Silver and copper cell?

[FrugalRefiner]

Your DMG is probably fine. It just isn't very soluble in water. I've never gotten a full gram to dissolve in 100 ml either.

Dave

 

[kurtak]

autumnwillow

When preparing DMG with just water yes it is normal to re-form a precipitate after cooling - filter it & it should be just fine

However for future reference when preparing your DMG use a little NaOh to prepare it --- doing so will help the DMG dissolve faster & more complete - here are the instructions -------

For every 100 ml H2O use 5.81 grams DMG & 4 grams NaOH --- bring the water to boil & then add the DMG & the NaOH - it takes very little time for the DMG to dissolve with the NaOH added - you will still get some precipitate that forms after cooling but no where near as much - so you still want to filter after cooling

Because of the NaOH when you prepare you DMG this way - when you first add the DMG to your acidic solution the NaOH will form a hydroxide precipitate but that goes right back into solution due the acid concentration being the greater factor

In other words the little bit of NaOH being used to prepare your DMG this way is not enough to effect the PH so that a hydroxide precipitate is formed & stays formed - the acid over comes it & re-dissolves it "quickly" --- but the DMG still does its job of precipitating the Pd

Kurt

 

[4metals]

I use DMG in an NaOH solution as well and Kurt is right, the acidity of the solution is USUALLY sufficient to maintain the acidity and drop the Pd. But, (seems there's always a but in refining) sometimes if you use too much DMG solution or the acidity of the mother solution was weak you can drop Nickel from solution if it is alkaline.

I am a strong advocate in experience in refining, having seen a reaction first hand is a great learning experience. So I think it is helpful to make up a solution with a little Pd and a little nickel in it. Drop half of it while maintaining an acid pH, then drop the other half from an alkaline solution. It is good to see first hand what the nickel DMG compound looks like for future reference. There will be a time when your pH goes alkaline and you have a moment when you are scratching your head wondering what the heck happened. Knowing what nickel dropped with DMG looks like will be helpful.

 

[autumnwillow]

So what is this white precipitate?
Should I just throw it away after filtering or is this DMG that I could probably try re-dissolving with a little NaOH plus water just like what kurtak said?

I have filtered it and tested with my greenish nitric solution and got a yellowish cloud. I think I need more.

Thank you guys for your help and happy new year!