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Cleaning up the mill


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Posted

I recently got some barium nitrate, but it came in granular form. I figured since I have a mill, why not mill it down myself. I was milling BP today, and washed out the mill real good with soap and water, and also scrubbed my lead media down pretty good. The jar and media looked pretty squeaky clean, so I milled 1lb of BaNO3 for about 20 mins. I open the jar to find a dark brown powder emerge. I figure that the contamination was minimal, so I tried to make a green star batch to test. I made Kyle Kepley's Emerald green with no avail. The comp barely burned and the flame there was just orange with a trace of green. I thought that that batch was ruined, but the mill had to be clean now. I milled another pound of barium. This time, the product was still brown, but much lighter. I feel like I may have just wasted 2lb of barium nitrate, unless there is some way I can reclaim it. The only other thing this mill is used for is BP. The barium was snow white before I milled it.

 

If you have any suggestions, I would appreciate it greatly.

Posted (edited)

The major contaminant is going to be charcoal in this case, and that shouldn't really be causing you much trouble. Since charcoal is slightly "oily", it will stick to the inner surface of your jar and resist washing. Kyle's "Emerald Green" actually uses charcoal in the formula, so I think something else is going on here. Are you using your lead media to mill it?

 

Worst case scenario, if it's not performing well as a green coloring agent, and you've got some atomized aluminum, you've got a head-start on some beautiful glitter formulas :)

 

Win 7

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Win 31

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..all use barium nitrate and charcoal.

Edited by FrankRizzo
Posted
If it helps I've had great success cleaning out the mill by filling it with media, enough sand to cover the media and then topping it up 3/4 full with water & detergent, let it run a few hours, rinse it out, chuck out the sand, refill with sand & clean water, run a few hours and clean like new.
Posted

I use separate media for BP*, oxidizers & fuels then I have a couple jars & media I use for "Other." This stuff I clean by using some water and alcohol in the mill, or some other solvent depending on what it is I am cleaning out of there. I finally dedicated a jar to phenolic resin as well because I got tired of cleaning the stuff out of everything.

 

*gets used for some glitters and other comps that are OK using the same media.

Posted
I am using non hardened lead to mill it, but it has never given me much trouble before. I think I am going to try the sand and water idea next. I cant have this recurring.
Posted

I am using non hardened lead to mill it, but it has never given me much trouble before. I think I am going to try the sand and water idea next. I cant have this recurring.

 

The lead sloughs off and contaminates chems, use ceramic or other grinding media made for grinding. Zirc-M is my favorite, fast, clean, non absorbent and heavy. Best bet is to have dedicated jars and media, I have six jars for each type of job they are to perform, no cleaning necessary.

 

-dag

Posted (edited)

A few lbs of 120 silicon carbide grit does a great job cleaning-scouring out a BM jar.

 

I also use mostly Zirc "M" ceramic media for ball milling chemicals.

 

Generally, letting it tumble for awhile with hot soapy water & a couple stainless steel pot scrubber will clean it up.

 

If that doesn't do the job, I pressure wash it in a large colander.

 

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Edited by oldguy
Posted
Thanks for the input. I think I will hold off on milling the rest of the stuff until I can get new media and jars
Posted
It wasn't the barium nitrate that was contaminated? I got a kilo that wasn't cleaned from nitric acid a couple of years ago. After tips from the guys on the UKPS forum I neutralized the acid with potassium carbonate (a small amount of potassium nitrate won't destroy the green colour), dried it and milled it in my BP jar. I still use this barium nitrate, though I have mostly used it for Bleser White Mg, since I prefer barium chlorate for green.
Posted

Have you tried weighing the powder after it got out of the mill to see just how much contamination is in there?

 

I feel like I already know the answer to this, but did you bind the star composition into an actual star? Loose composition often behaves much differently and can give different colors than the bound formula.

 

Dissolving the barium nitrate in water and filtering will remove all the sulfur, charcoal, and lead contamination. I've been thinking about how I'd get rid of the potassium nitrate, but I haven't come up with a particularly good way without losing a lot of product. As Andy mentioned, if you have no other options, use it in glitters.

 

I would be uneasy about using sand to clean my mill. It will scratch the inside of the jar and the media giving contaminates extra places to hide. As well if there is residual sand in the mill, there is some worry about crystal fracture or sand on sand impact causing a spark. It's unknown if this would have enough energy to ignite anything however. I'd definitely stay away from sand if you ever intend on milling metals in that jar.

Posted
I did try burning as a loose powder as well as making a quick acetone bound star. Both still looked awful. I sure would hate to dedicate 2 pounds of barium to just glitter. although it wouldnt be the end of the world I suppose.
Posted
Bleser White Mg consists of 53% barium nitrate. That won't be destroyed by lead. :)
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