HCL - clorox

[Anonymous]

Will the HCL - Clorox reaction work with palladium?

 

[Irons]

Will the HCL - Clorox reaction work with palladium?

Yes.

 

[arthur kierski]

will hcl-clorox work with platinum?

 

[Irons]

will hcl-clorox work with platinum?

Very slowly but HCl/Cl is used commercially to extract PGMs from ore. It might take a year and you might not get it all but it's cheap and simple.

 

[SilverNitrate]

I want to know, because I haven't tried it... Will HCL and pool chlorine (Chlorox bleach) mix dissolve near pure gold? and what is an approximate ratio? e.g. 1liter for 2ounce @ 4HCl:1Cl?

 

[phoenix_phx_]

I will add my question too, if I can. Are we use max concentrated HCl?

And after dissolving can I use FeSO4 *H2O to extract gold? I don't have SMB

 

[Kalf999]

I will add my question too, if I can. Are we use max concentrated HCl?

And after dissolving can I use FeSO4 *H2O to extract gold? I don't have SMB

Nice question : I have dissolved some gold from plated material in a 1:1 10% Hydrochloroc acid/3% NaOCl (Glorox)

How can I get my gold out of there without SMB...?

 

[Harold_V]

I see no one has answered the question.

While I have no experience with the work-arounds of dissolving gold, I'm of the opinion that ferrous sulfate will precipitate gold. It's a great choice when working with AR, for sure.

Luckily, it's one of the precipitants that should be available without too much trouble. Garden stores should carry it as an iron supplement. Buy a small container and give it a go. The crystals in the container should be a pale green/white color. If they are brown, they won't work. Exposure to enough moisture reduces them, and they turn brown in the process. An ounce of ferrous sulfate will precipitate an ounce of gold. Dissolve the crystals in water and add a few drops of HCl to clarify the solution. Pour the ferrous sulfate into the gold chloride solution for an instant and complete reaction.

It might be a kindness for anyone trying the method to report, so others will benefit.

Harold

 

[eagle2]

You can use concd HCl or half HCl and half water. Use a minimum of bleach. Clorox with no additives is OK. See Steves tutorials.

I had a very experienced chemist friend who used Ferrous Sulfate exclusively with very good success. The only problem is that Iron contaminates the precipitation. You have difficulty washing it or you will have to re-precip. with another reagent. Ferrous will also precip. Palladium at the same time.

Al

 

[Harold_V]

Ferrous will also precip. Palladium at the same time.

Al

I'm not convinced it precipitates palladium, although I stand to be corrected if I'm wrong. I'm of the opinion it is simply dragged down, but does so far easier than do other elements.

I noticed that the gold that came down from palladium laden solutions was always quite dark. I used ferrous sulfate to selectively precipitate gold from such solutions on a fairly regular basis when I first refined due to the presence of dental gold in my accumulated materials.

Palladium tends to drag down with SO2 as well, and I don't think it is truly being precipitated. I don't recall having the same problem with platinum----just palladium. It is also quite difficult to wash from the precipitated gold.

I wonder if Lou has an opinion.

As far as ferrous sulfate being used for precipitating gold, I found it was very easy to eliminate in washing---although I was a wash freak and went far out of my way to wash well. In spite of that, I quit using it and started using SO2 from a cylinder. It's much faster and easier.

Harold

 

[Irons]

Some reducing agents can reduce PGMs as well as Gold.

Some literature I read recommended using Oxalic Acid because it is a milder reducing agent and usually won't reduce PGMs. Success will vary depending on what's in the mix.

I know that Sodium Sulfite will reduce PGMs, but slowly.

 

[lazersteve]

From what I've read in literature concerning SO2 and Palladium, it will precipitate from solutions of the nitrates. The whole chemistry changes for some precipitants when the PGMs are in nitrate or sulfate form. This would explain why you want to drive off the nitrates before moving to precipitation.

