I have brought big volumes of silver to a lot of different refineries and have had mixed results...I feel very comfortable in my testing, so I guess my question is how much is typically lost( weight) in lets say a 1000 toz melt If all weights stones, ect are removed...Any help would greatly be appreciated...Thanks in advance!
How much should be lost in a scrap .925 melt???
- Thread starter afbrianh
- Start date
Help Support Gold Refining Forum:
I think the answer here is it depends. clean scrap should loose little as in under 1% but sterling silver and jewelry can have losses quite high. I've seen sterling come in and have all of the knives separated as well as the filled handles removed and have melt losses as high as 15%. Now as a former refinery owner that would raise my eyebrows but I have seen it on melts that I did.
I'm with 4metals here the losses can vary tremendously and the only way to be sure of true results is to melt the material yourself and get a feel for what the expecked losses should be. I have also found that in my experience sterling rarely assays at 925 mainly due to the solder used I think and an assay of 915 woils be average.
element47
Well-known member
I have experienced losses on carefully separated materials I have submitted for refining but I thought it was, let's just say, something that only seems to happen in the Midwest. 15% is outrageous, though, for whatever reason. I've never had it go that high, but I have had 2-3% on lots of pure forks and spoons, no knife handle nonsense, no solder, strictly forks-spoons, all solid.
If you're having melt loss like that, then the purity must go up because copper is being removed from the alloy.
Bear in mind that silver is also considerably more volatile than gold or platinum and has a vapor pressure, but that will not account for 15% melt loss unless the material was quite dirty.
Clean sterling like element47 was melting should not have more than a percent (at the tops) of melt loss.
Half of the issue is that people who complain about the melt losses have never melted sterling.
If you have, you've noticed the skin that forms on it when melted in atmosphere. This skin is copper oxide.
It should not be skimmed because some of the silver will go with it. It should be entrained in slag and removed that way instead.
Bear in mind that silver is also considerably more volatile than gold or platinum and has a vapor pressure, but that will not account for 15% melt loss unless the material was quite dirty.
Clean sterling like element47 was melting should not have more than a percent (at the tops) of melt loss.
Half of the issue is that people who complain about the melt losses have never melted sterling.
If you have, you've noticed the skin that forms on it when melted in atmosphere. This skin is copper oxide.
It should not be skimmed because some of the silver will go with it. It should be entrained in slag and removed that way instead.
