Purifying Limestone Ammonium Nitrate (LAN 28)

[ANFO]

So I started a topic a while ago about making potassium nitrate out of ammonium nitrate and potassium hydroxide, because I struggle to get large quantities of KNO3 in South Africa.

 

I also mentioned that I actually don't have access to ammonium nitrate in large enough quantites, but that Limestone Ammonium Nitrate (LAN) fertilizer is sold widely here. I came up with the theory that because the lime in this mixture is calcium carbonate, that by simply mixing it in hot water I could separate the AN from the limestone (calcium carbonate is nearly insoluble at high temperatures, but AN is extremely soluble at high temperatures). That was my theory anyway.

 

But today I tried it out and it was a success. I poured some LAN into pre-boiled water, and the grey limestone immediately separated from the AN and precipitated at the bottom in a sludge. I then poured it through a coffee filter, and boiled the AN solution down until I had solid AN, completely free of limestone. It is a simple process, and it means I have access to large and cheap amounts of AN and in turn KNO3. So if any of you don't have access to AN, try find some LAN, and just do the above, worked like a charm

 

(The prilled grey stuff is the LAN, and the white flakes are the limestone free AN after boiling it down and scraping it up)

Edited August 24, 2012 by ANFO

[WILLIAM]

excellent! I am definately. going to try try it ,that was the answer i was trying to find on how to get rid of the lime stone and be left with pure amonium nitrate....