# pd failed to drop



## JHS (Aug 26, 2013)

First let me say that i sent this to Harold and he reviewed it then strongly suggested I post it.
since Harold reviewed it
I ran two batches of 4t oz.
1 with the di h20 in question
and one with the original brand
both dropped no problem
so h20 is no longer an issue and all the chemicals were the same and did there job
the question is weather
i do know what needs to be done with the process
what i do not know is why it did not work on the ten beakers in question
any thoughts would be appreciated


i aquired 52 pounds of material .all of it exactly the same.
the lions share of the weight was pd. gold is minimal,with a small amount of copper.

i started with a 4000 ml beaker added 1000ml di h20
then placed one pound exactly of material in the beaker
i then began adding 69.5% nitric at 100ml incriments to 1000ml as the reaction slowed 
at the end,equal to 50-50 mix.
at the end of the reaction,i then filtered the solution.
then dropped the pd without a hitch.
the second batch went exactly the same way.
no problem.
i then set up 10 batches and again no problem.
i then set up 10 more,the exact way.
i got nothing to drop.
here are the variables
on the first 12 batches
the weather was about 70 degreese and about 65 at night,we had a low pressure system sitting over head for the entire week.with strong thunder storms with a highly electrically charged atmosphere
the batch of ten IN QUESTION
the temperature rose to near 99 degreese with a high pressure system in place.

thanks john


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## lazersteve (Aug 26, 2013)

Was the source material a mix of SMD devices? The reason I ask is because not all SMD devices contain Pd. Just because the components are all mixed together does not mean that they are all the same. 

How well were the samples mixed before you set up the 10 sample runs?

If your source material was all identical part numbers then I'm at a loss to explain your results aside from a possible mix up with your reagents. 

Steve


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## JHS (Aug 26, 2013)

Hi Steve,
the material was 100% exactly the same.
absolutly nothing different.
john
p.s. the tests i did yesterday was under a low pressure system.


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## FrugalRefiner (Aug 26, 2013)

I just want to make sure I understand what you've done, so let me restate it to make sure I've got it.

You had 52 pounds of material that was the same.

It sounds like you did some small test batches of 4 ounces each with a couple of different brands of water, but since all went well, you've determined that the brand of water is not an issue.

Then you scaled up a bit and did a test batch of one pound of material in 1,000 ml of H2O and 1,000 ml of concentrated nitric, adding the nitric in 100 ml increments. You precipitated the palladium with no problem (Let us know how you precipitated, please). You ran another batch, just like the first, and it also ran as expected.

Then you ran 10 more batches, exactly the same, and they all reacted the same.

Then you ran 10 more batches, but they all failed to precipitate?

I just want to make sure I have all that right.

It's hard to believe that barometric pressure or atmospheric electrical charge would affect the reaction to that degree. Temperature, maybe.

I think the first question is how did you try to precipitate the palladium? Was the precipitant from the same container as used for the first batches that were successful? Did you get any precipitate at all from the 10 in question? Have you tried to cement a batch with copper?

I know, more questions than answers. :| 

Dave


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## JHS (Aug 26, 2013)

Hi Dave
actually the first two batches were the one pound batches.
the two 4 oz batches were the last ones,they were a test to see that the h20
was not the cause.the chemicals were, and are all the same,and worked yesterday the same as two months ago
Dave,I do know how to proceed with the solution.that is not a problem.
what i do not know is why it happened.
thanks john
p.s. nothing at all droped.tests show it is all still in solution.
but the real question is what conditions could have effected all ten.
low pressure cause atoms to move faster but colder tempurature slows them.
high pressure slows atoms but but hotter temprature speed them up.
the low pressure was from the toranados in oklahoma that killed so many
the high pressure was the following week.


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## g_axelsson (Aug 26, 2013)

As a physicist I must protest! The speed of an atom is basically the same thing as the temperature.
Low or high pressure doesn't matter at all.

And you have still not told us what you use to precipitate palladium.

Göran


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## FrugalRefiner (Aug 26, 2013)

John,

Thanks for the clarification. I won't try to spend any time solving a problem you don't have. 8) 

You haven't mentioned how you were precipitating the palladium. That may help the experts.

As for what conditions that might have caused the anomalous result you had... Lou? Freechemist? ...

Interesting question.

