20 replies to this topic

[GreenGenie]

1) ***I have bowed to the inevitable and bought a ball mill. A CR2 from Manchester Minerals (recommended to me by one of the societies sages Arthur Brown) with large rubber barrels. I wanted to start off with something simple and safe, so I put some KNO3 in and milled that overnight. The KNO3 is granular I wanted to turn it into a powder. The ball mill has done this; but the KNO3 is now a pale grey.

Does this matter? I hear a lot of talk about the importance of purity. This stuff is now clearly impure. Presumably material either from the lead balls or from the rubber drum has been transferred to the KNO3.

I bought the lead balls from cooperman; so they should be fine. I was surprised that the lead balls were shiny when they arrived. Now they has been used they are no longer shiny. Presumably they were coated with something which is now in the KNO3.

2)*** I bought the ball mill principally for making BP and turning lumpwood charcoal into powder. However, I would like to make some simple candy propellant and I dont fancy cooking it (sounds a little risky). I have previously made it by diapering KNO3 & icing sugar. Is it safe to ball mill the KNO3 & sugar?

[Arthur Brown]

Purity usually doesn't matter with BP. Let's face it BP was a real life product in the days before "AnalaR" and other indicators of purity!
With Nitrate most products over 95% will be fine. Sulphur whatever you can get will work, Charcoal really does need to be the correct wood but well made willow charcoal will work fine.

[dr thrust]

the discoloration will be from the lead, ive used lead media for twelve months now and it doesn't seem to effect performance, you can switch to brass media but you'll need deep pockets, as for milling the kno3 and sugar i think you could get a sticky mess!, your best bet would be to get a cheap coffee grinder off ebay and grind up the sugar in that, ive got three of them one for fuels, oxidizers, and one for potassium benzoate( really painful to mill)

[cooperman435]

GreenGenie

the lead was shiny as it was brand new, as in moulded 2 days earlier by my own hand. It does take a while for it to discolour on its own.

the discolouration is lead yes but dont forget that kn03 is a hard salt so will pick up some lead whereas charcoal and sulphur are softer so protect the lead more.

[fruitfulsteve]

As it happens i have been ball milling kno3 today, and because i had a fairly large amount to do i decided to do a bit of a study using ceramic balls and chrome plated steel balls in differant ball mills and jars, i concluded that the quickest was to use the steel media in a finned barrel, this got 250g of kno3 down to -200 mesh in 3hrs having said that the ceramic wasn't far behind in the finned barrel but both we're somewhat slower in the non finned barrel. Also the steel media has slightly contaminated the kno3 with the very small amout of rust on the balls. For chlorates i have ceramic media and a barrel that i only use for baclo3 and kclo3(feclo3 can be a bit unstable i've heard ). So if you want to keep your chemicals pure use ceramic balls!!
ffs

[knackers]

However, I would like to make some simple candy propellant and I dont fancy cooking it (sounds a little risky). I have previously made it by diapering KNO3 & icing sugar. Is it safe to ball mill the KNO3 & sugar?

hey G'G, i don't see any risk in cooking R-candy on an electric hot plate, kn03, sugar, glucose,water and a catalyst, ( Fe203),

i've personaly made a bit of it and know a few people that have made plenty of it with no trouble what so ever, also" the difference of just milling and mixing , opposed to doing it correctly , ( heating it altogether in a non stick frypan ) is tremendously so that if you are not going to heat the ingredients together , honestly " its not worth doing "

as far as your contamination, it may cost abit more but " pyrotechnics as a hobby is not cheap" i swear by stainless steel balls.
great milling times, no contamination what so ever and as safe as houses, i use 5/8" ss.

[fruitfulsteve]

hey G'G, i don't see any risk in cooking R-candy on an electric hot plate, kn03, sugar, glucose,water and a catalyst, ( Fe203),

i've personaly made a bit of it and know a few people that have made plenty of it with no trouble what so ever, also" the difference of just milling and mixing , opposed to doing it correctly , ( heating it altogether in a non stick frypan ) is tremendously so that if you are not going to heat the ingredients together , honestly " its not worth doing "

as far as your contamination, it may cost abit more but " pyrotechnics as a hobby is not cheap" i swear by stainless steel balls.
great milling times, no contamination what so ever and as safe as houses, i use 5/8" ss.

Any stainless steal ball suppliers in the uk that spring to mind? i've only found chrome plated!

