hey guys my name is Jason with Mount Baker Mining Metals and on today's video we're
gonna be looking at recovering silver from some lead wheel weights I got these
from the scrapyard you can take a look here these are the things that clip onto
your tires to help balance them and these are typically lead there's a
little bit of antimony in there I think to harden them up some of the newer ones
might be zinc so my plan is is I'm gonna clip off little bits of a bunch of
different wheel weights so we can get a pretty representative sample and then
I'm gonna take about 300 to 350 grams I'm gonna put them in this magnesia
cupel here and what this does is when you heat up the metal the lead melts at
about 650 degrees Fahrenheit and then the surface of the lead bead or button
starts to oxidize and when we raise the temperature up higher to about
1650 degrees that lead oxide layer starts to melt and shed off in to
the cupel and the cupel absorbs it like a sponge and so as the lead oxidizes it's
continuingly shut off absorbed into the cupel the lead metal itself is
impervious to the cupel and so as this reaction continues the button gets
smaller and smaller and smaller and this cupel fills up with the lead oxide and
you're left with the precious metals in a little tiny bead right in the center
and the precious metals stay because they won't oxidize so silver, gold, any of
the platinum group elements they don't oxidize all the other base metals the
antimony, copper, lead, iron will all oxidize in this process and be absorbed
in the cupel so let's get started here I'm just going to take some tin snips
and I'm just gonna take the wheel weights and I'm gonna just clip off a
little corner just a little bit of the lead and I'm gonna do that for several
of them get them weighed out on a scale and once we get about 300 to 350 grams
we'll put them in the cupel and we'll get them in the furnace and we'll start
and driving the lead off
gloves!
the the lead is so soft and the wheel weights
are thin enough that I can just nip them off pretty easy and it's actually
amazing you can tell just by cutting them some of them are harder and some of
them real soft so again I can tell just from how hard it is to trim them that
the chemistry might be a little bit different across the range of these
wheel weights that somebody asked me the other day on on one of our videos if you
can recover silver from lead and so this is a little experiment to see if that
works but I've been doing a lot of smelting videos lately and one of the
important parts for like an assay or when you're analyzing how much gold
you've recovered is you want to make sure that you know the impurities in
your collector metal if you have any such as silver and so the idea here is
take your lead run a blank cupel and find out how much silver weight you have
just residual in your collector metal and then when you get your bead from
your smelt or your assay you have to subtract the amount of residual silver
that's in your collector metal so that's that's kind of
the bigger picture here on what we're doing and we're taking a little bit off
of each wheel weight so we can get kind of a representative sample because if we
just melt it down three wheel weights there might be no silver in
those or it may be full of silver so again we kind of want to get a
representation of a bunch of different wheel weights
there's all our lead pieces right there so we'll take these and get them weighed
okay there is there's 300 grams of wheel weights here's our cupel full of our
lead and now we'll go get our electric furnace set up and get this melted down
and up to temperature to shed those oxides and here's our lead in our
furnace this is a little electric furnace and we have exactly 300 grams in
there and it looks like a lot I know this cupel is rated for 400 grams 380
or something so all that should melt down and not overflow hopefully as you
can see I've actually spilled a little bit of lead in this furnace as lead oxide
is real corrosive and it eats up this this kind of foam insulation pretty bad
so you want to make sure you don't spill lead all over your furnace because
that's bad but we'll get this heating up it heats up pretty fast and then we'll
melt the lead and we'll check back in on it once the lead's molten so I'm just
going to close the door and when we do get up to temperature and the lead oxide
melts I'll crack this door a little bit and allow the oxygen from the air to get
in and oxidize the lead if you keep the door closed the oxygen doesn't circulate
very well and it takes forever so we'll let that heat up and check back on it in
a minute all right so we're molten alloy we uh we almost overflowed there but you
can see it's got that kind of black scum on top that's the let oxide that's
formed but it's not molten yet and we're only well I opened the door so it's
cooling down but we're about 1500 degrees so and a couple more hundred
degrees that hopefully will start driving in the cupel the cupel will
turn kind of a dark grey or black Brown looking thing
so we'll get that up to temperature here and check back on our cupel's starting
to absorb some of that lead you can see the gray spot on it and when it first
went molten there was a bunch of junk on top and so I kind of scraped it off to
the sides you can see it all there and I think that's probably oxides from some
of the other base metals like iron and copper and stuff so those those won't
melt when there's a whole bunch of them like that the lead can't get them all
into the cupel so I scraped them off it looks like we got a pretty good lead
bead going on there and it's drawn down into the cupel so we'll let that go
it's been about 45 minutes or so now so we'll let it go and it'll probably take
an hour or two to run all that lead in but we're running right at 1700 degrees you
can see the furnace heating back up again since they open the door but we're
on our way so we'll see what kind of bead we get in
the bottom of that cupel okay so I just switched cupels here there's the
one that was going and it was getting pretty well to the bottom it actually
had gone to the bottom here and I was a little worried about it getting stuck on
the little plinth I had in the furnace so I moved it over to this one and this
way it looks pretty junky so there might be some zinc in there or
something else you know it's it's it's not really great looking but we'll keep
cupelling it get it all the way down to a precious metal button hopefully and
see how much silver we have in there and here's that first cupel and like I
said earlier you can you can see there's a ring a junk around the top and when
the button first went liquid and got up to temperature all these all this junk
floated to the top and my guess is is that's all other base metal oxides other
than leads so you know maybe a little bit of copper antimony maybe some iron in
there but it's just all the rest of the junk that was in there that probably has
a higher melting point than what we were reaching in our furnace so what I did is
I just took a little piece of wire and I just I scraped it all off along to the
sides so so the lead could get a metallic surface
to the air and start to oxidize once I got the lead exposed it could start
cupelling and then the button started to shrink pretty quickly so thought that
was an important part to this whole this whole silver recovery is you know
there's a lot of a lot of stuff in those wheel weights other than just lead
alright we'll check out our cupel here should be getting pretty close oh yeah
so are almost done there another a couple minutes at the most and we'll
have a little bead in there hopefully all right I just pulled the cupel out
and there's our little bead right there looks like it's got some oxide junk on
that right-hand side but let me let me get the tweezers and pull it out of
there and see if we can get it weighed but cool we got silver from from wheel
weights there's our little bead and it looks like it weighs 0.04 grams so we
recovered 0.04 grams of silver from 300 grams of wheel weights so as
you can see there's not very much silver left in wheel weights we only recovered
0.04 which the math works out to be about one hundredth of a
percent or if you extrapolate that out into a ton if you had a ton of molten
wheel weights there's only about three to four ounces of silver in there so
about sixty dollars worth more or less so you're not gonna get rich processing
wheel weights for silver but kind of the bigger picture there is if we use that
lead for a collector metal for some of our smelts we would have to subtract
0.04 grams from our button because that's how much residual silver
was left in our collector metal so that's an important point if you guys
are starting to do some smelting on your own or are trying to do some assaying
especially if you're assaying very very low grades like tailings from your
process or head ore that you're looking for
a little bit of silver a little bit of gold 0.04 grams of precious metals can
make a lot of difference and so you want to make sure you're correcting for that
so I hope you guys enjoyed the video I hope you learned something and saw kind
of a cool chemistry process in action if you have any questions or comments you
can check out our contact information in the description below or you can leave a
comment down in the comment section so thanks again for watching and we'll see
on the next one