Palladium in a soil sample

[sayf]

I got soil that contains palladium , it was already a powder so i directly added some nitric acid to the soil and heated for 2 hours on a low fire , any ways i filtered the nitric and did a stannous test and the cotton turned into deep dark black in no time , so does this ensure that the soil contains palladium ?
also can i use diluted nitric acid to dissolve the palladium in the soil or i need the nitric to be concentrated ?

I looked alot to find a clear answer for my following question but no luck so far .

i have chlorine gas, ammonium chloride, SMB , iron sulfate as reducing agents but cant afford DMG ... can i use any of those to make a sellective palladium precipitation from the nitric solution directly given that the soil may contain nickel and silver , if not can i use any of them to make a sellective palladium precipitation from the aqua regia after eleminating the nitric acid ?
Regards
sayf

 

[jimdoc]

Where is this soil from? Why did you suspect it to contain palladium? You should post some pictures.

 

[sayf]

Where is this soil from? Why did you suspect it to contain palladium? You should post some pictures.

its taken from a smashed rock , i was told from a geologist that it contains palladium
the stannous chloride test for the nitric gave me 70 % hope that he is right
The first pic is the rock
The second for the rock turned into powder

 

[Whatthephunk]

Did your geologist friend get it assayed to determine that it had PGMs? If he did then see if you can get a copy of the report. It'll tell you what elements are in there and the amounts. Without having the rock sample in hand it would be hard to tell if there is any oxide or minerals present that indicate a large amounts of any element. If there is PGM present, then I'd also check for gold, silver and any base metals you'd be interested in.

To make it easier, so you're not wasting reagents, I'd melt it with lead as a collector metal and then cuppell it. That would leave you with a button of precious metals.

I wouldn't expect a lot of precious metals from a sample that size though. Really high grade ore is tens of grams per ton.

FYI, the term soil is usually reserved to the top layer of sediment that has a large amount of organic matter in it.

 

[Lino1406]

Stannous chloride should 1stly give the red PdCl2 color before turning to black. Immediate black can mean tellur or arsenic which sometimes are accompanied by PM's. The source is Jordan?

 

[sayf]

Did your geologist friend get it assayed to determine that it had PGMs? If he did then see if you can get a copy of the report. It'll tell you what elements are in there and the amounts. Without having the rock sample in hand it would be hard to tell if there is any oxide or minerals present that indicate a large amounts of any element. If there is PGM present, then I'd also check for gold, silver and any base metals you'd be interested in.

To make it easier, so you're not wasting reagents, I'd melt it with lead as a collector metal and then cuppell it. That would leave you with a button of precious metals.

I wouldn't expect a lot of precious metals from a sample that size though. Really high grade ore is tens of grams per ton.

FYI, the term soil is usually reserved to the top layer of sediment that has a large amount of organic matter in it.

its about 2 kilograms sample , these rocks have huge density
Never seen anything like that before , any ways i already have nitric with the metals dissolved inside it , is there a direct way to precipitate palladium from nitric directly
Or i need to change the nitric into AR then eleminate the nitric and precipitate using chlorine gas ?

 

[sayf]

Stannous chloride should 1stly give the red PdCl2 color before turning to black. Immediate black can mean tellur or arsenic which sometimes are accompanied by PM's. The source is Jordan?

i made the stannous test in nitrate solution so the color will vanish very quickly i think you mean the test in chloride solution right ?

 

[Lino1406]

I mean SnCl2 with Pd++ will initially give red PdCl2 which is moderately soluble, then turning to black

 

[kurtak]

Did your geologist friend get it assayed to determine that it had PGMs?

You never answered that question - its important - without an actual assay you are working blind which in turn can be "very" dangerous when you start trying to dissolve metals in rocks/ore with acids --- why ?

because they are "likely" to contain "toxic" elements like arsenic (as just one example)

I mention arsenic because that is what the rock you posted a pic of looks like to me

Here is a pic of a piece of ore that is very high in arsenic (like 70 plus percent)

Iridium & Gold Processing For Beginners

If your geologist friend tested the rock with an XRF DO NOT trust those results - XRF are (well) known for giving "false" readings for PGMs - when in fact what the XRF "claims" to be PGMs is actually arsenic (or other elements the XRF does not recognize)

As far as a stannous test for Pd - the test will "first" appear as a red/orange color - but that color is very momentary & quickly turns to a deep dark green (think forest green) if the Pd is concentrated enough it 'may" appear black but will actually have a green tint to the black --- kind of like a stannous test for gold which is purple - but if concentrated enough will look black but will actually be a purple/black

If the Pd (or gold) is so concentrated that the test shows black (when done in a spot plate/plastic spoon - then try doing your stannous test on a piece of filter paper or paper towel (put a drop of stannous on the paper - then a drop of the solution on the drop of stannous) the black will appear (mostly) in the center of the test - but the purple (for gold) or the green (for Pd) will appear out at the edges of the test