[BrightStar]

So if you want to keep your chemicals pure use ceramic balls!!
ffs

After many tens of hours milling rough BP ingredients, my 20mm ceramic media is showing some signs of wear. Some of the balls have shrunk a little, others have sparsely pitted surfaces.

It seems that any media will wear to some extent - we just have to work with it safely.

[fruitfulsteve]

After many tens of hours milling rough BP ingredients, my 20mm ceramic media is showing some signs of wear. Some of the balls have shrunk a little, others have sparsely pitted surfaces.

It seems that any media will wear to some extent - we just have to work with it safely.

I acquired mine from a friend that gave up manufacturing maybe 20 years ago, i'm not sure how much use they had(a lot i expect) but they still seem to be in very good condition with shiny surfaces even after i'd run them through the ball mill in a dilute HCL solution to give them a good clean(i washed the HCL of with plenty of water afterwoods) prehap as the old saying go's 'they don't make them like they used to' i'd still like some stainless steel ones though!!

[BrightStar]

i'd run them through the ball mill in a dilute HCL solution to give them a good clean

LOL - That's quite extreme - I tend to just run my mine with Fairy Liquid...

It does lead to an interesting thought though... We tend to optimise our mills for the best grinding (usually making the most noise) without much regard to the survivability of the media. I wonder if anyone has investigated it properly...

[starseeker]

LOL - That's quite extreme - I tend to just run my mine with Fairy Liquid...

It does lead to an interesting thought though... We tend to optimise our mills for the best grinding (usually making the most noise) without much regard to the survivability of the media. I wonder if anyone has investigated it properly...

I would have thought that lead would be bottom of the list,then stainless,then ceramic.

[GreenGenie]

Purity usually doesn't matter with BP. Let's face it BP was a real life product in the days before "AnalaR" and other indicators of purity!
With Nitrate most products over 95% will be fine. Sulphur whatever you can get will work, Charcoal really does need to be the correct wood but well made willow charcoal will work fine.

Thanks Arthur

I am milling lumpwood as I have been making cones with willow that work a little too well in my small garden and I wanted to see how they performed with lumpwood. Lumpwood is of coarse a lot cheaper. So if its less vigorous but still good enough, I will have a cheaper better balanced mix for my garden.

[GreenGenie]

the discoloration will be from the lead, ive used lead media for twelve months now and it doesn't seem to effect performance, you can switch to brass media but you'll need deep pockets, as for milling the kno3 and sugar i think you could get a sticky mess!, your best bet would be to get a cheap coffee grinder off ebay and grind up the sugar in that, ive got three of them one for fuels, oxidizers, and one for potassium benzoate( really painful to mill)

I have bought a coffee grinder for Pyro. I will give it a try. Good suggestion.

[GreenGenie]

GreenGenie

the lead was shiny as it was brand new, as in moulded 2 days earlier by my own hand. It does take a while for it to discolour on its own.

the discolouration is lead yes but dont forget that kn03 is a hard salt so will pick up some lead whereas charcoal and sulphur are softer so protect the lead more.

Thanks Phill

I didnt know lead could be made to shine. I have seen a lot of lead products. They all have a dull grey lustre; so I was a little surprise to see shiny balls. I assumed they had some kind of fine coating of something else.

The discolouration of the kno3 was also unexpected. Putting it in a beautiful snowy white and pouring it out slush grey. But I see theres nothing much to worry about technically though. I have much to learn and I am really enjoying the learning process. I learn something new every time I log on and there seems to be a wealth of well informed people on this site.

[GreenGenie]

As it happens i have been ball milling kno3 today, and because i had a fairly large amount to do i decided to do a bit of a study using ceramic balls and chrome plated steel balls in differant ball mills and jars, i concluded that the quickest was to use the steel media in a finned barrel, this got 250g of kno3 down to -200 mesh in 3hrs having said that the ceramic wasn't far behind in the finned barrel but both we're somewhat slower in the non finned barrel. Also the steel media has slightly contaminated the kno3 with the very small amout of rust on the balls. For chlorates i have ceramic media and a barrel that i only use for baclo3 and kclo3(feclo3 can be a bit unstable i've heard ). So if you want to keep your chemicals pure use ceramic balls!!
ffs

Thanks steve

When I bought the mill it didn't occur to me that there was an alternative to lead. Material containing steel sounded wrong and dangerous to me with sparks seeming a real possibility. Ceramic does sound good but I have lead now and the advice seems to be that there is no technical reason not to use lead. Though the dirty grey milled kno3 is certainly not as 'pretty' as the unmilled white.