Silver wool

[MGH]

In the lab where I work, one of the instruments uses silver wool as a reagent. Yes, pure silver, very small diameter wire. There's no coating, as this would defeat the purpose in this application. Some of the wool gets heavily oxidized (plus some other chemistry going on which I haven't done enough homework yet to be able to explain), and some of the wool stays pretty clean. Here's 10 grams of the clean stuff that I simply melted into a button.

Of course it's not the prettiest button of silver there ever was. My melting dish has too much flux in it (and I didn't want to break out a new one for this), and I'm just working with MAPP gas, pliers, and a pot of water for quenching. It's smooth on the bottom and textured on the top. Anybody know if this is mainly related to having too much flux, the type or torch, or anything else? Open to critiques.

I have another 10 grams of the dirty silver wool digested in nitric acid along with a sterling silver ring. I've left it to filter for the night. Just planning to cement with copper, wash, and melt. That will be my first actual refining of silver.

-Matt

 

[jmdlcar]

That is nice silver button.

Jack

 

[Geo]

Matt, far from me to judge but if this is used as a reagent in the lab where you work, wouldnt it be worth more for its intended use than melting it? im sure you got it legally and it wasnt pilfered from the stores where you work.

 

[MGH]

Geo, absolutely it's worth more for its intended purpose - before it's used. After it's used even though some of it still looks relatively clean, it's not worth risking the time of changing all the reagents again and the quality of the data reported to save a few bucks on the wool. We're as frugal as we can be in the lab, but data quality comes first, and a few grams of decent scrap is sometimes the result .

 

[ilikesilver]

MGH how well did it melt? it looks so fine, was it easy

 

[nickvc]

If the wire is not contaminated by metals in the lab I'd bet it was fine metal so just melting it should yield you 999 silver if melted in a clean dish, by dissolving and cementing it you will lower its purity.

 

[MGH]

MGH how well did it melt? it looks so fine, was it easy

I suppose it was a little easier than melting powder. Any filament that strayed away from the bulk of the mass melted very quickly and fell down to the dish or on top of the rest of the mass. That all happened quickly, but then you still had a lump of silver there that melted just like anything else. The best part was not having to worry about blowing powder out of the dish.

If the wire is not contaminated by metals in the lab I'd bet it was fine metal so just melting it should yield you 999 silver if melted in a clean dish, by dissolving and cementing it you will lower its purity.

Nick, that's my thought exactly. When it's dirty, it's defintely dirty and needs refining, but I simply melted that wool in picture directly. I did get a couple more plugs of the clean material, and this time I was wanting to do a simple wash just to make sure. I was thinking of washing with ammonia to remove oxides and any AgCl that might be on the surface. Anyone have any other suggestions or corrections? I'll try a test sample on a smaller portion anyway.

-Matt