Dave


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## JHS (Aug 26, 2013)

Goran
i am not a physicist,i had to copy physicis to get the spelling correct.that was my mind using what seemed logical.
i stand corrected.
not that it should matter in this question
but it is
ammonium chloride
but as i said all factors were exactly the same from start to finnish.
except those ten did not drop.
thanks john


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## JHS (Aug 26, 2013)

Dave,
i just poured off 200ml i dropped it with zinc.
as i said the pd is still in solution.
it was never a question of process,it's a question of why.
thanks john


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## Platdigger (Aug 26, 2013)

Well, with out understanding exactly what you did, it is hard for anyone to speculate on the why.
What did you use besides (or after) the ammonium chloride?


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## JHS (Aug 26, 2013)

Hi Platdigger
nothing else
every thing was as already discribed.
like i said, it is not the cure i seek
it's the why.
thanks john


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## JHS (Aug 26, 2013)

Hi everyone,
a frend on the forum pointed out that i might be coming across as a bit defensive.
that was not my intension.
so i will say i am sorry ifyou felt that way.

yesterday when i did the 2 test batches we were once again under a low pressure system.
there were no other conditions that were the same as the first sucessful batches.no rain no lightning no thunder.they went off with out a hitch.
tomorrow conditions are predicted to be closer to the high pressure system that was in place when the ten failed.it is not a huge high pressure system like the one that followed the tornados,but maby it will be close enough.
temperature are predicted to reach 100,that would be one degree higher.that 1 degree should not make any differance.
so i will run another 4 oz batch to see if i can eliminate some of the conditions.
i still have more than enough of the same chemicals i started with,so everything should be the same.
thanks john


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## Harold_V (Aug 27, 2013)

My question would be why you have achieved success using ammonium chloride. Sure, it's part of the procedure, but it, in and of itself, isn't supposed to precipitate palladium. 

Over the many years I processed, I recovered about 70 ounces of palladium. I can't think of even one instance where I did not use ammonium chloride, then the solution was heated near boiling, and sodium chlorate introduced a few granules at a time. That resulted in the formation of the familiar red material we associate with palladium. 

I learned, very early on, that the platinum metals do not precipitate from dilute solutions, nor do they normally fully precipitate. It's all in Hoke, including the use of sodium chlorate. 

What am I missing?

Harold


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## solar_plasma (Aug 27, 2013)

When you say pressure, how many milliBar are we talking about?

High pressure AND high temperature both affect the solubility. At least the solubility of gasses. I do not know the process that well, but I always read, that the NH4Cl solution has to be saturated. If the solution was made under colder temperature, it will not be saturated under high temperature anymore. I guess the temperature has the highest effect, though I don't know, how extreme your pressure systems are. At lower temperatures the same solution would be saturated again.


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## Platdigger (Aug 27, 2013)

Harold_V said:


> My question would be why you have achieved success using ammonium chloride. Sure, it's part of the procedure, but it, in and of itself, isn't supposed to precipitate palladium.



My point exactly. When I did this from a nitric solution, I diluted first, then ammonium chloride, then chlorox (in lieu of sodium chlorate) and obtained the red palladium powder.
So, you are saying that most of the time you obtained a precip of palladium from a solution there of, with ammonium chloride only.
Yes?


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## JHS (Aug 27, 2013)

Gentlemen,
perhaps i stated my question in correctly.
the procedure i used worked,except the one in question..
lets suppose that the procedure was done correctly since the same procedure worked as recently as this past sunday on the 2 four oz.tests.

I suppose the question should have been,
How does, or could, atmospheric conditons and temperature affect the procedure?
thanks john


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## jimdoc (Aug 27, 2013)

JHS said:


> Gentlemen,
> perhaps i stated my question in correctly.
> the procedure i used worked,except the one in question..
> lets suppose that the procedure was done correctly since the same procedure worked as recently as this past sunday on the 2 four oz.tests.
> ...



Where did you learn the procedure that you are using?

