Sciencemadness Discussion Board

Identifying lead compositions?

Darth-Vang - 1-8-2022 at 11:31

Is there way to identify lead compositions other than using a hardness tester? I want to know what’s in my lead. Curious to see if there’s a way to tell how much lead is in the “unknown” contents of my lead ingots.

CharlieA - 1-8-2022 at 14:07

Maybe you could search for the quantitative analysis of solid lead/lead alloy samples. Unless you have access to high-powered analytical instrumentation, you might try looking in older quantitative inorganic analysis texts.

Also, I would guess that there are standard tests recommended by the ASTM
(American Standards for Testing Materials?).

If you suspect certain metals are present in your specimen, perhaps you could identify them with spot tests. I think the more specific the spot test is, the more complicated the necessary reagent is (usually an organic compound).

Just a few ideas off of the top of my (bald) head.:)

j_sum1 - 1-8-2022 at 17:32

There is an awful lot that will dissolve in lead. And all will have the effect of making the alloy harder even at low concentrations. For this reason, a physical test is not going to tell you much.

If you are doing a chemical test and do not have modern analytical gear, (who does?) then the first step is to narrow down the possibilities of what you believe might be in there. Then look for qualitative tests for those elements. Good luck. This is not likely to be easy.

For starters, lead ores generally have a lot of other metals from neighbouring elements: tin, antimony, bismuth in particular. Unless these are deliberately removed in a refining process, they will still be present to some extent. But there is a truckload of other possibilities as well. What is the source of your lead?

Darth-Vang - 7-9-2022 at 18:10

Quote: Originally posted by j_sum1  
There is an awful lot that will dissolve in lead. And all will have the effect of making the alloy harder even at low concentrations. For this reason, a physical test is not going to tell you much.

If you are doing a chemical test and do not have modern analytical gear, (who does?) then the first step is to narrow down the possibilities of what you believe might be in there. Then look for qualitative tests for those elements. Good luck. This is not likely to be easy.

For starters, lead ores generally have a lot of other metals from neighbouring elements: tin, antimony, bismuth in particular. Unless these are deliberately removed in a refining process, they will still be present to some extent. But there is a truckload of other possibilities as well. What is the source of your lead?
Lead is supposedly pure lead, possibly has tin or antimony in there, but I swage bullets with it with no problem.(swaging dies can only use pure lead or close to it)