Ceramic tile over Stained concrete

[Guyfromtexas]

I'm needing some advice to install porcelain 6x40 plank tile over a concrete floor that has been stained and urethane sealer on the surface. Tried a flooring buffer machine with 30 and 60 grit sandpaper but that just clogs the sandpaper up and doesn't do anything to get to concrete. I'm going to try a diamond disk grinder machine next but in the meantime, is there a stained floor type primer I can put down on it or some any other method of stripping the stain/sealer down to bare concrete?

 

[highup]

If it clogs up, that means it's removing material. Maybe it needs water to keep the loosened material in suspension. That might require a diamond disk on the buffer....... And a friend with a squeegee and wet vac to keep the liquid under control.
This isn't my profession, so I'm just adding a thought.