Always iron in final material ????

Gold Refining Forum

Help Support Gold Refining Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

goldfever007

Active member
Joined
Mar 22, 2018
Messages
39
Dear members :
I was refining gold foils from old memory ship and other plated gold stuff , i used Aqua Regia to dissolve the material.
So like usual i neutrelize the acid ,precipitate the gold with copperas , then i washed the material and i end up with this...."photo bellow"
The problem is when i melt the final material with borax i get gold with iron and little of copper...??!!!!
Could anybody tell me why?and what should i do?
Thank you guys.
 

Attachments

  • image-0-02-04-ea3a26c28592a99deeb1bc0059b467be569add282cbd16f3193241bed63c291f-V.jpg
    image-0-02-04-ea3a26c28592a99deeb1bc0059b467be569add282cbd16f3193241bed63c291f-V.jpg
    120.6 KB · Views: 148
Have you considered your filters may be allowing tiny amounts to slip through?
Are you processing gold plated items with AR?
 
There is a good chance you are bringing down the copper and iron from the solution which is likely saturated with metals other than the gold you started with. What color is the acid when you add the copperas? What color is your copperas? And finally, how are you "Neutralizing" the acid?
 
What do you mean by "Always iron in final material" ?

Does that you mean you Always get a filter paper full of iron oxide/hydroxide sludge, or chocolate, which is what the photo looks like ?

Edit:

Looking closely is just chocolate. It's xxxxxx
 
What type of material was the "other gold plated stuff"?

4metals said:
There is a good chance you are bringing down the copper and iron from the solution which is likely saturated with metals other than the gold you started with.

This was my first thought also. Possibly large pieces of gold plated "magnetic" jewelry or a handful of gold pins from circuit boards could explain the iron, depending on how much solution was used.

aga said:
a filter paper full of iron oxide/hydroxide sludge, or chocolate

That does look like some form of iron oxide to me. The same color is used for paint, cosmetics, etc.

https://en.wikipedia.org/wiki/Iron_oxide#/media/File:IronOxidePigmentUSGOV.jpg (if the picture doesn't show up, scroll down a little, it's the one with a penny beside it.)
 
4metals
What color is the acid when you add the copperas?....yellow.
What color is your copperas? ......................................green.
And finally, how are you "Neutralizing" the acid?.........urea .
Can i refine it again with AR ? could that solve the problem?
 
Try washing your powders, first put into a beaker and add water and boil for a good 30 minutes, you will need a watch glass over the beaker, this should remove some impurities which should be obvious by the color of the water, pour the water off and add Hcl and again boil it with the watch glass over, this should remove more impurities so you may need to do this several times decanting off the acid to use for the next dissolution. Rinse the powder several times with hot water and again put a decent amount in the beaker and give it another good boil.
The iron you are finding is from the copperas and is probably from undissolved crystals while the copper is from drag down but it should all be removerable by decent washes.
 
The color of your copperas is good, the crystals should be green.
ferrous sulfate.jpeg
And urea will consume free nitric, not the best choice but not your problem now.

The color of the solution seems consistent with AR used to digest clean foils which can be yellow to red.

I am confused as to how you processed the gold electroplated material, from your post I assumed you dissolved the entire piece in AR but the color does not indicate that. Did you dissolve away base metals to get gold foils from the plated material?

Before you added copperas I assume that you checked for gold with stannous chloride, did you check after as well?
 
Back
Top