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Khanifa Mzee

How can we prevent urea crystals?

Donald Pearline  Follow

We have tried that but could not get any result.

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Biniam Berhane  Follow

Dear Christian,
Thank you for your advice. We were able to dissolve urea with warm water. But that system is not available anymore as in industrial measure. Even if I could use warm water, the storage temperatures drops more below than 20 ºC. And alsa I should keep %21 of nitrogen in the solution. So I can not use less urea. Urea's NPK nutrient rating is 46-0-0. As in the formulation I gave above, it is like, %47 of Urea x %46 = %21 of N from Urea. We should keep the Nitrogen value as %21.
Regards,
Ferhat ÖZMUTAF

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Charlie  Follow

 Add 1% monoethlene glycole .

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Angela Shingler  Follow

Dear Prem Baboo,
Thank you for your reply. We are not able to maintain the temperature of the solution, until the costumer use this product. Because, for example, after mixing 2500 kg of the solution, we fill the solution in the 20 L co-ex bottles. And keep them in the storage. Even if we could maintain the temperature of the storage, the costumer probably wouldn't be careful about that. And urea crystals will occur in the bottle. So we'd get feedback of complaints. I'm looking for an ingredient to add in the solution to prevent urea to get crystallize.
Regards.

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Ben Boyarko  Follow

This topic is very interesting, where can I find more information about thermodynamics of fertilizers. Do you have any reference, actually I have only spot information about it.

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Andy Cairns  Follow

Dear Ferhat,
One should distinguish two separate things: (1) the solubility of urea related to temperature (2) and the heat required to dissolve it in water. The dissolution of urea in water is endothermic, consuming 58 cal / g. If you prepare the solution with water warm enough to not crystallize when the temperature drops, you should have no further problems if storage temperatures correspond to concentrations recommended solutions:
Temperature (ºC)    g/100 g sc
20                                52
30                                62.5
60                                71.5
80                                80
100                              88
Regards,
Cristian Vera

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Dave Hunter  Follow

Dear Prem Baboo,
Thank you for your advice. But we're trying to manufacture a 21-3-3 liquid fertilizer. The formulation we use:
1. Phosporic Acid %5
2. KOH %5
3. Urea %47
4. Water %43
Which ingredient should we change or include?
Regards.

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Becca Altic  Follow




Dear Ferhat,
To avoid crystallization of the urea solution the temperature of the solution may  be maintained as per attached crystallization curve, The steam or electric heater may  be provided for maintaining temperature.
Regards,
Prem Baboo

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Alexander Streng  Follow

Dear Ferhat
You may be changed concentration(Composition) of the solution or ratio of NPK to be changed one sample of ratio,You may be mixed liquid fertilizers composition is following
1.       Ammonium Nitrate                      45%
2.       Urea                                            36%
3.       Di  Ammonium Phosphate-       1%
4.       Water(DM)                                 18%
Di Ammonium Phosphate or mono ammonium phosphate the concentration of solution of P2O5=0.5% in the presence of P2O5 reduced chemical corrosion in simple Iron vessel which is contain in 25 kg capacity vessel of Iron.If you are using PVC vessel then P2O 5 not required, but it also as a P nutrient.
Properties of ” sample”
1.       N=32% liquid fertilizer
2.       Colourless solution
3.       Sp. Gr=1.3
4.       Liquid at 0 0C
5.       It is stored for many days
6.       It is neutral fertilizer for all types of crops and soil.
7.       (I) Ammonium Nitrate  -    7.7%
(ii) Nitrate Nitrogen      -     7.7%
(iii) Urea Nitrogen         -     16.6%
Regards,
Prem Baboo

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