hcl/p then hcl/cl get salts???

[crudpuppy]

I keep ending up with a large amount of these "salt" looking things forming during my hcl/cl stage what is this clearish best I can desibe is salt looking stuff? Also am I doing something wrong to form it? Is there a easy way to elimante it as it clogs filters bad! making the filtration portions very slow and annoying!

 

[martyn111]

What are you trying to dissolve with your hcl/cl?

 

[crudpuppy]

why the results of the hcl/peroxide after cleaning with hcl of cource...should be gold dissolving...hehe

 

[crudpuppy]

I believe I am having NaCl and it may be due to addition of too much clorox? basically need to reduce my clorox to hcl mixture? should form less salt and make pores easier?

 

[lazersteve]

Yes, it is most likely salt (NaCl) and it dissolves in water.

Steve

 

[Sharding757]

I seem to have gotten the same thing. I used the ap method on a batch of fingers about 250grams. Washed the the gold in boiling water after the ap process and decanted. The hcl/chlorine dissolved the foils leaving behind some solder mask bits however this white salt has formed. If this is indeed just water soluble salt, should it be removed during filtering prior to adding 3x the volume of the hcl/cl solution with water? Or doesnt it make any difference?

 

[niteliteone]

Just add a little heat (not much) and a little water, then stir. The salt will re-dissolve back into solution, then proceed as normal.
The salt is just a normal reaction of adding a strong base to a strong acid, where both are products of the same type of salt, NaCl.

 

[Sharding757]

Thank you! I thought I had a mishap of some sort. I did my research and heard of salts but mainly iron and copper ones, then did a search and ran across this. I wasnt completely sure. I figured id ask rather than go it alone and do the wrong thing on my first attempt. Still learning. There's nothing like hands on training! I did add the Clorox sparingly, was it still too much that causes this where the HCL is used up causing the salts? Just wondering for future reference. But many thanks

 

[niteliteone]

It happens to me every time I add bleach to HCl.
From what little I understand of the chemistry at this time, it is the sudden release of the chlorine from the bleach that causes the salt (NaCl) to come out of solution.
I have watched the salt form each time I add more bleach. Actually I don't remember ever adding the bleach with-out making the salt.
From what you have described happening to you, it seems completely normal as per my experiences with the mixture.

 

[butcher]

Bleach, sodium hypochlorite NaClO, one way it is made is by electrolysis of a NaCl salt water brine, where the products are chlorine gas and sodium hydroxide, mixing the caustic soda or sodium hydroxide with the chlorine gas we get bleach or sodium hypochlorite, and salt water:

2NaOH (aq) + Cl2 (g) --> NaClO + NaCl + H2O

The bleach is very basic ( opposite of an acid), (with a pH of somewhere around 12.5) (almost as caustic as sodium hydroxide lye), the opposite of an acid and as we know when we mix an acid with a base we end up with a salt of these two, just like when we mix a metal with an acid we get a salt of that metal.
This and the fact that a component of bleach is salt NaCl and sodium hydroxide (lye) it is no wonder we get salts when mixed with acid, this and the fact of mixing bleach with acid will also make salt NaCl, water and chlorine gas:

2HCl + NaClO --> NaCl + H2O + Cl2 (g)

Note; here also the basic sodium hypochlorite, neutralizes or hydrochloric acid making it into salt water.

With gold in solution, we can attack the gold with the chlorine gas in this solution:

2Au + 3Cl2 --> 2AuCl3
Au + 3HCl + NaClO --> HAuCl3 + NaCl + H2O

Heating a solution of sodium hypochlorite will also form another salt of NaCl and sodium chlorate.
3NaClO --(heat) --> NaClO3 + 2NaCl

With all of the sodium (metal ions) and chlorides, this and from the acid and the caustic bleach solution and the reactions involved it is no doubt it is going to give you the white salt in the bottom of your vessel.

 

[Pantherlikher]

Love this forum.
My light bulb just went bright for an instant.

