange red mud, others have red wine color mud, i asked him to write everything he did before he handled all the acid containers and mud containers for proper neutralization and disposal.

In a nitric acid container he put the whole boards without taking off small electronic components, after the nitric acid did its work, he filtered the remaining metals together with the gold flakes and put it in a glass container filled with nitric acid 42 Be 68%, hydrochloric acid 20 Be 32%, one part nitric acid three parts hydrochloric acid and the next day he added sulfuric acid to drop inpurities, he filtered again and when using sodium sulfite the gold will not drop, only awhite foam will show and then it will disappear every time he puts sodium sulfite in the aqua regia and nothing will drop.

In separate container the tried to cement the gold putting a lot of copper, until now, every piece of copper he put in the aqua regia it will desappear and the gold will not cement, another thing he did is to add baking soda while the aqua regia was boiling and he ended up with a black crust in the reaction flask and lasting he did is to add baking soda to the aqua regia in three 24oz plastic containers and the result was a red and orange mud in the solution and that what he have done until he gave up and just give me all the chemicals and lab glass, for the reaction flask with the black crust i used clean aqua regia to clean it and save the acid because it turn clear yellow again after it dissolve the black crust, the reaction flask looks expensive because it has good known brand stamp and the rest of glassware ass well, he gave me all the glass ware as well i think he got frustrated, i asked him to do a research and read before doing something but he didnt and just did what he saw on youtube.

I downloaded a copy of hokes book from another location and i have being reading, i got most of the chemicas needed to do the process, I really like to read but i cant find a section that describes dropping gold with baking soda instead of copperas, or boiling the aqua regia to get rid of nitric acid.

for the used nitric acid container i did a little experiment and i ad hydrocloric acid to a small beaker and i got clear cristals from the solution wich i think are siver salt or silver nitrate, the silver crystals are mixed with green crystals and some have a combination of both colors, some of them are flat and long like triangles.

to get familiar with the process i downloaded hokes book and follow the direction described in the refining precious metals and commonest case section but i cant find anything that describes dropping gold with baking soda, only for accidental contact with skin and how to neutralize it, ia have been looking on the forum as well without luck.

This is what i know to this point, any help will be greatly appreciated concerning the orange mug of baking soda in the aqua regia containers, i have never done gold refining and i think it is a science and now since my friend gave me the lab glassware, chemicals and some tools i want to learn and read everything i need to get familiar with process before attempting to drop the gold from the baking soda mud in the aqua regia containers

thanks for taking the time to read, please any reply will be greatly appreciated
 
Honestly, you may be chasing after nothing. Did your friend tell you how much material
or what kinds of materials that he "processed"? In small quantities of low value scrap, you
may be the proud owner of more hazardous waste than you do precious metals in sludge form.

See if you can determine what the source material was and perhaps someone here can help
you see if anything can be done with this mess. If there is no more than possibly a gram or
two of gold, will it be worth it to try and fix someone else's problem over $85 worth of gold
in two grams that may be hidden in what you were given?

Just trying to be helpful. It is a fun hobby but it may not be best for you to start like this
in this pursuit. Just saying. 8)
 
davidrey said:
i cant find a section that describes dropping gold with baking soda

and you will not find it because it can not be done. baking soda will neutralize the acids.

what i think you should do from here is:

make sure your copy of Hoke has all the pages. if not a copy may be found here on the forum

stop recovering for now & learn a little more

evaporate down to a syrup and start again. (search Hoke's for "syrup")

important things to read are:
the safety section
http://goldrefiningforum.com/phpBB3/viewforum.php?f=47

legal things
http://goldrefiningforum.com/phpBB3/viewforum.php?f=36 (acid in the trash is not good)

and the attached file
 

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Thanks a lot for your reply, im familar with waste management and how to neutralize some acids, we use chemicals to make costume electronic boards and before doing anything to a acid container i neutralize it with baking soda and add tab water and handle it to a chemical waste management guy that comes to the shop every tow weeks to pick it up.

Its been almost a month reading hokes book in my free time and came to the conclusion that i need to filter the mud and since the acids have been neutralized i have to prepare copperas in hot water and add hydrochloric acid just to make the copperas e grean solution but still i have some doubts about the orange mud, it may contain gold or silver, base on what i have been reading baking soda just neutralize acids and as you said it wont drop gold.

I think it worth going through this because im learning and i like gold, its been a year since i started building my portfolio i gained some experience on buying and testing PMs but not how to refine it. When i went to his home to clean and pick the tools and glassware i noticed a big box full of cell phones and computer memories and he just gave me the box, in another plastic box there were maybe two hundred PCB boards from cell phones and computers, in a plastic container together with the orange mud i notice really small pieces of gold and it is more noticeable with a flash light, i think he just gave up when he was about to get it right.

