DMG vs palladium chloride
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It will work in chloride solutions too.
As with stannous chloride, you should always have a "standard" solution that is known to contain your target metal. For stannous, you want a solution with gold in it. To check your DMG solution, you should have a solution that you know contains palladium. You only need a small amount because you only use it to check your DMG solution when it isn't reacting the way it should.
If you don't happen to have any palladium sitting around, you can also use nickel. In the U.S., our 5 cent coin, called a nickel, is made from 75% copper and 25% nickel. I'm sure you can find something similar. File a bit off, catch the filings and dissolve them in a few drops of nitric acid. When the metal is dissolved, add several drops of ammonia to the solution. Then add a drop or two of your DMG solution. If it's working, you should see the solution turn a pinkish red. If it doesn't, add some more ammonia. If it still doesn't turn pink to red, I'd wonder if your DMG is not working.
Dave
As with stannous chloride, you should always have a "standard" solution that is known to contain your target metal. For stannous, you want a solution with gold in it. To check your DMG solution, you should have a solution that you know contains palladium. You only need a small amount because you only use it to check your DMG solution when it isn't reacting the way it should.
If you don't happen to have any palladium sitting around, you can also use nickel. In the U.S., our 5 cent coin, called a nickel, is made from 75% copper and 25% nickel. I'm sure you can find something similar. File a bit off, catch the filings and dissolve them in a few drops of nitric acid. When the metal is dissolved, add several drops of ammonia to the solution. Then add a drop or two of your DMG solution. If it's working, you should see the solution turn a pinkish red. If it doesn't, add some more ammonia. If it still doesn't turn pink to red, I'd wonder if your DMG is not working.
Dave
It will work also from chloride media, but be aware of a fact that if you do not have de-noxed solutions of AR or leftover nitric (worse), DMG start to decompose in these, and fact is also that Pd(DMG)2 complex too.
DMG is much more soluble in BM nitric solutions than in chloride media. So if you use it as solid powder instead of solution, you need to effectively stir the suspension in chloride media for quite a bit of time to achieve full scavenging.
DMG is much more soluble in BM nitric solutions than in chloride media. So if you use it as solid powder instead of solution, you need to effectively stir the suspension in chloride media for quite a bit of time to achieve full scavenging.
Yeah, of course you can. I like this approach, as it does not add "dead" volume to the solution, thus less volume of waste produced. But you should be aware of a fact that this essentially "adsorption of Pd onto solid" takes time. DMG is quite hydrophobic and very low solubility in chloride base metals solutions like AR after gold drop.So you can add the DMG directly to the solution?
Interesting
So efficient stirbar, good rpm's and stirring for several hours is the way I do this. From nitric solutions, it is wise to kill the remains of nitric by addition of more silver or simply neutralizing it with NaOH to the point it flips to the positive pH range
like pH 1 is relatively fine.Then you add DMG with vigorous stirring, watching how it mostly dissolve and in matter of seconds yellow voluminous Pd complex precipitate. Let it stir for half hour or so, and filter. Test the filtrate with new, fresh bit of DMG, if the precipitation was complete. If it was, clean filter paper with few specks of white DMG will be obtained. If some Pd was still in solution, you will clearly see yellow very fine ppt on the filter.
What should be the PH of solution when using DMG for palladium? I used DMG when solution ph was 1. Should DMG work at this PH? I got light pink powder at this PH.Although Nickel is in the solution. By going through forum I think PH should be between 4 to7 for palladium to be precipitated out by DMG. Is this right?
Thanks
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