# cleaning sweepings



## buckdec (Feb 4, 2012)

so i have gathered about 50 lbs of sweepings and wondering if anyone would have any suggestions for seperating it. it consists mostly of brass brazing wire that is 50% silver and other stuff and most of the rest is powdered steel dirt and flux. i was wondering if anyone has a good way of seperating it. ive played with it at work were i just melted it all down with oxy acetelene in a peice of angle iron and the majority of contaminents burned off and the brass pooled together at the botttom. iv tryed mapp gas small torch and it wouldnt burn the dirt off and want to make sure there isnt a better way before i go out and buy a oxy acetelene set up for at home.


----------



## butcher (Feb 4, 2012)

I would try panning, and using a magnet to separate, I think leaving this in small beads is an advantage, incinerating to red hot but not melting, now you’re saying this is brass and silver?
What percentage of silver, and this brass? Copper and zinc? Or is this some type of silver solder?

Silver content can make a difference if base metals can be leached with an acid peroxide solution or if nitric acid would be a better choice.


----------



## buckdec (Feb 4, 2012)

It's slag from brass brazing wire that is 50% silver 45% copper and 5% zinc. And i have tried nitric cemented with copper and it worked really well on just wire ends. So if u heat to red hot you can just put all the dirt in the nitric or is there a step I'm missing?


----------



## butcher (Feb 4, 2012)

Magnet to separate bulk of any iron, pan off as much dirt as possible, and incineration red hot, to burn off oils, paper, trash, other carbonous materials, and nitric acid would be my choice. The high percentage of silver nitric would be my choice.

You can incinerate on electric hotplate with propane torch with beads in a casserole dish stir to mix while incinerating hot water wash after cooling, and then I would possibly dissolve the beads with heat, starting with a some what dilute nitric and my beads on a hotplate in a casserole dish, heating the nitric dissolving as much beads as possible, using decantation of hot solutions to cooling jar (letting salts form), returning liquid back to heating vessel, (adding some fresh dilute nitric when needed, but this nitric would be first added to these salts in the jar,(cleaning them up) before this nitric is being put into heating vessel, to dissolve more beads) this is hard to explain, here your beads help to cement silver, as they dissolve, you also clean your cemented silver some with fresh acid that will pick up more base metals from the salts, and then from the beads your dissolving, actually I do this same type of a thing with different materials, and I may have four or five jars of powders in different stages of being upgraded.

I know that I did not explain this very well, I hope you get the Idea of what I am trying to say.


----------



## buckdec (Feb 8, 2012)

So I tryed the magnet and it actually work to well in the fact that most of the sweepings is a very fine steel dust that it picks up some of the brass with it.


----------



## nickvc (Feb 8, 2012)

Butcher gave you the best advice,as I expected, all sweeps are a pain to treat there is no simple one step way to treat any of them. You may have to use the magnet several times to separate the steel from the silver solder, it might pay you to incinerate your material in small batches to remove as much junk to start and then run the magnet through your material, spread it out well so as much of the solder is in the open as possible so the magnet can pull more steel and less solder bound in with it. The discarded steel will almost certainly have some solder mixed in with it but you can re run your magnet over it at leisure once you have the vast majority of the solder ready for dissolving, remember the values are going nowhere unless you throw them out. It's going to take time but I'm sure you will recover the bulk of the values with a little patience and will be holding a nice silver bar or two in the very near future.


----------

