# Cannot precipitate gold from HCL and bleach



## DaveinLangley

Hello! I am posting this at my own risk and will remove myself from the forum if I'm found to be a problem. I have just started processing gold and have read through Hokes book. I have successfully recovered gold from computer bits and pieces. My problem is that I dissolved gold from plates and cups in HCL and bleach but cannot precipitate it with sodium metabisulfite. Yes, there is gold in my solution. I have read through the forum and found that I may have used too much bleach and that I should heat it to remove the excess bleach. I have done this but still no results. The SMB fizzes and drops to the bottom of my solution. If anyone can help it would be greatly appreciated and I will be happy to help others as I learn the process. I believe forums are for people to help others and hopefully to save them from having to go through the lengthy processes that I go through. I am one who helps others by spending numerous hours researching and experimenting and then passing on my knowledge to them. Thanks, Dave


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## butcher

Dave,
Everyone here is glad to help those who do study and are trying to learn.
We don't have a problem answering a few questions as long as you working to learn.

There can be more than one problem of using too much bleach, the bleach is basic (opposite of an acid) it will turn some of your HCl into salt sodium chloride NaCl, the bleach sodium hypochlorite is made basic with sodium hydroxide NaOH, to keep the chlorine in solution, when you mix it with HCl acid some of the acid is consumed, neutralized by the sodium hydroxide in solution, as the acid converts the hypochlorite to chlorine gas, the bleach being mostly water (over 90%) dilutes this solution keeping most of the salt NaCl dissolved, until you go to heat and or evaporate solution, where you can begin to have much the sodium metal salt form a white precipitant.

It is possible that you can use so much bleach that you basically, destroy all of the HCl acid and actually just make a basic hypochlorite and salt solution in water.

Heat will drive off the chlorine gas, but can also concentrate solution, so if you have to add much heat you may want to dilute it afterwards to redissolve the salts.

You can test to see if your solution still contains chlorine, heat it until vapors come off of your solution, fill the cap off of a bottle of ammonia about half full (the ammonia will have a clear fumes you can smell), hold the capful of ammonia in the path of the fumes leaving your heated solution, let the two fumes mix, if the clear fumes from both mixtures form a white cloud of fumes when mixed, it proves chlorine gas in your solution, the white cloud is made when clear chlorine fumes and the clear ammonia fumes combine to form the white cloud of ammonium chloride gas.

The gold from cups, plates and dishes is normally very thin (like gold with other objects it can look like a lot more than there is, sometimes you can hold the glass up to the sun and see through the gold plating which sometimes looks green, it takes quite a bit of glassware to get much gold, basically what I am trying to say is you may not have as much gold as you think, sometimes with very little gold in solution, you can miss the small amount of fine brown powder even after it precipitates, I do not now how much glassware you processed, or how much gold you may or may not have in solution.

Have you done a stannous chloride test prior to adding SMB?
This can be an indicator of not only gold in solution, but also if the gold can easily be reduced with a chemical precipitant like SMB, too much oxidizer the gold will not easily be reduced, or can easily redissolve again when trying, sometimes you can watch the gold dissolve even in the stannous chloride test if the oxidizer is still there and not terribly strong,..


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## Pantherlikher

Hello and welcome.
I was going to do the normal "newbie" type reply but washing dishes for gold is I think the easiest but time consuming thing to do.

First, read up on how to dispose of spent solutions so you can be ready on that end. I put everything into crock pot #1 which has copper in to drop any PM. Then move it along my waste stream of crock pots until I raise Ph while evaporating.

I have done allot of dish washing since I get tons for free.
Patience is key here. First get a PH test kit to make sure the solution stays acidic. My big mistake was too much bleach causing high PH.
That solution took 2 weeks to drop gold. Yes, I wanted to see if it would drop. 2 weeks it took sitting on the shelf.

Normally pouring a little bleach into HCL, a little at a time since you are pouring high PH into acid making violent reaction, will dissolve gold quickly at first. Then slowing down making you think you need more bleach. This is ok but you need to measure how much bleach you are putting in there. The indicator of too much bleach is white salts forming and no more dissolving of gold.