I was washing gold from alot of glassware 1 bright warmy day and after alot of dissolving, the reaction stopped, so I carefully added more bleach. This worked but only for a short time. Added alittle bit more and there was no reaction on the gold with alot of white stuff, salt.

I just moved the solution to the drop container and used new solutions to finish dissolving. Now I know why it happened. I neutrilized the acid with bleach and started making salt.

This mix might have been close to 50/50 when everything stopped and salt was formed and noticible. Total volume of solution was 2 cups or so which wasn't much for what I was doing. But when I thought about it, I realized I added to much bleach. But I didn't think through why that is a problem.

The time it took for anything to drop was endless, like 2 weeks. I doubled volume with rinse water, warmed it for 2 hours and added SMB expecting the usual 2 days resting and everything "usually" drops by then.

I did several other batches and just watched and warmed this batch to see no reaction. I asked here about this which replies said about the CL not dissipating out. Heat, add some water and sunlight were responces.

Adding some HCL would drop the PH which would help the drop but would need time and heat to remove excess Chlorine right?

B.S.
... I need to learn to make shorted descriptions before adding my 2 copper clad metals...

 

[dannlee]

Just some notes on bleach, or why it may pay to purchase the premium brand of laundry bleach...

They use Sodium hydroxide <1% to better keep sodium hypochlorite in solution - the molar balance is preset to allow 'some' water evaporation over time but as soon as bleach is diluted the preservative effect fails, after a couple of days or weeks a 50% or 33% strength bleach-water will appear more like tap water if not in a tightly sealed container - we use a hand sprayer for disinfecting household things and have to mix a new batch every week. Bleach potency expires too - check for most recent product dates when you purchase it and buy fresh as it / before it approaches the 'expiration' date.

Also - I've seen over the years that the main reason for selecting a premium brand of bleach for laundry etc. may have a bearing on our HCl + NaClO refining, just as using a bargain brand Muriatic might - the cheapest brands have a higher dissolved PPM count of metals, and in particular, Iron. And the range of allowed contaminates varies from batch to batch or across suppliers. Anyhow, an off-brand bleach that has been sitting a while and has some water evaporated off will have both high hydroxide and iron/metals content - and a low hypochlorite strength. All thing an enemy of nearly 'lossless' precious metals extraction...

 

[joubjonn]

I have done a few drops with HCl/Cl and never had the problem seen above. just got the cheap Kroger bleach for a dollar a gallon. just did a nice batch of black powder from a cell. no issues.

 

[niteliteone]

Thanks for the follow guys 8)

 

[bswartzwelder]

You say you just did a nice batch from a cell. It was my understanding the black powder from the cell was gold and all you needed to do to it was boil in HCl three times, then boil in distilled water three times. What purpose is served by re-dissolving the black powder and then re-precipitating it? I was under the impression that the gold from a cell is already relatively free from other contaminants.

Now that the weather is getting nice, I plan on using my cell for the first time in the near future.

 

[Anonymous]

It happens to me every time I add bleach to HCl.
From what little I understand of the chemistry at this time, it is the sudden release of the chlorine from the bleach that causes the salt (NaCl) to come out of solution.
I have watched the salt form each time I add more bleach. Actually I don't remember ever adding the bleach with-out making the salt.
From what you have described happening to you, it seems completely normal as per my experiences with the mixture.

If you dilute the acid slightly before adding the bleach it stops it happening mate.

 

[steyr223]

Bswartzwelder

I guess you could melt the slimes or even the foils after ap
But then thats in the revovery section not the refining

As harold always says amongst others you can always
Try to get a nugget after recovery and if it is successful
It would be probably be mid 90% (maybe higher with your washes) but we are here as refiners not recoverers.

I really have no voice in this as i believe if i could melt 1lb of 25% au foil and get paid for 4oz i would

unfortunately that occurrence has only presented itself maybe twice in my life for all the other times I refine everything as it's more of a hobby than for money

If u I have never tried to refine your slimes from your cell you should, it's so simple you could do it blindfolded
As u said the slimes are usually clean

Thanks steyr223 rob