Jim


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## arthur kierski (Aug 27, 2013)

nitric solutions containing pd precipitates pd with nh4cl-----i did this one or two times and it worked---recently one of the members( i do not remember who) wrote a thread about this topic
Platdigger---when you precipitates red pd salts with clorox +nh4cl,first add clorox and then nh4cl-----if you add first nh4cl and then clorox,you might have a big explosion----this explosion happened with me and almost blinded my son---this happened about 10years ago----
JHS----i really do not know if weather conditions affects pd precipitation
thanks and regards to all
Arthur


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## JHS (Aug 27, 2013)

Thank you arthur.i know it does because i have done it countless times.it can also be done in an ar solution and it will begin dropping within 30 minutes.done that too.
john


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## JHS (Aug 27, 2013)

When you say pressure, how many milliBar are we talking about.

i can not answer that question.i do not know.
but it was a huge low,followed by an equally massave high.enough to change the temperatyre by 30 degreese from 70 overnight.
and then hold temperature change to 100+- 1 degree for 15 days.
thanks john


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## solar_plasma (Aug 27, 2013)

Did you make a fresh saturated NH4Cl solution each time or did you make it, when it was cold weater and used the same solution, when it was hot?


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## JHS (Aug 27, 2013)

Solar_plasma, how did you get so smart?
I think that you have found the root cause of the problem.i made it when it was cold,and used it when it was hot.
So i think we can conclude that the temperature had an effect.
this was precicely what i was looking to find out.
so i will make it in cold weather for cold conditions
and in hot weather for hot conditions.
the last 2 small batches i made it the same day,and that is likely why it worked.
you get an A+
thank you so much.
john


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## solar_plasma (Aug 27, 2013)

Sir, too easy, sir! Next question... 8)


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## JHS (Aug 27, 2013)

Ok,you asked for it.
after my wife went through menapause,she decided she was not going to be the sweet little girl i married.
she the then became grouchy and critical of everything and everyone,except me.
however recently it has turned tword me as well.
my question is what can i do to change that.
i have tried new cars jewlery and flowers.
none of whitch has more than a temporary effect.
try that one.
lol john


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## solar_plasma (Aug 27, 2013)

Women are stopping to produce estrogen, when they become older. This is one reason for


> irregular menses, vasomotor instability (hot flashes and night sweats), atrophy of genitourinary tissue, increased stress, breast tenderness, vaginal dryness, forgetfulness,* mood changes*, and in certain cases osteoporosis and/or heart disease.


 wikipedia

She could talk with her doc about getting hormones. This would also avoid the other possible problems.

Sir, too easy, sir!


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## JHS (Aug 27, 2013)

she is way past hormones,this was an announced concious decision,many years ago.
she simpely stated she was tired of being nice and announced she was going to become a b
i will not finnish that word.
john


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## solar_plasma (Aug 27, 2013)

If I was a woman after menopause, I would take hormones to avoid all those problems.

But ok, it could also be an internal reason, especially, if she feels, that she all her life has been too nice and always like other people wanted her to be.

Well, if nothing else, drink one (1!) beer! Will it change her? - No, but you feel better with the situation. 8)


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## JHS (Aug 27, 2013)

I do hope you know i was just kidding. we got married when we were kids,and we will die together.
john


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## solar_plasma (Aug 27, 2013)

I am kidding too, when I tell someone, to drink alkohol. :lol:


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## JHS (Aug 27, 2013)

Don't hikkupup too much or i'll post that to loose lose
lol


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## freechemist (Aug 30, 2013)

> *August 26th,5:55 pm FrugalRefiner asks:* ...You haven't mentioned how you were precipitating the palladium. That may help the experts.
> As for what conditions that might have caused the anomalous result you had... Lou? Freechemist?...



My first 2 comments on these interesting questions:
1.) It's the 3rd time now, that someone asks, what your exact procedure is. - Still not answered.
2.) There is no "anomalous result", because a "normal result" usually is one, that you don't expect.

Some quotes from the series of posts on the title-subject:


> *August, 26th,6:23 pm, John (JHS):*"....not that it should matter in this question but it is ammonium chloride..."
> 
> *August, 26th,6:53 pm John, (JHS):* "...i just poured off 200ml i dropped it with zinc. as i said the pd is still in solution. it was never a question of process,it's a question of why..."
> 
> ...



*@JHS:* This, your last cited answer indicates to me, that you really don't understand, what's going on in Pd-precipitation as the "red ammonium salt", (NH4)2PdCl6. Still insisting on your full understanding of connected processes and procedures, to me you seem to begin being lost in unscientific speculations, if not even in a certain belief in witchcraft, making the weather the culprit for your apparently erroneous results. So, let me try to clarify some things.

