ball milling completed (per)chlorate safely?

[taiwanluthiers]

When I finished making potassium chlorate, I ended up with these largish crystals that needs to be powdered. I was thinking ball mill but the idea makes me nervous. What is the safest way to powder them up?

 

Also how do you dry your finished crystals? I left it on a pan inside to dry and it never did, so I placed it on a baking tray and used a space heater to force dry them...

[AlexPyro66]

I dont know anythink about homemade potassium chlorate but commersial can be ball milled with diferent jar and media for those who are for your bp.You can dry the crystals in the oven at 200F

[bubba153]

I often buy the somewhat coarser and less expensive perchlorate and chlorate and then run them through my mill until they are the mesh size I want. It also allows for the addition of any anti-cake you might want to use. I see no problem with doing this with homemade chlorate. I STRONGLY recommend that you use a dedicated mill jar and media for doing this, and not trying to clean the jar and media that have been used for other things (like BP milling). I would be worried about carrying a possible "incompatible" contaminant into the chlorate, and then possibly having a disaster either in the mill, or in a finished formula that used the possibly contaminated chlorate. Ammonia and sulfur come readily to mind, but there are others as well (heck, most any fuel would be dangerous with chlorate in a mill). I personally use a ceramic-based media for the individual chemicals, and use lead for general mixed milling such as BP.

[taiwanluthiers]

What about steel media, would they be safe with chlorate milling? Currently I use mortar and pestle just because I feel nervous about milling them.

[Mumbles]

If you're not confident enough in your product to mill it, do you really feel confident enough to use it in handmixed flammable compositions?

[pyrojig]

This is where zirc or ceramic Alumina come in handy for clean milling of your oxidizer. Other things like lead or steel will leave a discoloration , but not enough to be of danger. There is not enough fuel value present to present a danger of ignition .

[50AE]

Potassium chlorate is fine to be ballmilled in a hobby ball mill for pyrotechnics. Make sure you apply good discipline in using a separate drum and media for chlorate only.

[Potassiumchlorate]

I ballmill potassium chlorate that I buy, because it is usually caked so hard that it's impossible to sieve away the hard lumps. I never feel uncomfortable with it.

[taiwanluthiers]

I don't know where to get ceramic media without paying through the nose to order it from various suppliers, but steel BB's of the right caliber are available at about 10 cents a piece (naturally if you buy more of them you get a discount). Does adding Aer-o-sil (or other fumed silica) help with caking, or only a little bit? I have brass media for milling bp but I won't use them with anything except for bp or bp components...

[Potassiumchlorate]

I add about 1% silicon dioxide. It helps a bit, though it chunks together a bit again to a certain degree within 3-4 months.

[pyrojig]

Gotta love chlorates . They naturally just cake. As other member have noted, It is best to just rub your chunks through a screen to powder the chlorate .

[WSM]

I use alumina or zirconia milling media, and don't worry a bit about ball-milling single chemicals. Mixtures, on the other hand, I don't mill (except, rarely, BP with brass or 300 series stainless steel milling media; and all this remotely and behind barricades). I never mill chlorate or perchlorate mixtures; it's not if but when it goes wrong !!!

 

WSM

[taiwanluthiers]

I read Passfire's accident analysis article, and there is one instance where someone milled potassium perchlorate in a large 20 gallon container with ceramic media, and it exploded. That's why I asked if it is safe...

 

I really don't know where to get ceramic media locally, no one has heard of it so the only option is to pay through the nose in shipping for them...

Edited December 13, 2012 by taiwanluthiers

[WSM]

I read Passfire's accident analysis article, and there is one instance where someone milled potassium perchlorate in a large 20 gallon container with ceramic media, and it exploded. That's why I asked if it is safe...

I really don't know where to get ceramic media locally, no one has heard of it so the only option is to pay through the nose in shipping for them...

 

If you have a ceramics supplier there (one who sells pottery wheels, clays and chemicals for glazes), they usually have the milling media (for grinding liquid glaze). Other industries use ceramic (alumina or zirconia) milling media, too.

 

WSM

[WSM]

I read Passfire's accident analysis article, and there is one instance where someone milled potassium perchlorate in a large 20 gallon container with ceramic media, and it exploded. That's why I asked if it is safe...

 

Milling potassium perchlorate alone shouldn't be a problem. If it were a mixture or contaminated with organic material, I can see where this is a possibility...

 

WSM

[Mumbles]

I've read that article on passfire too. I've always wondered what really happened there. The reasoning they give is total BS. Potassium Perchlorate cannot ignite in a dust cloud like flour or BP or something. It sounds to me like they had some contamination in there somewhere. Potassium Perchlorate can be set off on it's own, much like potassium chlorate. However, this results in partial detonation, and the force required is orders of magnitude higher than what it would have experienced in that particular ball mill.

 

The answer to all of these inquiries is of course to ball mill remotely. If something happens, you're out a jar and load of chemicals at most. I've said this repeatedly, but you're going to keep ignoring it, but if you can't practice this hobby in a safe location, you shouldn't be doing it at all.