Hi dear Ted !

 Of course. For a good professional is obvious. I have used both in the form of phosphogypsum or ftorangidrit.  But I still compacting of raw mix at a high pressures. I always compacting all that fall into my hands. There are fine moments. SO3 at a certain temperature starts to fly and will be created a free lime.

With the best regards !

The whiteness of white cement is primarily determined by the Fe2O3 content of the white cement clinker. White cement is whiter than white clinker because it has a higher surface area.