One other test you can do (being this is a nitric solution) is put a piece of copper (wire) in the solution - if silver is dissolved it will cement out & (depending on how concentrated) will fall off the copper or hang to the copper with a loose grainy texture - if Pd is in solution it will cement "onto" the copper with a "tight" bond to the wire (like it is "plated" to the copper)

Bottom line - you should not be treating ore samples with acids until you have FIRST had an "actual assay" done on them first --- other wise you are taking a (big) risk of creating some very toxic waste

The pic of the rock looks high in arsenic to me - but I could be wrong about that

You NEED to have an "actual" assay done on it - & the assay needs to be done for PGMs - other wise you are working blind & may well be doing nothing other then making very toxic waste

Kurt

 

[sayf]

Did your geologist friend get it assayed to determine that it had PGMs?

You never answered that question - its important - without an actual assay you are working blind which in turn can be "very" dangerous when you start trying to dissolve metals in rocks/ore with acids --- why ?

because they are "likely" to contain "toxic" elements like arsenic (as just one example)

I mention arsenic because that is what the rock you posted a pic of looks like to me

Here is a pic of a piece of ore that is very high in arsenic (like 70 plus percent)

https://goldrefiningforum.com/phpBB3/viewtopic.php?f=49&t=27934&p=297984&hilit=arsenic#p297984
If your geologist friend tested the rock with an XRF DO NOT trust those results - XRF are (well) known for giving "false" readings for PGMs - when in fact what the XRF "claims" to be PGMs is actually arsenic (or other elements the XRF does not recognize)

As far as a stannous test for Pd - the test will "first" appear as a red/orange color - but that color is very momentary & quickly turns to a deep dark green (think forest green) if the Pd is concentrated enough it 'may" appear black but will actually have a green tint to the black --- kind of like a stannous test for gold which is purple - but if concentrated enough will look black but will actually be a purple/black

If the Pd (or gold) is so concentrated that the test shows black (when done in a spot plate/plastic spoon - then try doing your stannous test on a piece of filter paper or paper towel (put a drop of stannous on the paper - then a drop of the solution on the drop of stannous) the black will appear (mostly) in the center of the test - but the purple (for gold) or the green (for Pd) will appear out at the edges of the test

One other test you can do (being this is a nitric solution) is put a piece of copper (wire) in the solution - if silver is dissolved it will cement out & (depending on how concentrated) will fall off the copper or hang to the copper with a loose grainy texture - if Pd is in solution it will cement "onto" the copper with a "tight" bond to the wire (like it is "plated" to the copper)

Bottom line - you should not be treating ore samples with acids until you have FIRST had an "actual assay" done on them first --- other wise you are taking a (big) risk of creating some very toxic waste

The pic of the rock looks high in arsenic to me - but I could be wrong about that

You NEED to have an "actual" assay done on it - & the assay needs to be done for PGMs - other wise you are working blind & may well be doing nothing other then making very toxic waste

Kurt

Thanks for your reply kurt but my friend is an expert and has some kind of device that detect the precious metals and gave me the orecious metals content in the sample
it shows that the sample contains 0.01 gram palladium / kilo And 0.2 gram silver/kilo and about 0.04 gram gold/kilo , no arsenic is there no worries .
i was just wondering if there are any ways other than chlorine gas to precipitate the palladium from the nitric directly , if the copper will cement both silver and palladium together then separating them will lead me to aqua regia and this will not solve my problem it will just add more steps for me
can the zinc precipitate from nitric directly ?
also can i use diluted nitric for the purpose of disolving palladium from soil or it has to be concentrated ?

 

[Whatthephunk]

Are you sure it wasn't ppm/ppb or percent? Those numbers are upwards of 20g/ton and I'd expect to see some sort of mineralization of the rock at the those values. Any chance you could ask what process he used to test it?

My chemistry experience is very limited, so I'm afraid I can't help you on that front, just trying to make sure you're not creating something dangerous.