Steve

 

[Irons]

Some literature from 1887 that discusses this issue:

http://tinyurl.com/65sf46

The perpetual reinvention of the wheel. 8)

 

[eagle2]

Lol. Lots of comments. My Merck Index says Palladium Nitrate is soluble in water with turbidity. With much water it precipitates as a brown basic salt. Also completely soluble in dilute Nitric acid.

With such varying characteristics it might do many things. but I tend to think also with Harold, its mostly dragged down with other metals or by varying solution conditions. So I stand corrected.

I would buy my friends Gold at 10 to 20gms at a time. My precips would come out yellow-brown. His precips. looked just brown. I would try to purify them with Ammonia and HCl washes. I even would boil the precip with concd. HCl and it still wouldn`t look good. I don`t think he washed them at all. When I re-dissolved them and re-preciped with Sodium Nitrite I had lost about 6-10% of the weight. When I analyzed the leftovers, they mostly where Palladium, Iron and some Nickel and Copper.

I asked him where did all the Pd come from? He said he wasn`t sure, he had not had any dental stuff. I asked him why do you use Ferrous? He said its very easy, quantitative and he can neutralize the AR with Ammonia!! Well I tried Ferrous, but didn`t like the Iron that was in the Gold precip. and at that time I was exclusively into Sodium Nitrite.

I never tried a dual experiment where you would compare Gold yields from standard methods and a method of neutralizing with Ammonia. No book I ever saw ever commented on it, except to vaguely infer its a no-no.

Sodium Nitrite will definitely separate Gold from the PGM`s.

Al

 

[eagle2]

Irons, very interesting reference. That chemist seems to never have tried Sodium Nitrite or it was before his time!.

Al

 

[Harold_V]

I never tried a dual experiment where you would compare Gold yields from standard methods and a method of neutralizing with Ammonia. No book I ever saw ever commented on it, except to vaguely infer its a no-no.

One of the things I learned early on is that there are compounds of precious metals that are extremely explosive. Some so much so that they are known to exist in theory only.

Armed with that idea, and not being a chemist, I was faithful to follow well documented processes (Hoke's book, in fact) and stayed away from experimenting. I never thought I was clever, didn't think I could revolutionize the refining industry, and had only one objective in mind. To refine precious metals (starting with gold). I could see no reason to re-invent the wheel-----finding it sufficiently round for my purpose.

Having stated the above, the idea of using ammonia, or anything that is not commonly recommended, in a gold solution, frankly, scares the hell out of me. I always recommend folks stick to tried and proven methods unless they know what they're doing.

Harold

 

[Irons]

Irons, very interesting reference. That chemist seems to never have tried Sodium Nitrite or it was before his time!.

Al

Sodium Nitrite was known long before his time but the interaction with PGMs might not have been understood.
Working with PGMs is more of an art than science, as you know, and he surely knew a lot more than he was willing to write about. Refiners have their secret formulas and techniques, especially those who work with PGMs.

 

[eagle2]

Yes, it`s an art. I had a very small amount of Pt I was recovering. I thought it was all out. A week later there was more at the bottom of the beaker and the solution color still looks Orange. Its all fun.

Al

 

[Irons]

Yes, it`s an art. I had a very small amount of Pt I was recovering. I thought it was all out. A week later there was more at the bottom of the beaker and the solution color still looks Orange. Its all fun.

Al

Orange is good, especially when it tends to the red side. 8)

When it quits being fun, it's time to find another way to entertain ones self.

 

[GeeDub]

The crystals in the container should be a pale green/white color. If they are brown, they won't work.

Well you just solved a 30 year old mystery for me.
In my early years of refining, I tried Ferrous sulfate to drop the gold, on the recommendation of an independent assayer I knew.
Didn't work at all.
Couldn't figure out why, and I was surprised because I had been told it was easier than the Sodium Bisulfite I had been using.
The crystals were yellowish and brown.