lead analyzed

[Lefty bullseye shooter]

So I found a scrap metal dealer real close to one of the ranges I belong to about 50 min from home that was willing to use their XRF analyzer on my lead. I had three leads that I wanted to get analyzed and these are the results:

1. Lead from an indoor range that only allows lead bullets (I added tin)
Si 1.950%
P 1.191%
Cu .127%
Sn 1.902%
Sb 2.546%
Pb 92.28%

2. Lead from the indoor range close by that allows jacketed bullets
Fe .056%
Cu .328%
Sn .314%
Sb 1.134%
Pb 98.17%

3. 38 pounds of mystery lead that a friend had and he was tired of moving it around his garage
Si 1.713%
P 1.078%
Cu .280%
Sn 8.224%
Sb 3.541%
Pb 85.12%

Lead # 1 seems like where I want to be. I'm loading low velocity 45acp and am gonna start casting for 32acp. With the help of the very nice lead alloy mixing spreadsheet I can mix #2 and #3 to get to where I want to be. The guy at the scrap yard was very nice and willing to help. He told me to mix some more up and bring it in and he would analyze it! I know for sure I found a new place to bring my scrap aluminum. And since I was so close to the range I loaded up the gun box and shot my new Pardini SP Bullseye pistol. Win win trip for me.

So my question is what is Si and P doing in there. I know I'm new to this but have never heard of these in lead before. Did I not flux enough? I alternated between sawdust and wax three times each before I poured into ingots and used wax to reduce while I was making ingots again to keep the tin in the alloy.

Scott

[bangerjim]

Cast it and shoot it!

8% Sn is high if you trying to save $$ on tin.

Cu just adds a bit of "toughness" (NOT hardness) and is desirable.

The other stuff.......who knows? Error in the gun?

never seen that stuff in Pb B4.

banger-j

[Bullwolf]

I've heard that sometimes rusty lead ingots will register a higher than usual Fe (Iron) reading, so I tend to discount Iron readings if I see much of it in a lead alloy.

Si= Silicon

Silicon makes up 25.7% of the earth's crust by weight, and is the second most abundant element, exceeded only by oxygen. It is found largely as silicon oxides such as sand (silica), quartz, rock crystal, amethyst, agate, flint, jasper and opal. Silicon is found also in minerals such as asbestos, feldspar, clay and mica.

Sand in lead = Si reading on a gun, cleaned fluxed lead would likely reduce or eliminate this sort of a reading.


P= Phosphorus

Phosphorus is a component of bones, and teeth, and many other compounds. Phosphorus is never found as the free element but is widely distributed in many minerals. Phosphate rock, (apatite, impure calcium phosphate), is an important source of the element.

Again like sand, phosphorus may be a reading from a pulverized rock dust. Ive often wondered what the fine black powdered range dust would scan like.

I'd expect that clean fluxed lead would show less or no Si, or P.., assuming that they aren't just errors in the reading in the first place. I expect they are exactly the type of thing that you skim out with the burnt carbon sawdust, when fluxing lead to make ingots with.


As high as the Sn (Tin) content was in that lead you got in sample #3... You really should thank your friend for giving it to you.

If it was me, I would try to thin the Tin out some in that alloy by diluting it with either pure lead, or antimonal lead, until it got down to around 2% tin for a good casting alloy. Or you could just be lazy and likely cast with it just fine, while wasting the expensive extra tin. The copper at those low concentrations doesn't hurt anything, and only serves to make the alloy tougher.


Thanks for the numbers, it's always nice to see what you are really working with.



- Bullwolf

[BattleRife]

No way I believe that phosphorous number. Phosphorous is considered an impurity in almost every metal and is usually kept low, like 0.04% max.

The silicon reading is also highly suspect.

[MBTcustom]

First of all, cut the numbers down to 1 decimal place. Most XRF guns have much more resolution than they have accuracy. If the gun was dirty, or if the ingots were dirty, you're liable to get any kind of strange reading on that alloy. The XRF machine I have access to is in a laboratory environment, and I prep all the samples carfully and it still throws some janky numbers out there. For a while there, it was putting a value of gold in almost every sample I ran through it (some of the solder actually did have some gold in it, but COWW???? Not a snowballs chance in hell)
Even now, I take 5 samples from different parts on the ingot and average them to get sortof real numbers.
Antimony is much more visible and reliable than tin is for some reason.
Any element that comes in less than .5%, I don't trust unless it pops 4 out of 5 times on the test sample.

Bottom line, I would trust the Sb numbers on those samples.
Throw the weird elements in the garbage because there's no way in heck.
Take the Sn values with a grain of salt. It's probably at least +- .5 grains of the value shown. Sample 2 probably has no tin at all. Sample 1 is probably pretty close to being right on the tin.
I took a close look at the three test results and comparring to the periodic table, I would throw out everything but the lead tin and antimony as machine error. I would believe the Cu if it were greater, but at those low numbers coupled with the bogus phosphorous and iron readings I don't think it's real.
Good to know what you have!
Now go mark your ingots so you don't get them mixed up! (ask me how I know. LOL!)

[Lefty bullseye shooter]

All
Thanks for the reply's. I was wondering if I should trust the numbers at all but it sounds like I can trust most of them. #1 was lead only range lead that I tried to add 2% tin to it by weight. According to the gun I got pretty close. #2 was lead from our league range so there is a lot of 22 lead and jacketed bullets so I wasn't expecting much tin. The last #3 sure seemed hard when I cut it to expose a fresh edge. I guess I'll use the numbers and mix accordingly and see what happens. It's better than not having any info.

Scott

[mold maker]

Exact % even though measured with expensive equipment, is like exact BHN. It should be recognised as just a little better than a SWAG estimate. Obsessing over it can cause loss of hair and sanity.
Just saying.