Bismuth Grinding Media

[BlueComet24]

I would like to replace the lead media I currently use in my ball mill with something less toxic. I've considered ceramic media, such as Cole-Parmer 1/2" burundum, but I'm not fully clear on whether or not it's safe to use for milling BP. One option that I've considered is using bismuth, as it is nearly as dense as lead, soft (and supposedly nonsparking, although I'd like more confirmation), and has low toxicity. However, bismuth is expensive at around $50 for the 5 lbs I think I'd need for my Lortone 3A, and I don't know that anyone's actually tried it in a ball mill. Bismuth has no incompatibilities that I know of, but I would certainly like the input of someone who is more familiar with it than I am.

Any advice you have to give is appreciated.

-Blue

[schroedinger]

Actually the lead you are using is metallic and not salt form, so it is not very harmfull, as you always wear a respiratkr there is nothing to really wonder about.

 

Media that is proven to be work is:

The king of ceramic media: Yttrium stabilized zirconia media

High Al2O3 content ceramic media.

A couple grades grades of non spark stainless steel media.

Brass

Lead filled copper/brass tubes.

 

For the ones you can't make at home i cant help you on where to get it, specially the right grades. I'm just not US based.

[Fulmen]

Interesting idea, although I fail to see the real hazard with lead. You're not eating your BP, are you?

 

One thing is the brittle nature of Bi, for shotgun shots it's usually alloyed with 3% tin. Still somewhat brittle though (compared to lead shot), but probably good enough for milling.

[Nessalco]

I use a mix of 1/2" and 3/4" brass rod stock, cut into pieces. Works like a charm, and wears very, very little. I've been using the same media for 5 years and have no need to replace it any time soon.

 

Kevin

[BlueComet24]

Thank you all for your advice.

 

Actually the lead you are using is metallic and not salt form, so it is not very harmfull, as you always wear a respiratkr there is nothing to really wonder about.

Good point about the state of the lead. I realize that metallic lead is not nearly as hazardous as lead oxide, for example.

 

Interesting idea, although I fail to see the real hazard with lead. You're not eating your BP, are you?

Haha, no I don't eat it. I always wear a dust mask when I make BP dust and I wash my hands after handling BP. I'd rather be safe than sorry with a neurotoxin.

[Fulmen]

While lead definitely isn't good for you it's not that bad. I've been a shooter all my life, breathing the smoke on poorly ventilated ranges and casting bullets. I've learned to be careful, to clean my nose and wash my hands after shooting and to use a mask or proper ventilation when casting. As long as you're reasonably diligent in hygiene and safety I don't think the lead will pose any hazard. At least not when compared to the risks of a stray spark in our line of work.

[BlueComet24]

I've got a pellet rifle that I sometimes fire lead pellets with. I've switched to PBA for pest control, mostly so that if a scavenger eats something I can't retrieve, it won't get poisoned. With firearms, I think the real lead poisoning issue is from the decomposition products of lead styphnate in the primers. As far as casting lead, it boils at a far higher temperature than its melting point, so you should be fine with good ventilation.

Sparks are acutely dangerous to pyros, but most other people are "immune".

[gregh]

While lead definitely isn't good for you it's not that bad. I've been a shooter all my life, breathing the smoke on poorly ventilated ranges and casting bullets. I've learned to be careful, to clean my nose and wash my hands after shooting and to use a mask or proper ventilation when casting. As long as you're reasonably diligent in hygiene and safety I don't think the lead will pose any hazard. At least not when compared to the risks of a stray spark in our line of work.

I guess it depends on the velocity of the lead as to how bad it is for you...

[schroedinger]

No, the contaminitation of comps with lead, depends more the wear of the media and that depends mainly on how you chargd your mill.

[MrB]

Interesting idea, although I fail to see the real hazard with lead. You're not eating your BP, are you?

 

Even if you were, it wouldn't hurt you.

 

I guess it depends on the velocity of the lead as to how bad it is for you...

 

Yes... yes i can see how impact energy would translate to lead poisoning.

 

More ontopic:

Bismuth being brittle rather then soft might be an issue as well.

B!

[Fulmen]

I've got a pellet rifle that I sometimes fire lead pellets with. I've switched to PBA for pest control, mostly so that if a scavenger eats something I can't retrieve, it won't get poisoned.

It will take a lot more than a few pellets to poison a critter. The biggest problem is with birds, they eat small pebbles to fill their gizzard, if they ingest lead pellets the grinding action will release large amounts of lead.Once in the food chain it will accumulate in predators much more efficiently than by them eating a few pellets themselves. Not saying lead-free pellets are a bad idea, it's never wrong to limit the amount of lead we dump into the environment. But if all you do is shoot some pests with an air rifle you really don't have any reason for feeling guilty.

 

 

With firearms, I think the real lead poisoning issue is from the decomposition products of lead styphnate in the primers. As far as casting lead, it boils at a far higher temperature than its melting point, so you should be fine with good ventilation.

Even with the difference in boiling point there is little doubt that casting lead will mean exposure. Have you ever tried casting without proper ventilation? The taste in your mouth is pretty conclusive. Same goes for lead bullets, The combustion temperature can be well above the boiling point, and you only need to shoot a few rounds without proper ventilation to taste the difference. Firing lead bullets through a suppressor shows the same thing, the fouling contains significant amounts of lead that you don't see with jacketed bullets.

[dynomike1]

What about zinc? Most canon shooters use them and zinc isn't hard to come by. I think when i was casting lead cannon balls 600 deg. F. was the ideal temp. I found a deal on pool balls so i haven't casted any in a long time.

[FloridaCracker]

What do cannon shooters use zinc for? I'm a bit confused with most of that post if you don't mind clarifying.

[BlueComet24]

Sounds like he used to cast cannonballs out of zinc.

[Fulmen]

As I understand it zinc is used to replicate the weight of cast iron balls, they can also be reusable if fired into s soft backstop. I don't see any reasons why zinc shouldn't work in a mill, but without any real experience it's an educated guess at best.

[dynomike1]

Well i guess my brain out ran my fingers. Fulmen is right. I think Zinc is cheaper than lead, it melts at. 787.1deg. F..

[BlueComet24]

Brass is usually somewhat expensive, but might it work and be economical to melt down brass casings along with pennies and additional copper? I believe that US pennies minted after 1982 are 95% zinc and 5% copper, but you want at least 50% copper in soft brass. One dollar's worth of pennies would be 44.18ml and 250g. Add 225g of copper and you'd have almost a pound (450g) of 50/50 brass.

[dynomike1]

Or you could go to the scrapyard and get some old alternator casings or carburetors.