Do an archive search on this site for more detailed info.
Ceramic media will not mill as fast as hard lead & often sparks.
Pottery supply houses often have used ceramic media at discount $, BUT
you do not know what used media has milled & how that will react with
your dreams. I mill pottery glaze & bought 50 lbs. of ceramic media
for roughly $35.
You may want to consider making two smaller mill jars. A jar roughly
the same dimensions as a large peanut butter jar weighs 14.75 lbs +
composition. I have a 6" X 24" jar that was filled once ... then I
tried to lift it ... I have never charged this jar.
Hard lead from wheel weights can be had for free. Using a Lyman bullet
mold ladle, single candle stick holders ($1.50 Goodwill), heavy lidded
pot ($8.00 Goodwill), toilet bowl seal for bees wax flux ($1.29). With
an old Colman stove, three candle stick holders, I can mold roughly 6
- 3/4" X 1" balls per minute.
Molding lead media is not very difficult IF YOU KNOW HOW & ARE SAFE.
Some folk prefer to have several jars & media dedicated per each group
of compositions to avoid contamination & washing jars & media ...
comet mix, BP can share a jar.
Some folk prefer to mill components then blend, keeping jar & media
'pure', then weigh each component after milling.
Never mill without knowing what chemicals react with sulfur. Never
mill with out knowing what compositions are too sensitive ...
Cheap mill practice keeps the Doctor's kids in college.