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Subject: Re: Pure Lead out of Old Tire Weights?
From: John De Armond
Date: Fri, 21 Jan 94 20:30:20 GMT (Basse) writes:

>This could get rather messy and/or hazardous but old auto batteries contain
>a lot of lead along with sulfuric acid.  I haven't tried this but cut them 
>open outdoors with lots of running water and thoroughly wash away the acid
>remove the plates and melt them.  There will be lead sulfate present too but 
>this will probably float as a solid on the surface of the molten lead and can 
>be skimmed off.  Be sure and wear face protection when doing this and old 
>clothing because it will likely be splashed by acid during this operation.
>Rubber or other acid proof gloves are also advisable.  If you decide to do
>this be CAREFUL!!!  I'm not responsible for accidents or injury but the lead
>should be fairly pure.

It works better just to smelt 'em in place.  Smelting reduces the lead
sulfate to lead so the recovery is much better.  Here's how I used to
do it (and may still :-)

With a small pickax or similar implement, poke holes in each cell of
the battery.  Stash it someone convenient like a ditch to drain.
The acid is corrosive but typically not terribly strong in heavily
sulfated batteries typical of dead ones.

Using firebrick, build a square box about 18" to the side and about
a foot tall.  Leave a small door on one side through which air can
be blown.  Fill this box with charcoal.  Sit a battery atop the pile.
Build a firebrick chimney around the battery so that an inch or so of charcoal
can be stacked on all sides of the battery.  Fairly heavily dust the
battery with slaked lime.  Stack another couple of inches of charcoal on
top of the battery.  Then repeat this process until you have 4 or 5
batteries stacked up.  Ignite the charcoal in the bottom with fluid or
whatever and apply a strong draft of air to the opening.  Ignite the
charcoal in several places around the batteries with a propane
torch stuck through the bricks.

The reducing agent is carbon monoxide which is produced as the charcoal
burns incompletely.  The pale blue flame that burns from the top
of this stack is the excess CO.  You want the fire to be fairly hot
in order to activate the reducing reaction but you also want it 
to burn oxygen starved to produce lots of CO.  The very hot fire in
the bottom provides the heat and the charcoal around and atop the 
batteries provides the reducing environment.  Lime is the flux.

When you have this thing cooking right there will be a pale yellow,
partially opaque, very choking smoke emerging from the top of the
furnace.  These are the various oxides of sulfur.  It will burn the 
lungs and defoliate trees.  Stay upwind.  Sure it's environmentally 
politically incorrect so if it bothers you, don't do it.

When this thing burns out and you unstack the firebricks you will find
a nice solid pool of lead and a bunch of scuzz.  The scuzz is moderately
toxic because it contains the residual lead sulfates and oxides.  Either
bury or bag it for disposal and wear a respirator (NOT a dustmask).
The lead will contain some cadmium and maybe some calcium if from 
maintenance-free batteries but that can be scavenged as previously
mentioned.  The lead recovery rate from this process is very high,
much higher than merely melting the plates.


Newsgroups: rec.crafts.metalworking
Subject: Re: Pure Lead out of Old Tire Weights?
From: John De Armond
Date: Sun, 23 Jan 94 05:41:28 GMT

<MJE100G@ODUVM.BITNET> writes:

>     Smelting Whole Batteries-  Hmm let's see how many potential problems
>with this approach.
>           1) Draining acid into groundwater

Why do you environuts always assume that anything that hits the surface
of the ground instantly pops through 60 ft (in my area) to reach
the groundwater?  And have you ever noticed that when you pour acid
on the ground it bubbles?  That's a neutralization reaction with the 
limestone and other goodies in the soil.  Voila!  No acid.

>           2) Lot's of nasty sulfur fumes

yep.  Smells Goooood.

>           3) Most probably lots and lots of lead fumes

Unless you can trace the synthesys of some sort of organolead (think we
could make tetraethyl lead) compounds, nope.  There may be some lead
oxide aerosol.  THAT is why you don't sniff the chimney.

>      I'm all for DIY projects, but this just sounds like a REAL bad idea.  I
>would put this past being politcally incorrect.  I feel this would be very
>environmentally unsound, pretty dangerous without the right sort of protective
>gear and almost definitely illegal (both water and air pollution) in most
>places.  Remember, old batteries are categorized as hazardous wastes for
>good reasons.

So's motor oil.  Nothing said this crap has to make sense.

>I hate to flame anyones response, but this just seems to be a bad idea.

Then don't do it.  But it sure works for me.


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