Extracting lead from car batteries?

I have a couple of battered old car batteries. There is no local scrap dealer that will take them so I was wondering if it would be possible to extract the lead myself and sell it for scrap. I have searched on google and cannot find anything about this and I suspect it would be dangerous and impractical. However I thought there's no harm in asking here. I was imagining that I could open the battery up and pour the acid into some kind of strong alkali, neutralising it to make it safe for disposal. But then, I certainly wouldn't like to try this without some advice first.

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GeorgeS2841 month ago

Dilute the dickens out of that battery acid with water; adding an alkali to battery acid will make it "explode", scattering toxic, burning material everywhere. I watched a chem student try to neutralize a spilled beaker of sulfuric acid with sodium hydroxide, ducking behind a lab bench as I screamed "NO!" Had it not been for an alert grad student to pull her under the lab shower, she would have been scarred for life. The reaction was violent and instantaneous. Mix the water in slowly - old acid can be very concentrated, and the heat of hydration can boil the solution. Once well diluted, neutralize slowly with a well-diluted alkali solution, and dispose of the precipitated salts properly. Save your eyes.

Never, ever add water to a concentrated acid!!
You mention the sodium hydroxide reaction - it only tells me the person doing it was brainless and used a concentrated mix.
With your suggestion of adding water the water can boil into steam instantly - something you don't want....
The only half-way safe way I can recommend is to use a battery hygrometer or similar to remove the acid from the battery and then to add the acid to some really cold water and doing this slowly.
In any case I would not even attempt to get lead from old batteries as far too many toxins are involved, not to mention the hazards for the enviroment.

Yes - she, a freshman Chem student, just reacted without thinking at all; she had spilled 4M lab acid out of a glass reagent bottle by knocking it over. And grabbed a bottle of 4M Sodium Hydroxide to neutralize it. Do the math, and you'll know what the explosion was. I was about 12 feet away, knew what was in the bottles, knew what was about to happen when I saw her tip the NaOH, and ducked; the sound was like an arcing short in a high voltage line. Unforgettable.

But this is battery acid - not concentrated sulfuric. People add water to batteries all the time - but you still do it slowly, as I suggested, to minimize total heat of hydration release and spatter. That said, if you were diluting concentrated Sulfuric - or any other strong acid - you absolutely would add the acid to the water, not vice versa.

Incidentally, I'm talking about IF the acid is still in the battery, and you're filling it through the caps. In an open container, proper practice always dictates that the acid be added to the diluent water. You only get one set of eyes.
Toga_Dan29 days ago

Take old batteries to a car parts place. They'll give you a receipt which is good for deferring cost of a new battery.

Toga_Dan29 days ago

Googled cost of lead.

About 10 cents a pound.

3 batteries might net u 10 bucks.

NachoMahma6 years ago
.  It is very difficult to handle lead in a safe manner, especially if you plan on melting the lead. If you melt it, you have lead fumes to worry about (plus fuel costs). If you don't melt it, you still have gloves and other protective clothing to dispose of.
.  The sludge (lead sulfide/sulfate/sulf?) may be difficult to process into elemental Pb without creating pollutants and/or using a lot of energy.
.  For small amounts, it just isn't worth the risk. Looks like scrap Pb is selling for about 0.50 USD/lb (but I didn't look very closely).

Egads, is that my problem ?   When I was younger, I not only played with raw mercury,  but made a whole bucket load of sinkers out of a large lead brick......*sigh* 

I used to sell lead by the pound, as flashing for roofs and windows.  We used to unroll the lead sheet with bare hands, cut it with a knife, and roll it up again.

The metal is mostly dangerous if formed into pellets and fired at high velocity.

To process the sludge, I'd dry it, then heat it in air (say, in a clay plant-pot in the coals of a barbecue) to turn the sulphides into oxides, then stir in some powdered unburned charcoal, add a lid and heat again.

If you've remembered to put a collecting vessel under the hole in the plant-pot, you'll collect molten metallic lead.

OK, it's a bit smelly when you roast off the sulphides, but just do it outdoors.

lukemarq Kiteman8 months ago

That is excellent info not easily found! Thank you.

Modern batteries have very thin plates that sulfate all the way through. With this info I can turn old batteries into new home made ones (that will live longer).

back in my teens, when I melted the lead for sinkers,  I did it in the basement ....*sigh*
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