Ball Mill Exploded

[avidus]

Hi There,

Today my ball mill exploded,

 

I have used alumina balls 40mm, 30 Liters plastic jar and total 3Kg ( potassium chlorate, sugar, iron oxide, aluminium mix for an ignition charge )

 

During explosion ball mill runs around 300rpm and already run for 30mins.

 

Luckily nobody injured or killed. But mill heavily damaged.

 

I'm still not sure what's the cause of the explosion.

 

Do you have any idea?

[MadMat]

The reason your ball mill exploded is pretty simple; potassium chlorate and aluminium should not be ball milled together. If your going to say; "I done it many times before without a problem." just consider that your were lucky those times before. Potassium chlorate shouldn't be ball milled with any fuels, metals in particular.

Edited May 14, 2016 by MadMat

[stix]

If it's true that your ball mill exploded and you don't know why - then DON'T use one until you truly understand.

[macs]

Potassium Chlorate and Aluminum? Never ball mill a mixture like this. 3kg! Wow! You are very lucky! If you are not sure why it was a bad idea to ball mill this stuff, you need to take a step back and re-learn the basics. Stay safe.

[dagabu]

Hi There,

Today my ball mill exploded,

 

I have used alumina balls 40mm, 30 Liters plastic jar and total 3Kg ( potassium chlorate, sugar, iron oxide, aluminium mix for an ignition charge )

 

During explosion ball mill runs around 300rpm and already run for 30mins.

 

Luckily nobody injured or killed. But mill heavily damaged.

 

I'm still not sure what's the cause of the explosion.

 

Do you have any idea?

 

You were essentially making a kind of flash in a way and the impacts of the extremely hard media (alumina) probably pinched the comp with enough force to ignite it.

 

Black powder is the most dangerous comp you should ever even consider ball milling and I am afraid to say this out loud but ball milling potassium chlorate, sugar, iron oxide, aluminium is just freaking STUPID!

 

Don't mill this in a mortar-pistle or mechanically, diaper mix ONLY!

[avidus]

is perchlorate safe to mill? Actually I tried potassium nitrate before but burnrate is very low. I never tried perchlorate.

[Arthur]

BP is the only mixture that need ever be milled. Beyond that,it's only single material ingredients that get milled.

[dagabu]

is perchlorate safe to mill? Actually I tried potassium nitrate before but burnrate is very low. I never tried perchlorate.

 

NO! Potassium nitrate is the only oxidizer you should mill and NEVER with a finely divided metal.

[avidus]

Ok, I'll remove the aluminium from the equation.

 

Try to solve burnrate problem with Nitrate.

 

What about balls? Do you suggest to use lead balls? Or alumina will be ok?

[PhoenixRising]

Can you please direct us to the link that showed you how to use a ball mill?

Edited May 14, 2016 by PhoenixRising

[avidus]

I'm very upset,

please only serious answers.

[memo]

you have good reason to be upset, you are also very lucky. when lloyd read this he will be able to answer any questions on ball milling. in fact he wrote the book

[avidus]

very lucky, indeed.

[PhoenixRising]

I'm very upset,

please only serious answers.

 

 

I'm just curious as to what sources you used before. I'm just asking for a link to the information you acquired to know that ball mills are even used in pyrotechnics. This is serious, because you nearly lost your life to misinformation. It's very serious indeed.

[avidus]

I dont have any link, using ball mills for around 2 years. Most of them DIY, but that one industrial. Actually previous mixtures was ratherly safe. But that mixures maybe run for around 100 times.

[dagabu]

I'm very upset,

please only serious answers.

 

You know, you can still make an ignition charge but just mill the ingredients separately if they have to be milled or just diaper mix the ingredients. Yes, you are upset and you are fortunate as well. I spent a full month in a coma after a BP accident three years ago and had extensive skin grafts. This was just a fire, you has explosives* in a ball mill jar. You need to find a completely different method that removes the risk as much as possible.

[Arthur]

Ball mills -my opinion!

 

Mill separate ingredients, use a separate mill for chlorates,

get all the ingredients to the right size separately for each project.

 

BP is the ONLY compound that can be milled with some safety.

 

Mill Kitty Litter between other ingredients to clean the media, use the milled product for plugging tubes and rocket nozzles.

 

A mill is not "safe" but can be made safer by careful methods. Remember, kill yourself and the coroner says suicide, kill anyone else and now you are a terrorist,

Edited May 14, 2016 by Arthur

[mikeee]

Most fuel comps should be milled separately, and then screened together.

Some fuels can be combined using a wet mix process and then dried.

There are some reliable tutorials that show how to mix various fuel comps.

YouTube is not a very reliable source to depend on for proper methods.

You need to consider who produces a video or tutorial before considering it a safe method.

You want someone with many years of experience not some Newbie posting a video on YouTube.

[lloyd]

OK... serious answer:

 

A 30L vessel (assuming 'ordinary' length-to-diameter features) would be about 370mm in diameter.

 

Regardless of the media diameter (stated to be 40mm), at 300rpm, EVERYTHING in the vessel including material AND media would be centrifuged HARD TO THE WALLS. There would be ZERO milling action going on during the run.

 

The only time media would impact would be during the (perhaps) one revolution during which the contents "came up to speed".

 

But you said it had been running 30 minutes; so that time is long past.

 

There's no way your milling conditions could have caused the explosion REGARDLESS of the dangerous nature of your contents.

 

Perhaps you had some other ingredient in there that caused the contents to auto-combust. The milling conditions YOU stated could not have cause it except during startup or stopping of the mill.

 

You'd have been in much more danger if you'd had a mill rotating at a realistic speed.

 

I vote: "Joke on the public". He was pulling our legs, trying to get someone to notice that the mill was turning more than 4X faster than critical speed.

 

LLoyd

[MadMat]

Heh, I never noticed the spec.s on the mill. The second I saw what was being combined, the red lights went off in my head.

Edited May 14, 2016 by MadMat

[memo]

i missed the 300 rpm myself

[alexpyro101]

Ok, I'll remove the aluminium from the equation.

 

Try to solve burnrate problem with Nitrate.

 

What about balls? Do you suggest to use lead balls? Or alumina will be ok?

jesus christ, no you remove EVERYTHING from the equation. You mill single chemicals, or blackpowder (with its own jar and media) only.

[lloyd]

Alex,

You didn't read the post. What he claims happened cannot have happened as he states it -- not even with straight chlorate flash powder!

 

LLoyd

[MadMat]

O.K. I guess most of us got schooled for lack of critical reading...

[avidus]

if anyone wonder, what it look like exploded mill.