32 replies to this topic

[italteen3]

Ceramic media is non sparking, however it is slightly pourous which can lead to problems if you use it to mill anything other than BP, as long as you dont theres no problem. I have personally had better results by using hardened lead media and beefing up the motor so it can handle the torque.

No I believe ceramic media under certain conditions can spark. Lead and brass I believe are the only non-sparking types of media to use. I would not take a chance with the ceramic media.

[Chaoticentity]

i'll rephrase, I have never seen ceramic media spark at low tempatures, once a few years back I was doing using a Raku kiln (porcelin/stoneware cone 10+ so in excess of 2400 deg F) and dropped a red hot bowl from the firing kiln, this fragmented into very small pieces that went everywhere I suppose this could be sparking. The only sparking I've ever heard of in ceramic media was induced, that is that they milled several different mixtures, one of which reacted with another in the pourous structure.

I say this with the caveat that I would personally never use anything except hardened lead media. This stuff is tried and true and works. I believe that the balls rolling provides more grinding surface than anything else. I've tested BP after 4 hours in my mill that burned at 170cm sec (commerical air float, granular Kno3, and regular sulfur powder) this is with ~4lbs .60 cal lead muzzle loading balls in a lortone tumbler 12lbs capacity 2 6lb barrels. I would say that brass may be just a bit easier to aquire then lead balls, but that's in the USA so I have no idea of the restrictions in the UK.


I would also slow down the RPM's just a bit, I feel that the sliding/grinding action of the media does more good than a lift and drop. I found that slowing down my tumbler to around 75-80 rpm did a better job in a shorter amount of time. I have also found that milling dry was faster than milling wet. I get quite useable (160cm/sec or faster) powder after 4 hours instead of the 10-12 that it took before.

[Kembang Api]

BigG : Thank you very much for your advice, I had done 6.5 hours and 10 hours milling and the result after pressing and corning the Bp.
Well The lift was fantastic, It must be more than 15 feet in the air. or about 5 feet lower than the Chinese lift charge. I will work on the milling media ratio in few days. Thank you for your advice.

Creepin_pyro : Ceramic media is much better than any other media available (Lead, brass or glass) Lead is very dense and very heavy. This is the advantage, but very soft, will give lead contamination to the BP if used as a ball mill media. unless it is harden by mean of adding some Antimony and tin. I had been using it for a while until one day I realized that, why my lead ball media becoming smaller and smaller.
Ceramic ball on the other hand is much harder and denser than lead, It had 92% contain of Alumina oxide (Al2O3) and varieties of sizes available in the market. There are not prone to corrosion or contamination to other chemicals. It had a very fine surface, non-porous and non-spark too.
I had been reading some article in this forum about the harden lead media, but I never try them before.