The keynote of this whole discussion comes from Harold, saying that besides ammonium chloride, other factors/reagents are essential in this precipitation process, too. First of all, to form the anion, [PdCl6]2-, to be precipitated with ammonium chloride, as the only sparingly soluble ammonium hexachloropalladate(IV), (NH4)2PdCl6, a lot of chloride must be present, which is not contained in your starting Pd-solution (about 1:1 conc.HNO3/H2O). In addition, an oxidant, like chlorox or sodium chlorate is needed, to oxidize Pd(II) to Pd(IV). According to my practical ecperience, chloride- and acid-concentration of the Pd-solution should be rather high, like 50 - 100 g HCl per liter, which, as far as I can judge it, is far away from chloride-concentrations in your experiments.


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## solar_plasma (Aug 30, 2013)

Fact is, after he used a saturated NH4CL solution, Pd salt precipitated like in all the other beakers before. Fact is, a salt solution, which is saturated at 0°C is not saturated anymore, when it is heated to 30°C. Fact is, all descriptions,I read, say, you have to use saturated solution. If this is witchcraft, I am a magician.



> *nitric solutions containing pd precipitates pd with nh4cl-----i did this one or two times and it worked---recently one of the members( i do not remember who) wrote a thread about this topic*
> Platdigger---when you precipitates red pd salts with clorox +nh4cl,first add clorox and then nh4cl-----if you add first nh4cl and then clorox,you might have a big explosion----this explosion happened with me and almost blinded my son---this happened about 10years ago----
> JHS----i really do not know if weather conditions affects pd precipitation
> thanks and regards to all
> Arthur



As you can see John is not the only one who had succes with this method. So, instead of saying, it cannot be, what has not to be, you could try to figure out, WHY this is working. You are the chemist! :lol: I can follow your arguments, but fact is, it works, and not only for one. I follow this discussion with great excitement, since like many others I want to do my mlcc's sooner or later, but want to understand the reactions of all possible methods, so I know, why I choose one of them.

Freechemist, you are one of our bright shining stars. Assuming, they didn't have collective hallucinations from breathing toxic fumes, what could make a precipitation or crystallizing possible, when only saturated NH4Cl is used on nitric Pd solution?


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## solar_plasma (Aug 30, 2013)

Would't nitric form AR with NH4CL with lots of free native Cl's? And where will NH4+ go? Won't it be possible, that reactions are taking place similar to when NH4OH and Chlorox is used (don't know the sequence to not to blow the vessel).

He told me, the reaction takes 30 minutes. This might be a reason, why many others aren't stumbled over, that it actually works.


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## JHS (Aug 30, 2013)

if not even in a certain belief in witchcraft

Thank you.with that I will drop out of this discussion.


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## solar_plasma (Aug 30, 2013)

Then, when and if ammonium hexachloropalladate(IV) is formed, already sparingly soluble of its own, most of the rest will be thrown out of the solution by the saturation with excess NH4+ ions?


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## solar_plasma (Aug 30, 2013)

> Thank you.with that I will drop out of this discussion.



Stay! You know, what you have seen many times. Soon, you are holding the palladium in your hands. Now, it's up to the experts and chemists to tell, why it works. They wouldn't be scientists, if they did not want to know, why it works. Does anyone know the thread:


> recently one of the members( i do not remember who) wrote a thread about this topic


?


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## JHS (Aug 30, 2013)

if not even in a certain belief in witchcraft, making the weather the culprit for your apparently erroneous results
Arthur this apparently applies to you as well.
stay,are you kidding me.accused of practing whitchcraft and lying
Harold exactly why i did not want to post in the first place.
john


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## solar_plasma (Aug 30, 2013)

That's the way scientists must feel, when they discovered something new and no one wants to publicize it, because it is against the mainstream or large industries's interest. So, you are in the best company. :lol:


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## JHS (Aug 30, 2013)

by Lazor steve
The data I compiled in the chart I posted above is from several very early chemical text that clearly states plain ammonium chloride will precipitate Pd from nitric solutions.

In Hoke she is assuming we have mixed PGM solutions, in these cases the solution is denoxxed to allow partial separation of the Pt and Pd. Since your solution is primarily Pd in nitric solution you shiould be fine with NH4Cl only. Make sure the Pd solution is very concentrated
http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=51&t=14881&start=40
http://www.bodyworkzsupply.com/pm-ar.html
the list can go on and on if you require it
this was not my original sorce,but i did read it.
i'm done


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## Platdigger (Aug 30, 2013)

After rereading that thread from Steves post on, I see what you guys are saying.
In my case this was from an all ready dilute solution of pd obtained from extracting
the pd with nitric from some aftermarket cat substrate. Of the which I diluted further
(I believe by at least twice the volume) before adding the ammonium chloride (which
also was not concentrated).
At this point there was no precip, as you may have guessed.
After adding the chlorox bright red salts were formed.

