Question on used floor tiles

[rusty quoin]

7. Using them somewhere else...that is something I would have tried in my younger years.

It is labor intensive and it is all about protecting the integrity of the glaze while getting rid of the adhesive.
You start with scraping tools to knock it off. You then go to abrasives which creates a lot of dust. The abrasive part means orbital sanders, angle grinder fitted with abrasive pads...packed with many pads behind the one you use.

It's a matter of using the most aggressive tool first and finding out you are chipping the part you want to keep, you go to less aggressive, to the point you are hand sanding to get rid of adhesive that may show. The back of the tile can be aggressive, but move your wrist with the power tool to leave ups and downs so that the restored tile will set forever.

If you take on this job, I guarantee you, that you will be an expert in this. Me...I'd sell it or toss it.