This is what i have until this moment, ill keep posting for any thing i will be doing, I have a copy of hokes book from this site now and it looks de same that i have, thank you for taking the time to reply, you are very cool guys, i have been asking some refiners about this problem but they wont tell me anything helpful.
 
i think page 62 or 63 is missing from random internet copies of Hoke

since you are set on cleaning up the mess, try (SMB) Sodium metabisulfite it's the same as copperas & easier to find. 1 gram of smb will drop 1 gram of gold

filter the extra solution leaving the "mud"
test the extra solution with (SnCl2) stannous chloride for any values

dry the mud

incinerate the mud to red hot without melting

from here "personally, i would" ad HCL or Muriatic Acid & heat to rid your powdered mud of base metals, you may need a little extra hcl & more then one digestion to remove the base metals. you will see discoloured solution if hcl is working, decant & start again till no colour change.

you can do the same with Nitric Acid but you may run into a metastannic acid problem (tin powder) go with the hcl for now

when hcl digestion is complete, dry the "cleaner" mud, incinerate the "cleaner" mud to red hot without melting

ad "cleaner" mud to a mixture of 50% distilled water & 50% of 70% Nitric Acid (or close %) just enough to cover the cleaner mud

ad heat, you will see the nitric eating any of the leftovers away, if there is any

you should be left with gold foils only, unless there was any PGM in the original scrap

weigh dried foils or powder

now you can wash the foils & ad to AR or acid/bleach to put gold into solution (AuCl) making sure not to use too much AR
you can try Sulfamic Acid to neutralize any extra nitric acid

ad just a touch more SMB then gold calculated in weight (1 gram gold ? mix in 1.5 grams SMB)

let settle, decant & use Harold_V washing method


you will find that many of us will have a different method depending on our experience levels

i am sure someone will add there 2 cents, its always a good thing

remember to test your solutions with SMB to make sure there is no values left in old solutions
 
Thanks for your reply necromancer i really appreciate it, these are some pictures that i took before starting cleaning and checking what can be saved, and you might have a better idea of what i have in my hands, thanks a lot.
 

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Miscellaneous precipitated hydroxides, the color might be caused by iron hydroxides. If so, there is no gold in solution (test by SnCl2!).
 
i cant tell by the photos,

there may be 500 or more grams of baking soda in there. colour leads me to think its rust (iron)
 
necromancer said:
since you are set on cleaning up the mess, try (SMB) Sodium metabisulfite it's the same as copperas & easier to find. 1 gram of smb will drop 1 gram of gold
SMB is not the same thing as copperas but both chemicals can be used to drop gold from solution.

David, learn to test for gold in solution (stannous chloride) and then test your liquids. If there is no gold in solution then it probably is with the solids.

I didn't see any leftover circuit boards or residues from components in your pictures. If there was any metal left in the mix, for example hidden tracks inside a circuit board, then the little gold there were could have cemented out on the metal and been thrown away with the trash.

Test your mud, your liquids and any solids left until you find the gold. If there isn't any gold left no matter what you try you won't get any gold in the end.

Göran
 
g_axelsson said:
necromancer said:
since you are set on cleaning up the mess, try (SMB) Sodium metabisulfite it's the same as copperas & easier to find. 1 gram of smb will drop 1 gram of gold
SMB is not the same thing as copperas but both chemicals can be used to drop gold from solution.

David, learn to test for gold in solution (stannous chloride) and then test your liquids. If there is no gold in solution then it probably is with the solids.

I didn't see any leftover circuit boards or residues from components in your pictures. If there was any metal left in the mix, for example hidden tracks inside a circuit board, then the little gold there were could have cemented out on the metal and been thrown away with the trash.

Test your mud, your liquids and any solids left until you find the gold. If there isn't any gold left no matter what you try you won't get any gold in the end.

Göran

to be more clear

smb & copperas will drop gold out of solution
smb can be found at most wine & beer making houses, i get 1kg for 15 dollars
i have to order copperas off the internet
 
David,

My suggestion to this problem:
Test the liquid (it is doubtful to hold any value), and treat it properly for waste disposal.

Study proper waste disposal, when you have a company that will take your toxic waste what your doing may work if they will take it that way, but it is not the proper way to treat your waste for disposal.

Dry the powders (which may or may not contain value), label them as to what they contain, and where they are from, store them in a safe place.

Then get out Hokes book again, and study it, and the forum, take those baby steps needed to learn, when you learn to walk then you may want to tackle this mess of powders.

You have a lot of learning to do before you are ready to tackle a mess like this.
If you study and learn how to process properly, and understand the principles involved in recovery and refining then you can tackle most materials or most any mess.