So what I am saying is, this works from "dilute" solutions.
No need to evaporate huge amounts of water.
As for the saftey of the procedure, I defer.


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## Platdigger (Aug 30, 2013)

I do believe JHS, that you could and would have saved this forum (at least this thread) a lot of
time and trouble if you would have merely explained your "procedure", in your first post.
Instead of making everyone guess what was going on.
Am I wrong here? Perhaps someone can help me out.


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## JHS (Aug 30, 2013)

If you were knowledgable of the pm between Harold and i,you would have known that he challanged the ammonium chloride working alone.I am not equipped with enough knowledge in the refining field to argue a point such as that,with a man of his knowledge.so i purposly left that out,until someone else confirmed it.
john


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## Platdigger (Aug 30, 2013)

Ok, fair enough. I challenged it as well, not remembering that thread.


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## arthur kierski (Aug 31, 2013)

the book-precious metals 1982-----from the International precious metals institute, in one of the chapters about pd,descriibes the process of precipitating red pd salt from an ar solution using only nh4cl-------

i obtained this book 25 years ago ,when i started to recuperate pgms from auto cats----

note:they do not eliminate nitric from the ar----
Thanks and regards 
Arthur


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## Harold_V (Sep 1, 2013)

arthur kierski said:


> the book-precious metals 1982-----from the International precious metals institute, in one of the chapters about pd,descriibes the process of precipitating red pd salt from an ar solution using only nh4cl-------


Arthur,
Would you further address that comment? Is precipitation accomplished at room temperature, and how much NH4Cl is recommended per ounce of value?

Interestingly, I may have that information, but it's in storage, and has been for many years. I'll have access to it in the near future, when we move to our new house. 

In my numerous experiences with palladium, I never had any precipitate without the addition of sodium chlorate, and even then it could be difficult. It was always accomplished near a boil.

Harold


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## butcher (Sep 1, 2013)

I am unsure if this fits into this discussion of palladium precipitation using ammonium chloride alone without adding sodium chlorate afterwards to precipitate palladium.

From Hokes book alternative methods Page 157:

Precipitate the gold first, using sulphur dioxide gas. 
free the aqua regia solution from excess nitric acid as usual, filter
it clear of all sediment or cloudiness, then saturate with sulphur
dioxide gas until all the gold is precipitated. The gold powder is
filtered off, washed thoroughly as usual, first with water, then with
hot hydrochloric acid, then with water again, to remove dissolved
platinum and base metals. 

The filtrate from the gold precipitation
contains base metals and the platinum-group metals. It is now thoroughly
saturated with chlorine gas for some time, in order to counteract
the reducing effect of the sulphur dioxide upon the platinum.
(This effect is one of the considerations mentioned above, which is
not easily explained to the non-chemist and about which we shall
say something in the "Questions and Answers" at the end of this
chapter.) After that, the solution is placed in an evaporating dish
and concentrated somewhat, until there is no longer an odor of
chlorine.
If ammonium chloride should be added at this point, it will precipitate
platinum as the orange powder, and most of the palladium
and iridium will come down with it. (The color of the powder
will run from pale yellow to deep maroon, depending upon the
proportions of the various metals and the temperature of the reacting
substances.)

In some cases this is a satisfactory method that is, some workers
are willing to obtain all their platinum-group metals together in
this way, and then repurify the powder as required. Other workers,
including Whitely and Dietz, vary the procedure thus: just before
adding ammonium chloride, they stir some alcohol into the hot
solution from which the chlorine gas has just been expelled. This
reduces the palladium and iridium compounds to the "ous" condi
tion, in which they stay in solution while the platinum salt comes
down. The palladium and iridium are recovered later from the
Stock Pot, as usual.

As we said above, to the non-chemist this is confusing. We have
mentioned certain "considerations" and "effects" that are difficult to
explain, and this is one of them. In the Questions and Answers at
the end of this chapter we shall discuss these more fully under the
heading of "Oxidizing and reducing effects changes of valence
'ous' and"ic"conditions."


