Jump to content
BenkeiDNA

Lead sulfate mixed with metallic lead and other metals, any reactions?

Recommended Posts

Hi, i am doing research for a paper about fires and metals and reactions and stuff and would like to ask you guys about lead from USP batterys.

If you had a USP system room with many lead batteries like in this picture, would the total amount of lead still be considered quite small quantities if it leaked out?, and i think it would be very unlikely that most of this lead could get mixed together in a violent fire, so it would create a large steam of molten lead. I was told by a metal exper that he thinks this is true, that it probably would be hard for all the lead to get into a large molten steam that flowed away. He also said this "Also, lead isn’t just present as metal in batteries – it is also a dissolved salt. Therefore, even less metallic lead is present than the total amount of lead in the battery."

Assuming the batteries are charged, there would be lead metal in them. The electrochemical process of lead acid batteries does convert lead sulfate into lead metal at the anode when it is charged. When fully discharged it is lead sulfate and not lead metal – although there probably still is some lead metal under the sulfate layers on the anode. So I suppose it’s possible in a really large fire that the batteries spark/short circuit, the plastic casings melt open, and the metals + acid leak out. Whether or not they all melt/fuse together into a large molten stream of lead is the question, it seems improbable, even with this many batteries in one place. So there should be less metallic lead present assuming these batteries are getting discharged.

So in the fire when the batteries are destroyed and gets discharged, could you estimate from a picture like this with that many batteries in a room what would be a reasonable total amount of metallic lead that would leak out, if it is hard to figure out how much lead sulfate there would be, maybe it is more easy to estimate how much metallic lead there should be?, i am most interested in how much metallic lead there would be.

That being said, lead sulfate is a white powder, but depending upon how sulfuric acid and lead metal interact with one another in a fire, could we maybe see other sulfur compounds being formed which yield yellowish materials forming with other metals involved in the fire?, would any sulfur compounds if they got mixed with the metallic lead make the silver color of the lead change to a more yellow color, and would there be any reactions between lead sulfate, other sulfur compunds, metallic lead and other metals like aluminium and mercury?, i am mostly interested in reactions that could change the silver color of the molten lead and other metals that got mixed.

Img_002.jpg

Share this post


Link to post
Share on other sites

I read "Charged lead-acid batteries have one plate with PbO2 and the other one Pb. Discharged batteries have both plates PbSO4. So neither one is pure lead. The electrolyte is sulfuric acid, more concentrated when the battery is charged." Does this mean that there is no metallic lead at all in USP system batteries when there is a failure in a fire and that only the powder PbSO4. would leak out in the fire, so there would not be any metallic lead at all on the floor in a violent fire if the fire melted the USP systems with the batteris so they discharged?. Could i write in my paper that in a fire, only the powder PbSO4. would pour out on the floor and no metallic lead would pour out at all?.

I also read "About 60% of the weight of an automotive-type lead–acid battery rated around 60 A·h is lead or internal parts made of lead; the balance is electrolyte, separators, and the case. For example, there are approximately 8.7 kg (19 lb) of lead in a typical 14.5-kg (32 lb) battery.".." and ..."The grid structure of the lead acid battery is made from a lead alloy. Pure lead is too soft and would not support itself, so small quantities of other metals are added to get the mechanical strength and improve electrical properties. The most common additives are antimony, calcium, tin and selenium. These batteries are often known as “lead-antimony” and “lead­calcium.”"...

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.