Tiling on black stuff

[SL]

My bathroom floor used to have plastic looking tiles from the 1970's, and seemed to be stuck down with some black adhesive. (concrete floor) . I removed these tiles and tiled with ceramic tiles about 15 years ago.

I now re-doing my bathroom. The ceramic tiles where not loose but did come up fairly easy using hammer and bolster and left no trace of adhesive on floor.

Should I use any type of primer before laying new tiles?

 

[gcol]

Quote from the sticky:

What adhesive/grout
Solid floors - Concrete / Asphalt
The type of adhesive you use depends on the tiles you've selected. For regular ceramic tiles you can use a regular rapidset powdered adhesive. For porcelain tiles you need to ensure that the adhesive is suitable for use with porcelain tiles. You don't need any fancy adhesive for tiling onto solid floors - there's no reason to spend more than £10 for a 20kg bag. Feb fastset wall and floor tile adhesive is cheap and works very well.
Sweep, vacuum then mop the floor twice to ensure it's clean.
If the instructions on the adhesive recommend a primer then you should use it.
Powdered floor grout should be used - I recommend grey colour because most other colours look grubby quickly.