[curiouscat]

Interesting, especially taking into account fact how common limestone is. How is the PCC prepared using this way better than mined calcite?

It must need a lot of energy to decompose limestone. And then one must slake it & get into solution & bubble CO2 to re-precipitate it?

CaSO4 is a textbook example of a weakly soluble salt. It is also a textbok example of a weakly soluble salt that is not that weakly soluble

Dang. Should have paid more attention in those Chemistry classes. 

[Borek]

Interesting, especially taking into account fact how common limestone is. How is the PCC prepared using this way better than mined calcite?

It must need a lot of energy to decompose limestone. And then one must slake it & get into solution & bubble CO2 to re-precipitate it?

Yes, but from the way gypsum is processed I don't see how the produced PCC is better than the one mined - and if so, I don't see a reason to convert gypsum to PCC (when the limestone, calcite and aragonite are so abundant everywhere).

I am not saying there is no reason, if it is done it makes sense - I just don't see it.

[chase]

The main aim is to make it energy efficient - they use high temperatures (1000 ^oC). 

So moving back to the separation.. After some digging around it seems that ferrofluid won't help as the densities need to be distinct or so I gathered. Any other suggestions?