NO NO NO NO! those tiles were fired at a temperature you would exceed in a firing. tiles and shelves are made of different materials. tiles need strength to support weight and are installed on a level surface to help with that. they do not also have to withstand extreme heat. look at a broken tile floor and you will see where some of the tiles were not supported correctly, causing the breakage.
Ok ok ok ok thanks for the advice and the enthusiasm For some reason I figured floor tiles to be high fire?