Chemistry Forum

From what I can tell, phosphogypsum is simply gypsum (Calcium sulfate CaSO4·2H2O ) According to Wiki "Phosphogypsum refers to the gypsum formed as a by-product of processing phosphate ore into fertilizer with sulfuric acid. Phosphogypsum is radioactive due to the presence of naturally occurring...

Phosphogypsum, the gypsum formed as a by-product of processing phosphate ore into fertilizer with sulfuric acid, is radioactive due to the presence of naturally occurring uranium and radium in the phosphate ore. Ammonium carbonate reacts with gypsum to form ammonium sulfate and calcium carbonate. (N...

Isn't the anion sulfate SO4(2-)? http://en.wikipedia.org/wiki/Sulfate

I believe I read it's the second or third most prevalent ion in seawater. I have no formal chemistry training, so I'm not sure what I'm missing here.

Thanks,

Does anyone know whether NaOH and SO4 will react and what the products would be?

Thanks.

Does anyone know if sulfate (SO4--) will react with Ca++ or Mg++ to produce CaSO4 or MgSO4? If so, under what conditions? Is the reaction endo or exothermic?

Can you tell me whether (NH4)2CO3 + CaCl2 = CaCO3 + 2 NH4Cl is reversible? If I start with CaCO3 and 2 NH4Cl will I get (NH4)2CO3 and CaCl2 ?

Thanks.