Sciencemadness Discussion Board

saltpeter again

CrossxD - 31-7-2017 at 03:02

hello guys, :D

I found quite cheap fertilizer calcium ammonium nitrate and I want to make potassium nitrate from potassium chloride

both of my reactants are impure CAN is about 95% and my KCl is about 80% impurities are insoluble and in KCl there are sulphates, magnesium, sodium and little bit of calcium

1079 grams of CAN should react with 814 grams of KCl if it is quantitative

solubiliti of KCl is 28 grams at 0 celsia and 58 at 100 celsia (in 100grams of water) for potassium nitrate is 13 grams at 0celsia and 242 grams at 100 celsia

how much of water should I use to (max) crystalise of KNO3 but not any (or lowest possible) KCl

Foeskes - 31-7-2017 at 04:09

Does your fertilizer contain phosphates?

CrossxD - 31-7-2017 at 04:20

No it doesnt
only sulphates sodium and magnesium as impurities

hissingnoise - 31-7-2017 at 06:32

Quote:
how much of water should I use to (max) crystalise of KNO3 but not any (or lowest possible) KCl


In producing KNO3 from Chilean NaNO3, boiling, saturated solutions were mixed and left overnight to crystallise...

XeonTheMGPony - 31-7-2017 at 07:26

well if you want to simplify the reaction:

Take your CaN/AN mix, dissolve in clear cheap ammonia keep adding it till you stop seeing a precipitate forming. Filter this off, take the liquid and boil down under low heat till you see a crystal skin forming on the surface.

Take off heat, this will be concentrated ammonia nitrate. Now do the same with your potassium chloride, add to boiling water till no more dissolves. Filter and then cool to room temp, then place in the freezer over night, rinse and repeat till you have enough purified KCl.

I'd save the mother liquor as well and boil it down for a second crop of less pure KCl to have on hand for testing.

Dissolve KCl in water slightly over saturation point and dilute the A.N. solution as well till no apparent crystals are visible.

Add together stir well, heat till hot to the touch then allow to cool to room temp slowly and watch the crystals drop out of solution, boil down if necessary.

hissingnoise - 1-8-2017 at 03:02

Quote:
well if you want to simplify the reaction:

Take your CaN/AN mix, dissolve in clear cheap ammonia keep adding it till you stop seeing a precipitate forming. Filter this off, take the liquid and boil down under low heat till you see a crystal skin forming on the surface.


All that's needed to obtain NH4NO3 from C.A.N. is filtering off CaCO3 and concentrating the soln..

Why would you want to waste your NH4OH (cheap or otherwise?) to no useful effect?


XeonTheMGPony - 1-8-2017 at 06:15

because it converts the calcium nitrate to ammonium nitrate and precipitates out the Ca as CaOH

So rather use-full in my books! and 2 dollars for 4L of moderately strong ammonia water hardly a waste if one where to just pour it down the drain!

The ammonia Nitrate is the far far more valuable compound!

Solubility in water‎: ‎anhydrous: 1212 g/L (20 °C) CaNO3

I'd like to know what magic water you been using to simply filter it out!

[Edited on 1-8-2017 by XeonTheMGPony]