How to remove stubborn tile adhesive?

Good evening everyone,

After visiting three hardware stores for advice and still being unsure (since three different recommendations were given), I am hoping for a tip or two here.

We removed tiles from the floor. What remains is the tile adhesive (see photos). With a 7cm wide chisel, I’m not really making much progress because the adhesive is extremely stubborn and doesn’t really come off. The adhesive is about 3-4mm high and spread over a spacious 70sqm. Later, 60sqm of parquet and 8sqm of tiles will be glued here.

What would you recommend? Thank you in advance!

First try the multitool, then the Hilti.

Loops.
Definitely do not drill (Hilti...) if you value the substrate.

As wrote, loops are best. There are discs (similar to concrete grinding discs) for such tasks. For the surface, rent a proper machine and don't forget the extraction.

Exactly - sand and vacuum very well while doing so. Just as a note: old tile adhesives may sometimes contain asbestos.

Thank you all. I've also heard about the asbestos. We will definitely wear respiratory protection, as the tiles are from 1979.

Regarding the grinding discs: and the others, do you have a photo or link for me showing what they should look like?