 

[kurtak]

Thanks for your reply kurt but my friend is an expert and has some kind of device that detect the precious metals and gave me the orecious metals content in the sample

If the "device" your friend used was an XRF (which is likely) I would not count on the results being true

Not all XRFs are created equal --- they (XRFs) depend on the elements that are programed into them

If a certain element is NOT programed in the XRF - the XRF will see that element - BUT - because the element is not in the XRF program it will call that element something that is in the XRF program

To better explain here are two examples of what I am talking about

(1) when I first started refining I took one of my first pieces of gold into a scrap yard that had an XRF to have them test it as I wanted to see how good I did with my first refine of gold - when they tested my gold with the XRF the XRF said it was a piece of tungsten --- that is because gold was not programed into their XRF but tungsten was - so the XRF saw the gold - but because gold was not in the program - it "called" it tungsten

When I went to England for a get together of 6 of our members - Goran was one of those members - Jon had an XRF - Goran brought a piece of arsenic ore with him - we tested the arsenic ore with the XRF - the XRF saw the arsenic but called the arsenic iridium

Here is a link to that XRF test of the arsenic ore

:arrow: False Iridium finds

Then there are some elements (like beryllium) that an XRF wont read at all - so the XRF will refer to them as "light elements"

In other words - an XRF is only as good as the programing in the XRF - AND - they are not really made to read (test) rocks --- they are made to test real metals

Mining companies (&/or geologist) do use XRFs on rocks - but not for a 'true" test of what is in the rock but rather as away to get an indication of what MAY be in the rock & thereby how to proceed with a true assay of the rock (ore)

In other words you can not depend on the XRF reading of a rock - you still NEED to have a real assay done - to confirm what the XRF says --- other wise you can end up casing you tail looking for something that may (or NOT) be there because as much as an XRF may indicate something in a rock --- it can also give false reads of what it THINKS is in the rock

Maybe Goran can chime in here & explain it better then I can

Kurt

 

[kurtak]

Are you sure it wasn't ppm/ppb or percent?

If an XRF was used the reading of the XRF will be in percent AND that percent reading will be for what the XRF reads on "the surface" at the point the XRF took the reading (test) which is only about a square inch (or less) of surface area

Therefore the reading will not even come close to what is actually in the the rock - at best it can only give you an "indication" of what MIGHT be in the rock

And as I pointed out in my other post XRFs are well known for giving false readings of what is in a rock when an XRF is used to test a rock

At best - An XRF may (or not) tell you that a rock is worth (or not) having an actual assay done on it

Until an actual assay is done - all you really have is a "guess" of what you THINK might be in the rock

Kurt

 

[kurtak]

One thing that is For Sure --- I would NEVER buy a box of rocks (&/or ground up ore) based on a test/read out of an XRF

Kurt

 

[g_axelsson]

Maybe Goran can chime in here & explain it better then I can

Kurt

I was thinking that you did a very good work all through, couldn't have said it better myself.

Göran

 

[sayf]

hello great friends
i posted lastly that i got a rock sample that contain palladium within , i smashed it into a powder , heated the powder well to get rid of any sulfur , washed the powder many times then added diluted nitric acid to the powder , , stirred well while giving low heat for about 2 hours then i filtered the reddish nitric and tested it by stannous chloride , the color has firstly changed into deep green then turned into deep black then vanished after few seconds and the sample came back to its original color
then i followed kurt's advice to cement PGMs with copper powder , i added copper powder to the nitric , a slow reaction started but all copper has dissolved as the solution color started to change and alittle precipitate appeared at the bottom , i dont know if that is palladium but i made sure that the sample doesnt contain any silver ,
my question is : will not the nitrate solution redissolve precipitated palladium ???
when i used iron sulfate to test the nitrate solution i got a perminant deep black color , what does that indicate???
am a bit confused isnt the iron sulfate an exclusive tester for the presence of gold only ?

regards

 

[FrugalRefiner]

sayf, please keep related posts in the same thread. I've moved this post here since it's on the same subject. Creating new threads on a similar subject makes it more difficult for people to help you.

Dave

 

[sayf]

sayf, please keep related posts in the same thread. I've moved this post here since it's on the same subject. Creating new threads on a similar subject makes it more difficult for people to help you.

Dave

thanks dave , i appreciate your help

 

[sayf]

as an update , the copper powder has disappeared and this precipitate appeared , is it the palladium ? its color is reddish as u can see in the picture

 

[kurtak]

Sorry for the delay in replying to this (& the PM you sent me about this)

But NO that does not look like Palladium to me - Pd that has been cemented from solution with copper (&/or with zinc) should be a "dark" gray to black

It should look like the precipitate in the filter in this picture

:arrow: Fuzz Button Interconnects, need some advice

Based on the precipitate in your pic - my guess would be one of two things

(1) if it was a nitric solution - as much as it may have appeared that all the copper powder dissolved - some of it may not have actually dissolved (because all the "free" acid was used up) & so the (little bit) of remaining copper powder settled

(2) if it was an AR solution (chloride plus oxidizer) then it could be the same as above (copper) or gold (if gold was dissolved) or a combination of gold/copper

test I would do --- decant the solution (remove the solution) keeping the powder in the beaker - add some nitric (if the nitric is 67 - 70 % dilute 50/50 with distilled water) - if the powder dissolves test it with stannous --- if the powder does not dissolve add some HCl which should then dissolve it - test that with stannous

Kurt