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Posted

Hi all

 

I`ve got a problem with my SrCO3.

I think its a really fine powder, fine enough for star compositions without ballmilling.

But it`s nor floating like Kclo4 or something else, it clumps together, these little lumps pass

through my finest screen.

Is this a normal characteristic for carbonates, or is it just not enough dry?

 

Probably I can put it in the ballmill, but I think this wont help, when I screen the chemicals

together, there will be again these tiny lumps...

 

 

greets

Posted
My experience is that even almost total non-hygroscopis chemicals, like strontium carbonate, can clump. One chemical supplier, that I have known for over ten years, said to me that some chemicals might clump just because of the particles being very small.
Posted

I've never noticed strontium or barium carbonates to float around much. I always attributed this to the higher density. It's the less dense materials like charcoal, lampblack, and flake Al that are really bad about floating. Some materials, no matter how dry, just wont float much, or flow freely.

 

How fine is your finest screen?

Posted

You're probably right about the density, Mumbles.

 

I have barium carbonate, barium nitrate, barium sulfate and barium chlorate. Just the nitrate seems a bit airfloat, and that is after milling it really fine.

 

I have strontium carbonate and nitrate. The nitrate might "dust" a little when milled very fine, just like the barium cousin, but for the most part it won't float at all.

Posted

I think my screen is around 70 mesh, finer screens are hardly available here in switzerland...

Finally I ballmilled my SrCO3 and it worked well, in my completed star comp I got still a few tiny lumps, but I

think this doesn`t matter.

Can I ballmill the SrCO3 together with Kclo4 for a better integrating of the chemicals?

 

 

 

Greets, PyroCube

Posted
All my finely powdered carbonates (Li, Sr, Ca, Ba) have a "waxy" texture and clumps together easily. I think ballmilling the carbonate with something that has a "dry" or "dusty" texture should alleviate the problem. I haven't tried it (and don't have a mill yet), so for those who do it, please report your results. For now, my formulas with carbonate have worked well enough even with specks of pure carbonate in the mix.
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