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## arthur kierski (Sep 1, 2013)

Dear Harold; i tried twice to write an answer to you and my computer stopped working----
the article in this book goes from page 463 to 475---it was writen by a Dr. George Hoo from western elecric engineering research center-----pd is disolved in ar with heat and agitation--to the solution nh4cl is added and red ammonium hexachloropalladate is formed---then (with great details) nh4oh,is added,filtration,hcl forming yellow salt,then formic acid to form pure pd powder---
he did not specify quantities-----
As for me ,i only once(many years ago) used Naclo3 to form red pd---it was not allowed naclo3 here in Brazil---so i used 2methods---the first,to the nitric or ar containing pd solution,i added nh4cl ,then clorox--the second method was with dmg----------and a third totally different method:to the ar or nitric solution i added nh4cl powder(dissolved in the ar solution ) and then nh4oh ---filtrated and to the filtrate i added hcl to form yellow salt--then,formic acid or hidrazine to reduce the yellow salt to black pd powder
thanks and regards, 
Arthur


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## johnny309 (Sep 1, 2013)

Mrs. Arthur...instead of NaOCl3......you can use any source of chlorine ....sodiumhypoclorate (has the formula NaOCl)....it is the bleach that it is used in every home.


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## arthur kierski (Sep 1, 2013)

johnny309 said:


> Mrs. Arthur...instead of NaOCl3......you can use any source of chlorine ....sodiumhypoclorate (has the formula NaOCl)....it is the bleach that it is used in every home.


 i think that you wanted to say instead of naclo3(not(naocl3),you could use naocl(sodium hypoclorite)---you are right and that is what i do---------
regards
Mr. Arthur(not Mrs.)


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## Harold_V (Sep 2, 2013)

More or less adding credence to the notion that ammonium chloride, in and of itself, does not precipitate palladium as the familiar red powder (although it is very much an essential part of the process). Were that the case, when precipitating platinum, palladium would come down at the same time. 

Thanks, Arthur. 

Harold


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## freechemist (Sep 2, 2013)

Indeed, the chemistry of direct precipitation of palladium dissolved in nitric acid alone, using solely ammonium chloride is complex. It is less complicated in precipitation from solutions in aqua regia, and/or prepared by dissolution of Pd in the system HCl/Cl2, where a lot of excessive chloride is already present. Whenever working with ammonium chloride, one fact has to be taken into consideration: the inhering danger of sudden, uncontrolled reaction of a possibly strong reducing agent (e.g. the ammonium ion) with a possibly strong oxidant (e.g. chlorate, hypochlorite, elemental chlorine especially), like Arthur Kierski describes it in his post. This danger can be overcome easily, by using potassium chloride, KCl, in place of ammonium chloride, precipitating the salt K2PdCl6, instead of (NH4)2PdCl6. In my practice, recovering and refining Pd and Pt from Pd/Pt-scrap, dental alloy-scrap and the like, I never encountered any disadvantage on using KCl in place of NH4Cl.

Regardless of the composition of a Pd-solution, the Pd to be precipitated has to be in the (+IV)-oxidation- state, and enough free HCl has to be present. Dissolution of Pd-metal in solely HNO3, aqua regia, and/or HCl/Cl2 usually leads to dissolved Pd in the (+II)-oxidation state. Further oxidation to Pd(IV) can be accomplished with bleach, Cl2, NaClO3, and, in some cases, even with HNO3, if solutions are heated, and if it's concentration is high enough, like in AR or in solutions obtained by reaction of metallic Pd in 1:1 conc.HNO3/H2O, providing, enough chloride; in form of HCl, KCl, NH4Cl; is added, to transform all dissolved Pd into the PdCl62--anion completely, and enough additional acid is present, to facilitate the needed redox-reactions. This, may be, explains the sometimes erroneous results obtained by just adding saturated NH4Cl-solution to Pd, dissolved in 1:1 conc.HNO3/H2O.


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## solar_plasma (Sep 2, 2013)

solar


> Would't nitric form AR with NH4CL with lots of free native Cl's? And where will NH4+ go? Won't it be possible, that reactions are taking place similar to when NH4OH and Chlorox is used (don't know the sequence to not to blow the vessel).



freechemist


> and, in some cases, even with HNO3, if solutions are heated, and if it's concentration is high enough, like in AR or in solutions obtained by reaction of metallic Pd in 1:1 conc.HNO3/H2O, providing, enough chloride; in form of HCl, KCl, NH4Cl; is added, to transform all dissolved Pd into the PdCl62--anion completely, and enough additional acid is present, to facilitate the needed redox-reactions. This, may be, explains the sometimes erroneous results obtained by just adding saturated NH4Cl-solution to Pd, dissolved in 1:1 conc.HNO3/H2O.



