Unknown Un-melting material

[elfixx]

Big mess.....
I bought some silver (already melted scrap)on ebay to inquart some gold and process in nitric a cople week earlyer and I received it today. In a hurry i melted what i beleved to be silver and some 14k gold. The silver looked dirty but I didn't realy pay attention. In my crucible some of the metal wasn't melting properly it instead formed a brown/grey crust on the metal and at the bottom of my crucible. I putted all of this in 150ml 70% nitric and 50ml of distiled water and boil it for 3 hour. I had 47g of 6k material and ended up with a lil bit more than 25g of dirty gold/litle bit of silver/brown dirt metal. I can't figure out what is that material forming a thick crust over the metal and how can i get rid of it to be able to process my gold into AR.
Please help me

 

[Harold_V]

Check it with a magnet for one. I think you got snookered by some stainless mixed with silver. That's very common, especially if you got chains in the lot you bought.

It may or may not be magnetic (300 series stainless is non-magnetic unless it is work hardened. The heating it experienced would have annealed that condition), but now that you've got things mixed by melting, you're likely going to have to dissolve the lot and precipitate the gold to get it away from the unwanted metal, what ever it may be.

Before you try that, why don't you give the entire lot a boil in HCl, or even sulfuric. That may dissolve the unwanted material, but if they have alloyed, you're likely still going to have to resort to AR.

Regardless of what procedure you try, be certain to test all of your solutions before discarding. You may dissolve a trace of gold by making the change to HCl from nitric. Also, any fine particles that may result should not be discarded. They may be gold, but not look like it.

Does any of this help? Do you need step by step instruction?

Harold

 

[elfixx]

thanks a lot again for those info, and no thx for the step by step im getting used to work with those chemical
And by the way this forum is AWESOME
Merry christmas to every member