But beginning to try and learn with a mess on your hands, I do not think will help you much at this point.

Read Hoke's book until you understand what she is doing, and teaching, not just in one step of a process, but the overall picture as well, to get an understanding of the basic fundamentals of recovery and refining. Use Hokes book doing the small experiments suggested in the book, study it, and the forum, the safety section and dealing with waste in that section, The guide to the forum in the general reaction list can be a good starting place, begin learning on simple procedures and a simple material like memory fingers, and work your way up to harder materials and processes, in doing this you will generate some small messes to deal with, that will help prepare you for dealing with a big mess like you have now.
 
Hi, my name is David Rey and im new in refining gold and in this forum.

Let me tell you a little about my self, im a computer tech and i work with a lot of electronics, i use to invest my money buying gold from APMEX, I like to buy gold because it is an long term investment and i have been done reading and research about buying and selling but i like more to buy gold and silver.

one of my coworkers was studying how to refine gold, but he only looked at youtube videos, i told him gold refining was a process and have to be careful about what he was doing in terms of safety and what steps to follow and after a while he could not get a single gram of solid gold from cell phone pins, boards and IC chips. I know he made the mistake of putting the whole board in nitric acid without cleaning the board and taking off other components like surface mount resistors and little pieces of steel, iron and speaker magnets. finally he gave up and he was about put in the trash can some plastic bottles filled with what i know is nitric acid and aqua regia, some of the bottles have a orange red mud, others have red wine color mud, i asked him to write everything he did before he handled all the acid containers and mud containers for proper neutralization and disposal.

In a nitric acid container he put the whole boards without taking off small electronic components, after the nitric acid did its work, he filtered the remaining metals together with the gold flakes and put it in a glass container filled with nitric acid 42 Be 68%, hydrochloric acid 20 Be 32%, one part nitric acid three parts hydrochloric acid and the next day he added sulfuric acid to drop inpurities, he filtered again and when using sodium sulfite the gold will not drop, only awhite foam will show and then it will disappear every time he puts sodium sulfite in the aqua regia and nothing will drop.

In separate container the tried to cement the gold putting a lot of copper, until now, every piece of copper he put in the aqua regia it will desappear and the gold will not cement, another thing he did is to add baking soda while the aqua regia was boiling and he ended up with a black crust in the reaction flask and lasting he did is to add baking soda to the aqua regia in three 24oz plastic containers and the result was a red and orange mud in the solution and that what he have done until he gave up and just give me all the chemicals and lab glass, for the reaction flask with the black crust i used clean aqua regia to clean it and save the acid because it turn clear yellow again after it dissolve the black crust, the reaction flask looks expensive because it has good known brand stamp and the rest of glassware ass well, he gave me all the glass ware as well i think he got frustrated, i asked him to do a research and read before doing something but he didnt and just did what he saw on youtube.

I downloaded a copy of hokes book from another location and i have being reading, i got most of the chemicas needed to do the process, I really like to read but i cant find a section that describes dropping gold with baking soda instead of copperas, or boiling the aqua regia to get rid of nitric acid.

for the used nitric acid container i did a little experiment and i ad hydrocloric acid to a small beaker and i got clear cristals from the solution wich i think are siver salt or silver nitrate, the silver crystals are mixed with green crystals and some have a combination of both colors, some of them are flat and long like triangles.

to get familiar with the process i downloaded hokes book and follow the direction described in the refining precious metals and commonest case section but i cant find anything that describes dropping gold with baking soda, only for accidental contact with skin and how to neutralize it, ia have been looking on the forum as well without luck.

This is what i know to this point, any help will be greatly appreciated concerning the orange mug of baking soda in the aqua regia containers, i have never done gold refining and i think it is a science and now since my friend gave me the lab glassware, chemicals and some tools i want to learn and read everything i need to get familiar with process before attempting to drop the gold from the baking soda mud in the aqua regia containers

thanks for taking the time to read, please any reply will be greatly appreciated
Hi David Ray,

I am new to this website as well. Also, when I first started out, I did experience some of the same problems and was under some of the same misconceptions. I will add Photos to show what I experienced after I explain a few things. First, yes baking soda will drop gold. At the same time, it will drop everything else as well. Baking soda will neutralize your acid causing all impurities to drop from solution, especially after you let it settle completely. I the first thing that I think you need to look at is the “reactivity series of metals chart.” That will give you a better understanding of how these different metals react in different solutions and build a game plan, for how to tackle your situation. Also, different metals will come out as different colors, when it drops from solution, depending on what type of method you use. For example, silver will have a Tiffany blue color that’s the reason for the jewelry store to have the color as apart of there theme and logo. Gold, can be a purple color especially when there are small or trace amounts of it and etc.… what I would do if I was you is

First, get a copy of the reactivity series of metal chart. You can type that into the search engine go to images and print one out.