Thank you freechemist! Perfect answer to my question.


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## JHS (Sep 2, 2013)

(This effect is one of the considerations mentioned above, which is
not easily explained to the non-chemist and about which we shall
say something in the "Questions and Answers" at the end of this
chapter.) After that, the solution is placed in an evaporating dish
and concentrated somewhat, until there is no longer an odor of
chlorine.
If ammonium chloride should be added at this point, it will precipitate
platinum as the orange powder, and most of the palladium
and iridium will come down with it. (The color of the powder
will run from pale yellow to deep maroon, depending upon the
proportions of the various metals and the temperature of the reacting
substances.)

In some cases this is a satisfactory method that is, some workers
are willing to obtain all their platinum-group metals together in
this way, and then repurify the powder as required
hoke pg.157
didin't add chlorine,so saw no need to evaporate
didin't state that platinum groups would not drop.
didin't have any other platinum group metals in solution
material was 90%pd
desolved in 1 to 1 50/50 nitric h20


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## lazersteve (Sep 2, 2013)

There is written scientific evidence to the fact that NH4Cl *alone* will precipitate Pd from nitrate bearing solutions here:



Standard Methods of Chemical Analysis said:


> Ammonium chloride precipitates palladium as (NH4)2PdCl4 from the nitrate.



and the quoted book:

Pd From Nitrates with NH4Cl

I have personally tested this process with Nitric Acid and Pd (no Pt, no AR or chlorine) and it works. 

Think about it: If ammonium chloride alone will *not* precipitate Pd from nitrate solutions, then why must we denoxx to separate the Pt from the Pd with AR? The answer is simply because, NH4Cl will precipitate both Pd and Pt from nitrate bearing solutions. We denoxx solutions of PGMs to allow better separation of the Pt and Pd.

Steve


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## arthur kierski (Sep 2, 2013)

As butcher said in his trhread(hokes other methods+)--if the metals are mixed ,pd,pt and au(from ar) ,will come as a marron pwder with nh4cl precipitation

Jhs,said that his material was 90% pd ---

when i tried a few years ago,with catalysers---the nh4cl precipitation
dropped as a marron powder,pt and pd(and perhaps rh)-----i did not continue this method because as mentioned by Butcher,when the remaining liquid was tested wth sncl2 it gave positive for pgm
Arthur


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## JHS (Sep 2, 2013)

Arthur,
perhaps,maby you got a posative because you filtered your solution before the rh dropped.
it is my understanding that it takes 24 hours for rh to drop.
after dropping the pt.pd.and filtering, you must leave the solution undisturbed for 24 hours for rh to drop.
this theory is from study not practical experience,so i have no defence for it.


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## Harold_V (Sep 3, 2013)

lazersteve said:


> Think about it: If ammonium chloride alone will *not* precipitate Pd from nitrate solutions, then why must we denoxx to separate the Pt from the Pd with AR? The answer is simply because, NH4Cl will precipitate both Pd and Pt from nitrate bearing solutions. We denoxx solutions of PGMs to allow better separation of the Pt and Pd.


Thanks, Steve.. That was the missing link for me, and easily overlooked considering I have not refined or looked at Hoke's book for almost 20 years. I clearly do not recall that information.

Harold


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## butcher (Sep 3, 2013)

Sounds like somebody needs to re-read Hoke's :lol: 
Ole dogs can learn new tricks.

This is a very interesting thread, it is amazing what we can all learn, and possible learn a few new tricks, or get a better understanding of the details of what may be going on in these chemical reactions by sharing ideas or what we have learned with each other, and this also helps to demonstrate how minor details in a process can make major effects on the outcome or reaction of that chemical process.


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## Harold_V (Sep 4, 2013)

butcher said:


> Sounds like somebody needs to re-read Hoke's :lol:


Heh! I have much better things to do with my time. I'll just leave such matters to others, as I clearly am not properly informed. I'd feel differently if I had intentions of future refining, but, alas, I do not.

Harold


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## niteliteone (Sep 4, 2013)

Harold_V said:


> butcher said:
> 
> 
> > Sounds like somebody needs to re-read Hoke's :lol:
> ...