Just remember, there is hardly any gold in the first place so don't expect much from just a handful of glassware. I have washed gold from well over 100 pieces and barely have a couple grams to refine.

I will use just enough HCL to stand plates in the container and just cover the gold trim. Then I'll add a small splash, maybe half a ml of bleach at a time. Using a suction bulb, I will splash carefully over gold that is above the solution. When the reaction slows, add a little more bleach. I do this until the mix is about 3 to 1. That about becomes to much bleach.

When the gold is dissolved, I move the glass to the rinsing basin. Large plastic container where I spray water to rinse solution off. This accumulates allot of water. I am thinking here is where the problem gets worse with PH.

So far, I have added twice the volume water to the solution, careful acid to water only. This would increase the PH more. If my thinking be correct, test PH as well as for gold. Add HCL to lower PH. Now add heat and/ or place in sunlight until patience runs out. As long as you can. Add only a small amount of SMB and continue heat, sunlight, and add allot more patience. It will drop but will take time. Do another batch while waiting.

The excess water from rinses needs to be evaporated for concentration. Here is where a coffee pot on heat works but slowly. I am kicking around using solar energy to evaporate. Magnifying glass type heat collector for the hotplate. 

After something drops from solutions, I will decant and put solution into a tall glass and let sit for as long as possible. Week or so as more will precipitate and settle.

Eventually you will have allot of rinse water to drop what ever it holds. Add HCL to drop PH to acidic and add SMB and wait with sunlight and/ or heat. You need to wait for chlorine to dissipate out being careful of fumes the whole time!

I have an enclosed shed with a fan blowing in the window behind me and everything next to the exit window in front of me. I made the mistake once of leaving the door next to me open. I poured HCL into the container and just as I put the cap back onto the bottle, the wave of chlorine gas hit me like a brick. I breath very shallow when doing all of this as a precaution but even a small breadth of gas will cause violent coughing and hard breathing! Once is all it takes to remind you of how dangerous this can be. I managed to stumble outside to fresh air and hacked half a lung up for about 10-15 minutes until I could breath right. Imagine not having an escape plan would do! Getting the expensive gas mask to prevent this is out for me right now but soon. When the door is closed and fan running, you only smell a hint of chlorine outside the exit window. No more then the smell from my pool when I add shock so it dissipates with air as it exits the shed.

All of this is will produce something. The amount depends on how much you process. Like I said, I washed over 100+ pieces of glassware and barely have anything to show for it. Is it worth the effort. Hmm... how many tons of material do miners move and process to get that gram of gold? And how much work involved? Here, you are only washing allot of glassware which makes the hazard of boredom grow causing you to become careless which can lead to an "accident" as people have termed carelessness.

I hope I have helped you visualize what you are doing and have added the most important ingredient necessary for good results, PATIENCE.

Please add where you think fit to help, correct anything my memory may have gotten wrong.

B.S.


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## butcher

Pantherlikher, 
I think you have done a very good job explaining this, and you went into good detail of the pH of the solution, which can become a very important factor when using sodium hypochlorite, especially with washing dishes where you can very easily use way too much basic bleach solution, basically destroying the acid, and keeping the gold locked up in a hypochlorite solution...


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## DaveinLangley

Thanks for your replies! I'll try your suggestions and let you know how it goes


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## Gratilla

Bear in mind that sodium hypochlorite is also an oxidizing agent. All acid side leaches need BOTH an acid (for low pH) and an oxidizing agent (for high Eh) in order to dissolve gold. Exact conditions can be determined from a relevant Porbaix Diagram, which plots Eh against pH. See SSN.pdf, available for download on the forum. For gold, this shows a minimum Eh of around 820mV required over a pH range of around 0 - 4.2.

Some oxidizing agents can be quite persistent. Nitric acid is a good example and there are many posts on the forum dealing with that problem.


