Cleaning/restoring old tiles

[bassman]

I'm renovating an old house (150 yrs old) and was going to lay a laminate floor in the kitchen in a black slate effect. I took up the old lino and found real black slate? tiles! These look like they are original to the house or at least pre ww2.

At some point a foam back carpet has been on them and this foam backing is stuck to most of the floor area. How best to clean the tiles and should I seal them afterwards and if so what with?

 

[TexMex]

I'd be inclined to use the end of a piece of wooden batten in a chissel like manner to remove the rubber backing, then scrub with soap and water. (is that a job for TrebleLady )

There must be thousands of products to seal the slate, I don't know enough about them to put forward a suggestion.