10 replies to this topic

[martgold]

Hi

I'm looking for recommendations on the best type of jar for ball milling. On all the various pyro sites, milling media and ball mill design have been discussed in great depth but very little on the jars used (with safety in mind). I'm surprised that there are not more ball mill accidents considering the jars used for ball milling as posted on YouTube. Glass and steel cans used with marbles etc.

Any thoughts would be greatly appreciated.

[rocketpro]

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Edited by rocketpro, 06 August 2010 - 09:37 AM.

[Mumbles]

If I had to pick a "safest" mill jar, I'd go with the rubber lortone style jars. It seems to really prevent clumping due to the slight give. Any sort of caking, easily knocks out with a light rap with a rubber mallet. I'm learning this the hardway with my new PVC jar. I get BP that is hard as a rock on the walls. They also really reduce the sound. I feel there is less risk in the case of explosion. Just like HDPE, the give in the jar will drastically reduce shrapnel and energy left in the fragments once they tear. A quick note on the rubber barrels. The bigger ones are octagonal, which acts like 8 lift bars. For optimal efficiency, you have to run the jars at a much slower speed than a similar sized cylindrical jar.

I do agree there are some very dumb things on youtube.

[Vic]

4"water pipe with push on ends works very well.

I would go along with push fit on one end. I'm sure there have been tests but I can't remember where, showing a screw top ballmill exploding, compared to a push fit bung there was a considerable amount of shrapnel from contained jar where as the push fit type the end cap just blew off.

[martgold]

If I had to pick a "safest" mill jar, I'd go with the rubber lortone style jars. It seems to really prevent clumping due to the slight give. Any sort of caking, easily knocks out with a light rap with a rubber mallet. I'm learning this the hardway with my new PVC jar. I get BP that is hard as a rock on the walls. They also really reduce the sound. I feel there is less risk in the case of explosion. Just like HDPE, the give in the jar will drastically reduce shrapnel and energy left in the fragments once they tear. A quick note on the rubber barrels. The bigger ones are octagonal, which acts like 8 lift bars. For optimal efficiency, you have to run the jars at a much slower speed than a similar sized cylindrical jar.

I do agree there are some very dumb things on youtube.

What a speedy response. Thanks for all your input.

I quite agree with fflach that a screw top jar would be worse and is potentially a bomb waiting to happen but I wouldn’t want to be any where near an exploding PVC jar, even with a small amount of BP in it due to the potential shrapnel.

I like the idea of a push fit end cap but I can’t find anything to fit HDPE pipe. Also the problem with HDPE is the lead balls would slide and not tumble.

The other thought I had was to use something like the rubber hexagonal tumbler AR12 under the brand Thumler’s Tumbler which is rated at 12lb capacity.My link I like the setup with this particular jar though it is too big for what I want. I only want to work in small quantities due to my setup.

Working on the principle that the most dangerous time in ball milling is when it is finished and the jar has to be emptied.

This jar would suit being fitted into a heavy wall HDPE pipe and undone with relative safety, in case of accidental ignition. What do you think? Is this logical? Avoiding putting your head over the mortar tube so to speak.

Reading on various forums that commercial charcoal and KNO3 is often contaminated with grit, metal etc then there has to be a very real increase in risk of ignition whilst grinding AND therefore at the time of opening the container, unless you produce your own charcoal from known wood source without shot embedded in it, stones grit etc. and also re-crystallising your KNO3 unless it’s lab grade.

I have a recollection that PGI filmed a test, a number of years ago, for a ball mill explosion and the milling media didn’t travel far. Does anyone remember this?

Hi Mumbles, I see you like the idea of rubber barrels too. Can you point me in the direction for one of the octagonal barrels, in the UK, as the one above is very pricey to get it shipped from the US and ideally I would prefer a smaller one.

Decisions, decisions. What to do. Cheers again.

[dr thrust]

manchester minerals have the jars for you , ebay to, job done.
round barrelas are fine, its all about jar speed and how much media you use , read this

Edited by chris m, 14 June 2010 - 10:27 PM.

[rocketpro]

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Edited by rocketpro, 06 August 2010 - 09:37 AM.

[Arthur Brown]

All the plastic tubes are waste pipe! but actually doing the cutting nicely is best done by machine. The plastic end caps supplied with a rock tumbler are much easier and lighter than getting plumbers endstops.

[dr thrust]

Cheaper at the builders merchants though. The brown tube is waste pipe.

lol if you dont mind buying 4 meters at a time

[Guido Fawkes]

No ones mentioned the jars supplied by Inoxia these start at 1.3 litres and go up. they are soft plastic so flex and dont clog they have a screw cap and a seal but even in the event of an accident I should imagine the burst pressure would be way shy of 100psi. my only reservation may be longevity but my first ones done 20 hours with absolutely no sign off wear and at under a fiver am I missing something?

[martyn]

No ones mentioned the jars supplied by Inoxia these start at 1.3 litres and go up. they are soft plastic so flex and dont clog they have a screw cap and a seal but even in the event of an accident I should imagine the burst pressure would be way shy of 100psi. my only reservation may be longevity but my first ones done 20 hours with absolutely no sign off wear and at under a fiver am I missing something?

You might be right to be concerned about the durability. I bought a few and one split at the shoulder on the first use, spilling its contents, fortunately without incident. I use the usual 50% vol of lead media - they might be more durable with ceramic. They might also be more durable if used in conjunction with the rubber strips available.
This is not in any way meant to 'diss' (as my kids say) Steve. I have been 101% happy with everything else from Innoxia. I didn't ask for a replacement as I lost confidence in the jar, I only bought a few and the others found use as storage jars, as you say, they are cheap enough.