*LOL* :shock:
Now your sounding like a newbie :lol:


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## Harold_V (Sep 4, 2013)

Chuckle!

Yeah, but with one huge difference. My days of refining are over. I have no plans to do anything related to refining--and I'm spread thin--the very reason why I have spent less of my time here in the immediate past. For me to waste what little time I have by studying a subject that will not serve my needs makes no sense---as there are others here who have far greater knowledge and can readily pick up the places where I, or others, are deficient. Further, I have no interest. None. I am here for one reason, and one reason only. To share what little I know with those who know even less. That has been done, as I've posted pretty much everything I know at this point. 

You can believe me when I tell you that, unlike a newbie, who asks questions instead of reading, I won't be asking any questions, wasting the time of those with knowledge. And, when my lack of knowledge appears to be a hindrance, so the board is not served by my presence here, I will be gone. I prefer that to wasting what little time I have left in this mortal life, reading on a topic that no longer is of interest to me. 

Harold


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## arthur kierski (Sep 4, 2013)

Harold,your experience is more important then any knowledge --i sincerelly hope that you keep on with your work in the forum---you with your threads ,helped me to overcome many mistakes that i made during this wonderfull journey in the gold refining forum

thanks for everything, from your admirer
Arthur Kierski


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## solar_plasma (Sep 4, 2013)

Dear Harold,
you have left something immortal on this board, your knowlegde, your experience, but even more valuable and unique: a personal attitude about refining. I said it before and I say it again, an attitude that not only benefits in refining but in many challenges of life. An attitude about not doing things only halfways. An attitude I find again in Zen and Taoism. In this quick society we tend to do things fast, instead of doing them well. We tend to know a little about everything, instead of staying at one thing until we really have understood.

I hope, you stay on the board, you can still do difference.


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## JHS (Sep 4, 2013)

Harold,
If I stop learning, I become useless to those I teach.No one can know all there is to know.
If they did what would be the use in continuing there existence.
you started roaming this earth with the t rex,i started two years after you.
I would not presume to even think i know everything.
your process works.if it were not for your insistance,no one would have gained the knowledge of this thread.
so as one old goat to another,share,be correct, be incorrect,but share.
In the end all that matters is that we try.
john
P.S.DON'T make me feel bad for asking.I'm too old and do not want to feel bad.
john


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## butcher (Sep 4, 2013)

Harold, 
You still have a lot to say, and teach, you show us from your vast experience, you still teach us many new things of recovery and refining from the skills you have gained over the years, but one important thing you do here cannot be replaced by books, or reading, or study, and I do not see any that can fill your shoes, it has little to do with refining, but helps all of us to improve ourselves, and helps to keep this forum what you and others have made it with your hard work, wisdom, and with the no nonsense attitude, which helps us not only to strive for perfection in our refining of these metals, but also in other areas of life, the forum needs, and greatly appreciates your presence here, and still needs it.

Thanks

P.S. Hope you have lots of time to re-read Hokes book, although you can probably write a book just as good or better, and could probably quote most everything in her book in your own words, Hoke's book is still a great book to read before falling of to sleep at night.
But more importantly I hope you can always find time for the forum and all of your friends here.


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## maynman1751 (Sep 4, 2013)

butcher said:


> Harold,
> You still have a lot to say, and teach, you show us from your vast experience, you still teach us many new things of recovery and refining from the skills you have gained over the years, but one important thing you do here cannot be replaced by books, or reading, or study, and I do not see any that can fill your shoes, it has little to do with refining, but helps all of us to improve ourselves, and helps to keep this forum what you and others have made it with your hard work, wisdom, and with the no nonsense attitude, which helps us not only to strive for perfection in our refining of these metals, but also in other areas of life, the forum needs, and greatly appreciates your presence here, and still needs it.
> 
> Thanks
> ...



+1 I don't think that it can be said any better. Butcher, you also are a gift to this forum and its members. Your patience, understanding and explanations are invaluable. You both had better stay with us! 8)


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## Lou (Sep 18, 2013)

So my questions are:

What's the source material?
What's the Pd concentration in the solution?
What's the oxidation-reduction potential?


Pd will precipitate with ammonium chloride, but as freechemist observed, it is not a simple chemical system.

Nitric, if hot and concentrated, will oxidize the ammonium cation to NOx. The chloride forms an in-situ aqua regia.

The precipitation from aqua regia solutions is rarely complete in the presence of nitrate, and far from complete in simple nitric acid.


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