Can help me for reduce PD dmg...

[fabriciomnarvaez]

Hey guys... I have a fair amount of PD DMG, I've already cleaned it with warm water, what would be the best way to reduce this stuff? Here in Brazil, they use a mufla furnace, but I don't have that furnace, or is there a less complicated way to reduce it?

 

[andu]

Probably easiest way is finding a oxy torch close by, even a gas furnace could do it but tools might melt on those temps and could perhaps get dangerous. No idea what temp you need for that but i'm assuming around 1560ºc.

 

[fabriciomnarvaez]

Probably easiest way is finding a oxy torch close by, even a gas furnace could do it but tools might melt on those temps and could perhaps get dangerous. No idea what temp you need for that but i'm assuming around 1560ºc.

in a conventional furnace, how many degrees?

 

[andu]

A normal gas furnace like devil forge for example should get up to 1600ºc, the problem is that your tools will probably melt against the crucible, the graphite will start to corrode fast (even faster if you use borax).

What I would do, IF it does melt thing that is doubtful is leave it to cool in the crucible till it can be pulled out.
This isn't the exact temperature but I know bigstackd had his iron molds melting more than once when preheating inside the furnace and you are about 100º away.

And again, trying to run it at such temperature might be extremely dangerous. I would search for a oxy-acetylene torch close by, thing that should be fairly easy to find and goes even for platinum,

edit: actually, seems i were wrong, palladium and iron melting points are very close one to another, and the furnace CAN melt iron so it should be able to get to palladium too ( I have no idea if the sponge you have has same melting point as palladium metal, and the furnace itself isn't designed for iron, it should work but don't get used to it and search for a oxy torch). Main problem, again, is probably pulling it out without your tools melting.

Edit two: Got myself into researching a bit and seems the oxy torch is Oxy-hydrogen or oxy-propane, not acetylene, no idea if that one would work.

 

[Lino1406]

Hey guys... I have a fair amount of PD DMG, I've already cleaned it with warm water, what would be the best way to reduce this stuff? Here in Brazil, they use a mufla furnace, but I don't have that furnace, or is there a less complicated way to reduce it?

Melting Pd-DMG is nasty thing. Better to convert it to palladium ammonium chloride with 1. NH4OH
2. HCl or to go directly there. The details can be found in the forum

 

[Yggdrasil]

in a conventional furnace, how many degrees?

Careful, the temperature need to be carefully controlled, if the smoke goes grey you are loosing Pd.
You can do HCl Zinc or Formate reduction.
For Formate reduction read Hokes.

 

[Yggdrasil]

in a conventional furnace, how many degrees?

There was a lot of answers here with slightly different angles of approach.
You have a Pd DMG salt and you want to “reduce” it.
To clarify, you want it to be converted to metal, right?
Often we use a technique called calcining for some metal salts, it is used for Pd Ammonium Chloride among others.
I do not know if DMG is suited for this procedure hence Lino’s proposal to convert it to Pd Ammonium Chloride.

It can however be reduced by Formate reduction or reduced/cemented by HCl and Zinc.

Edit to add:
Formate reduction is explained both here on the forum and in Hokes book
HCl Zinc method has been used on the forum too, from the top of my head by at least a member called kjavanb.

Edited for spelling

 

[lazersteve]

Hey guys... I have a fair amount of PD DMG, I've already cleaned it with warm water, what would be the best way to reduce this stuff? Here in Brazil, they use a mufla furnace, but I don't have that furnace, or is there a less complicated way to reduce it?

I have processed many, many ounces of Pd-DMG complex and the easiest method by far is to calcine it.

1)After through washing place your slightly moist yellow complex and filter paper in a large porcelain, fused quartz, or stainless steel container that is large enough to allow it to be spread out into a layer a few centimeters thick.
2) Gently heat the container from above with a propane canister torch to until all the moisture is driven off. Go low and slow here.
3) The complex will darken to a char like appearance around the edges and finally ignite producing its own flame. Stop heating and allow the mass to burn.

4) Oxygen flow and an occasional heating from above are required to initiate this process to the point where it proceeds on its own.

5) After the complex fully burns down to a crunchy stiff mass begin Gently heating from above until it changes from the char color to a ash grey sponge with peacock highlights.
6) Break up the Pd and heat with the torch to be sure all the interior is throughly converted.
7) Reprocess the resulting peacock colored gray material using your favorite Pd purification process which does not involve DMG from this step forward.

Here's a link to one of my post with photos:

https://goldrefiningforum.com/threads/im-having-trouble-cementing-palladium-help.32593/post-347037And
https://goldrefiningforum.com/threads/im-having-trouble-cementing-palladium-help.32593/post-347057Steve

 

[kurtak]

Probably easiest way is finding a oxy torch close by, even a gas furnace could do it but tools might melt on those temps and could perhaps get dangerous. No idea what temp you need for that but i'm assuming around 1560ºc.

Per the bold print - You clearly don't know what you are talking about --- if you put the yellow Pd/DMG salt directly in a furnace at those temps (1560c) &/or try to melt it directly with an oxy (plus gas) torch MUCH of your Pd WILL go up in smoke

In other words a good amount of you Pd is going to be volatized & lost into the air if you try to directly melt the yellow salt at those temps

The yellow salt MUST first be reduced to actual Pd metal to prevent the Pd from being volatized & going up in smoke --- once the yellow salt is reduced - then you can melt the reduced Pd metal

Three options for FIRST reducing the yellow salt to actual Pd metal before then going to melting the (the once reduced) Pd metal

1) calcination of the yellow salt - this is done as a low temp reducing roast of the salt at "about" 600F (or 315C)

It is the same principle as roasting sulfide ores to reduce gold sulfides to actual gold metal

2) Chemical reduction using formic acid as your reduction agent

3) ion exchange using a more reactive metal (such as zinc) to make the ion exchange that reduces the less reactive metal salt (Pd/DMG) to its actual metal (Pd)

Simply take your Pd/DMG salt - make a slurry by adding HCl - then add zinc metal (zinc powder or shavings) & stir until the yellow salt is reduced to a black Pd sponge - put the sponge through HCl washes to remove any excess zinc left after the reduction process

Kurt

 

[fabriciomnarvaez]

I have processed many, many ounces of Pd-DMG complex and the easiest method by far is to calcine it.