Second, look at Hope’s book like others have suggested on the forum.

Third, get some simple PH strips. Find out what the pH of your drinking water is, find out what your pH of coffee is, find out what the pH of soda (soda pop) is. (your acid solution should be the same pH as your drinking water when neutralized (ph 7)). After adding baking soda.

Fourth, get you some precious metals testing solution that you can add to the solution it will help you so that you’re not chasing after something that may not be there. (Don’t add it to the entire amount that you’re processing make sure you add it to a sample amount.)

Also, make sure before you attempt to drop gold you neutralize the acid. I recommend, SULFAMIC Acid. make sure your solution still has a little heat to it and add slowly. Omegageek64 has a video on it on YouTube. I hope all of this helps and good luck on your journey!
 

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The first picture is me separating the Tiffany blue from the other metals.

The second picture is an example of a precious metal testing solution.

The third picture, is when I made the same mistake a while ago and the end result of it (adding baking soda to solution and let it settle that your coworker did.)
 
The first picture is me separating the Tiffany blue from the other metals.

The second picture is an example of a precious metal testing solution.

The third picture, is when I made the same mistake a while ago and the end result of it (adding baking soda to solution and let it settle that your coworker did.)
Why are you replying to a post that was posted in 2014??

And much of your advice are not sound but quite meaningless.
Baking soda rises the pH and at certain levels of pH the hydroxides of different metals will loose solubility and drop out.
This is not something we normally want. Many hydroxides are a pain in the A** to handle and filter.
Depending on how yo dissolve the Gold you may or may not need to destroy the Nitric with Sulfamic acid, not neutralize (which mean pH 7).
We want it to be around 2 ish, I personally have never adjusted pH before dropping the Gold.
I use SodiumMetaBisulfate for that.
One can if the solution is very dirty cement it out on Copper per the Reactivity chart you mentioned.

Have to run.

Basically check which posts you reply to and make sure your advice is sound.

Welcome in by the way😀
 
Why are you replying to a post that was posted in 2014??

And much of your advice are not sound but quite meaningless.
Baking soda rises the pH and at certain levels of pH the hydroxides of different metals will loose solubility and drop out.
This is not something we normally want. Many hydroxides are a pain in the A** to handle and filter.
Depending on how yo dissolve the Gold you may or may not need to destroy the Nitric with Sulfamic acid, not neutralize (which mean pH 7).
We want it to be around 2 ish, I personally have never adjusted pH before dropping the Gold.
I use SodiumMetaBisulfate for that.
One can if the solution is very dirty cement it out on Copper per the Reactivity chart you mentioned.

Have to run.

Basically check which posts you reply to and make sure your advice is sound.

Welcome in by the way😀
Hi, I did not realize that I responded to a post from 2014. Thank you for letting me know that. Also, I was not telling the person to destroy the nitric acid I was just stating what happens when you add baking soda to it. Also, when I introduce myself to this forum I did say that I was still learning how this form operates. I do have a question for you though, did you say what you said out of arrogance or were you just try to let me know? It sounds more like arrogance because, if you read what I said I was never recommending a person to use baking soda to gather whatever material that they were trying to gather out a solution. Maybe you should fully read before responding how you did.

Also, thank you for welcoming me, In your back handed way! 😊😉
 
It was not of malice or arrogance.
This is chemistry and one letter may lead you from safe to in danger, so it is paramount that one is correct in regards to the terms.
And you told him to Neutralise with Sulfamic acid which is the wrong term.
We destroy/convert the Nitric to Sulfuric acid by using hot Sulfamic acid.
Some push the pH up a notch before precipitating the Gold. It is not necessary and there is always the risk of pushing too hard so end up in Neutral area. Then the most used precipitation methods don’t work well.

I have never seen the term Tiffany Blue used in refining.

The most common Silver salt is SilverNitrate which is colourless, Copper nitrate on the other hand has a rather beautiful blue colour.

Have you read C.M. Hoke’s book yourself?

Again Welcome🤓😏

I don’t think there are many things in recovery and refining that has not been debated in detail in here.

So get acquainted with that search button😀
 
Come to think about it, I can respond to whatever I want to respond to. It doesn’t matter what year it was. Someone else might think what I said is helpful or, someone might not as you did. 😉

Actually this is absolutely true. It often has the effect of opening up an old thread which is otherwise hard to find and can potentially expose some hidden “gems”. Some of our best information is tucked away in old threads so opening them doesn’t hurt anyone and, even though it won’t help the original poster, it can be educational.

Welcome to the forum.
 
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