Sciencemadness Discussion Board

Solubility of...(fertilizer)

12AX7 - 14-4-2005 at 22:52

I found a thing of bulb fertilizer in the basement, I forget the rating offhand but it contains AN, calcium phosphate, potassium phosphate and potassium sulfate. I ground some down (since it's coated in some shell ("Osmocote";) that slows it down to oh four months dissolution time), oh and it cools the solution nicely when dissolved, as I'd expect, :) well anyway I decanted off the insolubles (non-broken-down shells and calcium phosphate), boiled the solution a little and then froze it.

It was probably 10-20°F, cold enough that frost formed on it. Some nice long crystals formed, on decanting and drying (during drying, the little water left by capillary action dissolved it totally at 212°F) I crushed some with charcoal and it burned slowly with a purple flame, hmmm potassium nitrate :D

Long story short (oops, the above is long, so much for that), which of the ions are least soluble, and how much does it vary with temperature? Obviously, I already got some KNO3 from it, but what of the phosphate, sulfate and ammonium (and any remaining nitrate) in solution?

More succinctly, how can I refine this into the component phases, and what will I get?

Tim