Gold purity 99.9 % but the color of gold is greyish when heated

[grainsofgold]

You can soak the button in jewelers pickle this will clean the surface. Best to do once the button hardens and is still hit drop it in warmed pickle. sparex is a brand of pickle , some use Ph down used fir swing pools.

Once the surface is cleaned re melt it in a clean crucible with a clean flame from your torch and then see how it turns out. If the surface dark re refine it.

 

[MyNAmeIsU]

There is some info lacking here:
What was the source?
How do you know the purity, before and after refining?
Why did you use Urea?
Which Gold reagent (precipitant)?
How did you melt it?
With or without Borax?

And please do not use lingo like u here.

Edited to eliminate profanity and rules violations - FrugalRefiner

 

[Yggdrasil]

Post deleted

Welcome and maybe goodbye!!!!
You just broke most of our rules.
Unless you shape up significantly you won’t last long.

 

[FrugalRefiner]

Nope! He obviously has no intention of following the rules. He's gone.

Dave

 

[galenrog]

I missed the show again. How disappointing.

I do, however, congratulate Dave and Yggdrasil for dealing with the trash appropriately.

Time for more coffee.

 

[FrugalRefiner]

Just a schoolyard bully who needed to use profanity and show his defiance for rules.

Dave

 

[galenrog]

Just a schoolyard bully who needed to use profanity and show his defiance for rules.

Dave

I figured that. Still, would have been an entertaining show. I would have even made popcorn.

Time for more coffee.

 

[Justincase]

This may be a bit of a tangent for you.
But the South Americans very rarely actually used pure gold but all their artifacts look like pure gold.
This was because they had a very high copper content.
They then would oxidize the copper and use Alum to remove the copper oxide leaving a high gold content surface for people to see.
So Alum should remove the gray copper oxide if need be.

 

[troyjgp]

sorry I missed the show was stuck in the Houston airport for 36 hours waiting for AirCanada to fix my flight talk about a long flight to Ottawa lol. I'm new to this amazing site and will be searching through the vast knowledge on your amazing site figure out how to fix my big mistake I was given nitric acid for my work to use but never realized it was full strength nitric acid. Glad to be here so many very knowledgeable people here. So glad I found this site

 

[David Phelps]

Thanks for replying ,
I am using the same method of heating everytime , thats why i am certain that its not because of heating
i got it assayed through xrf
I am attaching the picture . The one on the left is heated without dipping in water and without using borax , and the other one is after turning it to shot.
Both the pieces are of the same metal refined.

Thanks

gold takes hydrogen to reduce to it's normal state, the gray gold is an oxide state. dropping melted gold in water gives it hydrogen so will slow roasting charcoal as charcoal does both oxidation followed by hydrogenation the process is carboxylation. I roast my gold ore 900 degree 4 hrs then dry smelt metal out of the rock at 1100 degrees this grey metal comes out the rock all the time. either let it set a year or attempt carbon roasting. they said back in the 90's large refineries would cast loaf bars weighing 70 lbs and would store them under water for a year to cure. they do it differant now i think. hard to find loaf gold. which i'm having problems with reducing some my greys as i can't tell what has copper in it and what don't. epa said i can't use acids, only leaves chapman flux.

 

[Yggdrasil]

gold takes hydrogen to reduce to it's normal state, the gray gold is an oxide state. dropping melted gold in water gives it hydrogen so will slow roasting charcoal as charcoal does both oxidation followed by hydrogenation the process is carboxylation. I roast my gold ore 900 degree 4 hrs then dry smelt metal out of the rock at 1100 degrees this grey metal comes out the rock all the time. either let it set a year or attempt carbon roasting. they said back in the 90's large refineries would cast loaf bars weighing 70 lbs and would store them under water for a year to cure. they do it differant now i think. hard to find loaf gold. which i'm having problems with reducing some my greys as i can't tell what has copper in it and what don't. epa said i can't use acids, only leaves chapman flux.

Welcome to us.
Pure Gold do not react to any single acid or heat.
Slags and contamination react with the Oxygen/Carbon in its environment and form different compounds.
Often on the surface.
No refinery or other industries store values like this over time.
What you are referring to is probably Dore bars which is a mix of precious metals like Gold and Silver and base metals.
These are sent off to refineries for refining.

 

[Southfork]

Because I use dirty melt dishes my buttons have a grey coating. I use cleaning vinegar soak for a few days and wipe place back in until clean slow but cheap.