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## solar_plasma

Now, this is the information jewel of the day to me! Thank you, Gratilla! I wouldn't have thought, the ssn.pdf document could be of any use for getting more understanding about the HCl/hypochlorite method, now I see.


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## fizzie

hello my name fizzie,im new here,anyone can help me?I dont know y I cannot precipitate gold from my hcl+bleach...I just separated the pins gold from electronic board such as computer...when I add bleach into hcl acid turn green dark..after that no powder coming out.tomorrow it seem like a little bit of dark salt in the bottom...what should I do now?? Plss


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## g_axelsson

Hi fizzie, to be able to help you we need more information. Write down step by step what you have done, what chemicals you used and how much you used. We also need to know if you have done any tests, for example with stannous chloride and if there is any metals left undissolved. Don't leave out steps like filtering or diluting.

Göran


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## Pteranadon

I too have dissolved some recovered foils in hcl-cl and think i have used too much bleach as i can't precipitate it either but i have a ph of less than 4. My ph test only goes from 4 to 10. I'm not sure what's stopping it at the moment.....


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## lazersteve

As a side to the excellent replies and suggestions already given I would like to remind those of you making HCl-Cl with muriatic acid (HCl) and bleach (any hypochlorite salt or solution) that you can use 35% hydrogen peroxide in place of your bleach and achieve much cleaner and virtually salt free reactions. 

When using high strength peroxide observe all safety precautions and add very small amounts of peroxide with constant stirring.

Steve


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## Kreis412

Am i to understand that if i add too much bleach i am actually diluting the hcl?


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## FrugalRefiner

Yes, diluting and also neutralizing.

Sodium hypochlorite doesn't really like to stay in solution. To extend the shelf life of the bleach, sodium hydroxide is added. The sodium hydroxide will react with the HCl, and the high volume of water will dilute it.

Dave


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## Geo

To add to what Dave said, sodium hypochlorite is a base. It comes from the manufacturing plant at a PH factor of 12. You will need an excess of HCl for the dissolution and precipitation to work right.


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## dervishh

You guys are awesome! I hope I'm able to find such great help if I run into an issue!


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## Martijn

fizzie said:


> hello my name fizzie,im new here,anyone can help me?I dont know y I cannot precipitate gold from my hcl+bleach...I just separated the pins gold from electronic board such as computer...when I add bleach into hcl acid turn green dark..after that no powder coming out.tomorrow it seem like a little bit of dark salt in the bottom...what should I do now?? Plss


Did everything dissolve? If not, your gold has probably cemented out on the base metals of the pins.


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## Yggdrasil

Martijn said:


> Did everything dissolve? If not, your gold has probably cemented out on the base metals of the pins.


The post you are replying to is from 2017


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## ssmontecarlo

I recently removed gold from plates and other items. Like small tea set, figurines, etc.

I had a small amount of gold that I precipitated out of some ram card filters. Maybe a tenth. I poured that into the beaker of solution from the plates and other stuff. Let it set over night, the solution was clear. And there was a little more gold, but not alot. I've learned. It takes alot of material to recover gold from, to get a return.


DaveinLangley said:


> Thanks for your replies! I'll try your suggestions and let you know how it go


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## chrundle_the_great

lazersteve said:


> As a side to the excellent replies and suggestions already given I would like to remind those of you making HCl-Cl with muriatic acid (HCl) and bleach (any hypochlorite salt or solution) that you can use 35% hydrogen peroxide in place of your bleach and achieve much cleaner and virtually salt free reactions.
> 
> When using high strength peroxide observe all safety precautions and add very small amounts of peroxide with constant stirring.
> 
> Steve


When using peroxide do you still use SMB to drop the gold?


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## Yggdrasil

chrundle_the_great said:


> When using peroxide do you still use SMB to drop the gold?


Yes, the important thing is that it is sufficiently acidic.
For HCl Peroxide that is no problem, but if you use bleach, it is a thing to keep in mind.
Check the pH, it should be around 2 ish.


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