scrap silve jewelry refining Questions

[Zabrunski]

I am really new to refining gold/silver i have all the glass wear, chemicals, fume hood. so today i decided after too many hours of research to count, refining some scrap sterling. I began by adding approximately 200 ml of 93% sulphuric acid to 160 grams of sterling scrap. after applying heat for about an hour all I have is really shiny silver scrap and a really dark brown/black solution.

I'm at a loss, and have no clue why it has turned to such a color. for a test I poured off 10 ml into a separate beaker and added hcl and was shocked to find no precipitated silver. has anyone any advice?

 

[Lino1406]

Maybe the silver is rhodium plated? Try to dissolve a sample in nitric acid

 

[Zabrunski]

what results would I be looking for?

 

[Lino1406]

If nitric does not dissolve too, then it may be rhodium plating (or stainless)

 

[Zabrunski]

well after about 1.5 hours i pulled off from the heat. drained out the sulfuric into a seperate beaker, and found that all the pieces of sterling were incredibly clean and shiny. did i maybe just not incinerate well enough? or was it working and i just worried it wasnt?

 

[Geo]

Sulfuric acid is not a very good chemical to dissolve silver with. It works better on thin pieces or fines. It would take days to dissolve an appreciable amount from heavy solids. Where did the idea of using sulfuric to dissolve silver come from. Kevin made a video of using it on some candle stick pieces but it was already very thin pieces and in the video, it took a very long time. I think it was just to show that it could be done and not a recommendation that it should be done that way. Get some nitric acid, make some or work with something else.