Evaporation of Ammonium Sulphate

[willowenergy]

We are trying to evaporate large quantities of ammonium sulphate (which is a byproduct of a pharmaceutical extraction process). The dissolved solids is supposed to be 25%. It contains 6% ammonia, 6% sulphur, 5000mg/k potassium and <10mg/kg of metals. I wonder how much i can evaporate using an industrial evaporator which can recirculate the product. The client thinks it cannot be reduced to less than 30% becuase of the "dissolved solids". But i think it is feasible, in fact down to around 5%....but am i just losing organic contaminants, ammonia, etc to the atmosphere to get a result that low??

Thanks.

 

[25362]

Do you mean to evaporate water i/o to precipitate the salt crystals as a solid ?

 

[djack77494]

Industrial evaporators are capable of generating supersaturated solutions. You can certainly go to saturation without much difficulty.

 

[StoneCold]

Try it in a beaker and analyze the concentrated mixture and the distillate and look at the mass balance. Nothing like a little experiment to boost your confidence in the result.

StoneCold

 

[25362]

Sodium sulfate starts to decompose at about 100 deg C. You should use vacuum. Besides, the dihydrate contains ~20.2 % water.

 

[25362]

Sorry for the mixup. I should have said ammonium sulfate. The dihydrate contains somewhere above 21% water. The rest is OK.