Palladium sponge mystery

[kjavanb123]

I am so puzzled of what happened. Percipitated then dried 84g of palladium sponge, went to same platinum jewler with hydrogen torch who happened to melt all my palladium sponge in the past succesesfully, witnessed the whole melting process and resulting button was just puzzled me, only 6g of impure palladium, wth??

To percipitate that amount of palladium sponge, I used zinc percipitation and some of the solution I used DMG percipitation and in all of those I used 10% hcl plus zinc powder to convert the yellow salt to palladium sponge, I even dissolved a gram of it in nitric acid and got strong Pd peresnece upon using stannous chloridd test.

A sample of the same palladium black powder weighing 0.3g was added on top of 2g rolled palladium metal, and melted in a vaccummed induction furnace and it produced 2.5g button that was contaminated with carbon as the crucible in the induction furnace was graphite. But it still looked like a brittle palladium.

I read and tested at least 5 times that whatever the amount of palladium sponge was once melted it should produce very similar amount of palladium metal. But over 76g of loss I mean what could those powders be? Did they evaporate? Most of it turned to dark greenish slags on the melting cruicble.

I am confused, could it be the DMG or zinc that I used were contaminated??

 

[Anonymous]

What quantity of base material did you get this from and what kind of material was it Kevin?

 

[sierrabravo2022]

I am so puzzled of what happened. Percipitated then dried 84g of palladium sponge, went to same platinum jewler with hydrogen torch who happened to melt all my palladium sponge in the past succesesfully, witnessed the whole melting process and resulting button was just puzzled me, only 6g of impure palladium, wth??

To percipitate that amount of palladium sponge, I used zinc percipitation and some of the solution I used DMG percipitation and in all of those I used 10% hcl plus zinc powder to convert the yellow salt to palladium sponge, I even dissolved a gram of it in nitric acid and got strong Pd peresnece upon using stannous chloridd test.

A sample of the same palladium black powder weighing 0.3g was added on top of 2g rolled palladium metal, and melted in a vaccummed induction furnace and it produced 2.5g button that was contaminated with carbon as the crucible in the induction furnace was graphite. But it still looked like a brittle palladium.

I read and tested at least 5 times that whatever the amount of palladium sponge was once melted it should produce very similar amount of palladium metal. But over 76g of loss I mean what could those powders be? Did they evaporate? Most of it turned to dark greenish slags on the melting cruicble.

I am confused, could it be the DMG or zinc that I used were contaminated??

what is the difference between palladium sponge and palladium powder. I'm a newby. Thanks

 

[Alondro]

I am so puzzled of what happened. Percipitated then dried 84g of palladium sponge, went to same platinum jewler with hydrogen torch who happened to melt all my palladium sponge in the past succesesfully, witnessed the whole melting process and resulting button was just puzzled me, only 6g of impure palladium, wth??

To percipitate that amount of palladium sponge, I used zinc percipitation and some of the solution I used DMG percipitation and in all of those I used 10% hcl plus zinc powder to convert the yellow salt to palladium sponge, I even dissolved a gram of it in nitric acid and got strong Pd peresnece upon using stannous chloridd test.

A sample of the same palladium black powder weighing 0.3g was added on top of 2g rolled palladium metal, and melted in a vaccummed induction furnace and it produced 2.5g button that was contaminated with carbon as the crucible in the induction furnace was graphite. But it still looked like a brittle palladium.

I read and tested at least 5 times that whatever the amount of palladium sponge was once melted it should produce very similar amount of palladium metal. But over 76g of loss I mean what could those powders be? Did they evaporate? Most of it turned to dark greenish slags on the melting cruicble.

I am confused, could it be the DMG or zinc that I used were contaminated??

When I do my palladium purifications, I'm going to be using a formic acid-carbonate method after dissolving the impure metal in nitric acid, that doesn't require any metal for cementing. You can look up the protocols for it online. I've watched several videos of people using it, with very detailed steps. When done correctly, the formal protocol found consistent results with a 97% recovery on average with no risk of contamination from other metals (one article from a scientific journal found the purity to usually be 99.7%). It works extremely well with the silver-palladium capacitors, ceramic-coated foil type or MLCCs (burned and powdered first). I've seen some recovery from those reach 99% of the calculated recovery.

The advantages of formic acid are that it's relatively cheap, and it can be broken down completely afterward to CO2, chemically or thermally, and therefore the waste is easily turned into a dry powder of metal oxides and carbonates. If the recovery fails, you can STILL do this drying and roasting step, then try again. You won't lose any metal, or keep adding metals. The only things being added are formate (the simplest carboxylic acid) and sodium carbonate, neither of which will contaminate the final product.

And formic acid, though 'dangerous', is much less dangerous than the concentrated nitric acid or sulfuric acid you're likely using anyway.