Gold specles in precipitate

[martymcfly]

Ive only just done my first re-refining of my gold precipitate and there appears to be specles of gold mixed in with my precipitated powder, Is this the result of contamination of some sort or completely normal?

thanks in advance.

 

[niteliteone]

Ive only just done my first re-refining of my gold precipitate and there appears to be specles of gold mixed in with my precipitated powder, Is this the result of contamination of some sort or completely normal?

thanks in advance.

Could be salts in solution that crystallized along with your precipitation.
Would need to see the whole process steps and what material is in their to be able to offer a better answer.

 

[martymcfly]

Ive only just done my first re-refining of my gold precipitate and there appears to be specles of gold mixed in with my precipitated powder, Is this the result of contamination of some sort or completely normal?

thanks in advance.

Could be salts in solution that crystallized along with your precipitation.
Would need to see the whole process steps and what material is in their to be able to offer a better answer.

I put my already precipitated gold powder from ceramic cpus into A/R and used some gold foils from ram to finish of the nitric reaction, used ice to force out the silver and then filtered, Dropped tthe gold with smb. Have now drained of the solution but not yet done any washes to it.

 

[kkmonte]

I know you said you filtered it, but do you think its undissolved gold foils? or did all of those get filtered?

 

[JHS]

sounds like not all your foils desolved and sliped past your filter.
john

 

[niteliteone]

Ive only just done my first re-refining of my gold precipitate and there appears to be specles of gold mixed in with my precipitated powder, Is this the result of contamination of some sort or completely normal?

thanks in advance.

Could be salts in solution that crystallized along with your precipitation.
Would need to see the whole process steps and what material is in their to be able to offer a better answer.

I put my already precipitated gold powder from ceramic cpus into A/R and used some gold foils from ram to finish of the nitric reaction, used ice to force out the silver and then filtered, Dropped tthe gold with smb. Have now drained of the solution but not yet done any washes to it.

As the others have mentioned, check your process to see if something could have gotten past the filter to be on the safe side.
By A/R, I assume you mean the traditional HCl + Nitric and not a "poormans" variation.
If all looks good, then;
Add 10-25% additional water and a little heat to the solution and stir to see if the crystals will dissolve. Many times I refine, I have had salt crystals form, as I work with slightly concentrated solutions.
Also, by adding the gold foils from the ram, a little lead could have made it into solution, but will be removed with the water and heat addition.

 

[martymcfly]

I will continue the process and boil in water to see what happens. I had considered the filter but iwhen I checked the filter it had caught all the silver but couldn't see any of the speckles in the filter. It looks like they appeared after /while precipitating.

Also my A/R is hcl/nitric not poormans.

 

[butcher]

It is rare, but I have precipitated gold as very fine gold (gold colored) fine powder.

 

[Harold_V]

What Butcher said. In all my years of refining, I witnessed that very thing no more than a few times. It's unusual, but gold can come down as crystals. They'll be dense and settle quickly, although not all of the gold may come down that way. I was never able to create the circumstances on purpose, nor did I understand why it happened.

Harold

 

[rickbb]

I've also had gold to form on the sides of my beaker and then drop off into the solution. This is from a not really clean beaker or having fine scratches from aggressive cleaning.

 

[Anonymous]

Did it look anything like this as it was precipitating? Sorry it's side on, I don't have a photo editor on my work PC.

If you blow up the picture you can see the particles clearly.

 

[philddreamer]

I've also expirienced gold crystals, and have also been able to repeat it several times. This has only happened when I've used the sulphuric cell.
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=61&t=14808&p=149849&hilit=gold+crystals#p149897

Sodium metabisulphite has been my precipitant. I think, and this is my assumption since I'm not a chemist, that the presence of sulphuric acid has something to do with the large amount of gold crystals. I only get fine gold crystals floating on top when I've used other processes like AR or HCl/Cl, but when a fair amount of sulphuric acid is present, that's when theheavy gold crystals show up.

Take care!
Phil

 

[martymcfly]

I didnt actually watch it precipitate, it was just when i went back to it. I think the gold may have been floating on the top but i certainly never noticed it before i precipitated, This was the first time ive had A/R so clean that i could actually see what was going on. I havent had time to do the washes yet but before i do i will try and get a photo up to show you what ive got at teh moment.

 

[Palladium]

On occasion i have had gold precipitate as a few crystals mixed in with the powder also.

 

[RGJohn]

Ive only just done my first re-refining of my gold precipitate and there appears to be specles of gold mixed in with my precipitated powder, Is this the result of contamination of some sort or completely normal?

thanks in advance.

You say that this was a 're-refining'. Did either refining involve oxalic acid?
----
I ask because I once, using techniques that I cannot exactly quantify ( freehand stuff I performed before realizing the importance of system, consistency, and record-keeping.... in other words, benefitting from the experience of those who post here), I too had a precipitate which basically appeared to be free flakes of gold. Not that finely powdered brownish stuff one obtains from SMB but gorgeous, shiny, flakes of gold. I used oxalic acid crystals to precipitate and whatever I had going on in there (AR digestion), free gold flocculant ( large irregular shaped but otherwise snowflake-like pieces of gold ) FILLED the beaker, then settled. Settled rather well too but before it did, wow! what a show!
--------
Is that the kind of thing which you observed?

 

[Anonymous]

Do you mean similar to my pic up there John? ^^^^^^

That drop was HCl/NaClO dissolved, and precipitated with SMB after warming the solution and venting off the chlorine for over an hour. The solution was also warm when the SMB was added. Both the acid and bleach were lab grade product. I'm throwing all this additional info in to hopefully find some common ground with other people who have seen this happen and maybe find a link.

It was (like yours) one of the cleanest drops I ever did.

Maybe it's a purity thing? Maybe not, but it would be good to find out.

Regards

Jon

Edited for correctness.

 

[martymcfly]

both my drops i used A/R Hcl/HN03 and both times i dropped with smb. If its a purity thing then its probably gold thats not too pure beacause i doubt mine is super pure =p

 

[philddreamer]

If its a purity thing then its probably gold thats not too pure beacause i doubt mine is super pure =p.

I had .990 gold crystals from dirty HCl/Cl that had sulphuric acid from the cell, processed only once. All the chemicals used were from hardware stores. I will try next time and process a second time, just to see if I get the gold crystals. I will be adding a bit of sulpuric acid to see if its presence is what triggers the gold crystals... :roll:
I'm sure that having a cleaner solution will drop a cleaner gold, especially if using oxilic acid, but why gold crystals from a dirty solution!?

I posted some of the videos on youtube some time ago of the several drops, (I was able to repeat the crystals 8 times in a row, and all from dirty solutions):
http://www.youtube.com/user/dpmrecycler

Phil

 

[Anonymous]

Given that I didn't use any Sulphuric, it can't be the sole trigger Phil.

 

[Anonymous]

Had a play round this afternoon when we'd finished the main drops, with the "clean up" from the fingers stock pot and we managed to get this to happen. Took a few different tries but it worked in the end. We didn't use any H2SO4 Phil however the method we used to get the crystals points more to a purity thing.