1)After through washing place your slightly moist yellow complex and filter paper in a large porcelain, fused quartz, or stainless steel container that is large enough to allow it to be spread out into a layer a few centimeters thick.
2) Gently heat the container from above with a propane canister torch to until all the moisture is driven off. Go low and slow here.
3) The complex will darken to a char like appearance around the edges and finally ignite producing its own flame. Stop heating and allow the mass to burn.
4) Oxygen flow and an occasional heating from above are required to initiate this process to the point where it proceeds on its own.
5) After the complex fully burns down to a crunchy stiff mass begin Gently heating from above until it changes from the char color to a ash grey sponge with peacock highlights.
6) Break up the Pd and heat with the torch to be sure all the interior is throughly converted.
7) Reprocess the resulting peacock colored gray material using your favorite Pd purification process which does not involve DMG from this step forward.

Here's a link to one of my post with photos:

https://goldrefiningforum.com/threads/im-having-trouble-cementing-palladium-help.32593/post-347037And
https://goldrefiningforum.com/threads/im-having-trouble-cementing-palladium-help.32593/post-347057Steve

If you have experience with Pd-dmg, let me ask you something here, so you don't have to open a new topic, after I precipitate the PD with the dmg, and filter the solution, this solution will turn indigo blue, how to know if all the PD has been precipitate? I'm processing large quantities...

 

[lazersteve]

If you have experience with Pd-dmg, let me ask you something here, so you don't have to open a new topic, after I precipitate the PD with the dmg, and filter the solution, this solution will turn indigo blue, how to know if all the PD has been precipitate? I'm processing large quantities...

The two normally accepted tests for Pd in solution are stannous and DMG in acid medium.

Steve

 

[Yggdrasil]

If you have experience with Pd-dmg, let me ask you something here, so you don't have to open a new topic, after I precipitate the PD with the dmg, and filter the solution, this solution will turn indigo blue, how to know if all the PD has been precipitate? I'm processing large quantities...

Any liquids we process, will have to be tested with a Stannous test.
Stannous is our eyes in refining.

Edit to add:
Steve beat me to it.

 

[rusti2]

I think it is convenient to mention that the gases produced by the calcination of dimethylglyoxime produce some highly toxic HCN (hydrocyanic acid). Take precautions to do so under an extraction hood or in ventilated areas.

 

[andu]

Per the bold print - You clearly don't know what you are talking about --- if you put the yellow Pd/DMG salt directly in a furnace at those temps (1560c) &/or try to melt it directly with an oxy (plus gas) torch MUCH of your Pd WILL go up in smoke

In other words a good amount of you Pd is going to be volatized & lost into the air if you try to directly melt the yellow salt at those temps

The yellow salt MUST first be reduced to actual Pd metal to prevent the Pd from being volatized & going up in smoke --- once the yellow salt is reduced - then you can melt the reduced Pd metal

Three options for FIRST reducing the yellow salt to actual Pd metal before then going to melting the (the once reduced) Pd metal

1) calcination of the yellow salt - this is done as a low temp reducing roast of the salt at "about" 600F (or 315C)

It is the same principle as roasting sulfide ores to reduce gold sulfides to actual gold metal

2) Chemical reduction using formic acid as your reduction agent

3) ion exchange using a more reactive metal (such as zinc) to make the ion exchange that reduces the less reactive metal salt (Pd/DMG) to its actual metal (Pd)

Simply take your Pd/DMG salt - make a slurry by adding HCl - then add zinc metal (zinc powder or shavings) & stir until the yellow salt is reduced to a black Pd sponge - put the sponge through HCl washes to remove any excess zinc left after the reduction process

Kurt

I'm pretty sure I mentioned atleast once I have no idea of the requiered temperature and that i simply taken palladium melting point as needed reference.

 

[Yggdrasil]

I think it is convenient to mention that the gases produced by the calcination of dimethylglyoxime produce some highly toxic HCN (hydrocyanic acid). Take precautions to do so under an extraction hood or in ventilated areas.

I just had a glance at the formula and to me at least, that seem unlikely.
So can you please elaborate?

 

[rusti2]

https://www.mdpi.com/2073-4344/10/3/331

 

[Yggdrasil]

https://www.mdpi.com/2073-4344/10/3/331

Thanks.
So it is obvious again that we deal with some nasty compounds.
Be safe folks and take precautions, always.

 

[rusti2]

Thanks.
So it is obvious again that we deal with some nasty compounds.
Be safe folks and take precautions, always.

If the calcination conditions are strongly oxidizing, the formation of hydrocyanic acid would be avoided, but it is good to take precautions

 

[Yggdrasil]

If the calcination conditions are strongly oxidizing, the formation of hydrocyanic acid would be avoided, but it is good to take precautions

True.
But one tries to calcine at the lowest possible temperature to avoid metal loss.
Usually around 300+-

 

[rusti2]

True.
But one tries to calcine at the lowest possible temperature to avoid metal loss.
Usually around 300+-

That's right, it is convenient to start low with progressive increases ending in oxidizing conditions, the exothermic peak of the decomposition of dimethylglyoxime is around 300°C, according to the research work.