Set your sander to the lowest setting and be extremely careful not to grind up the surface of the tile.
Removing tile mortar from walls.
After removing the grout use a small pry bar or a similar tool to pry the tiles away from the wall.
Once those tiles loosen pry them off.
Use a chisel to scrape away the dried thin set carefully chipping it loose from the tile without scratching it or harming the tile itself.
Use the scraper to clean off large debris and then clean off any soapy residue with a damp cloth.
Use a ball peen or masonry hammer and cold chisel to tap the pieces free.
Start removing mortar from tile with the tiles free from the wall or floor you can now start cleaning them so can reuse the tile.
Be careful not to exert too much pressure downward on the tile or you could cause it to crack.
Removing tile from older style mortar walls can be very challenging.
It depends on a lot of variables in place at the time the tile was set but it comes down to how well the tile is bonded to the mortar.
Most likely though if the tiles were installed onto drywall the drywall will be damaged during removal.
There are inexpensive tools designed specifically for grout removal.
Wipe the tiles down with a dry rag.
Thinset mortar is generally used as the adhesive when tiling a wall.
Lay the tiles face down and use the putty knife to scrape across the tile back removing as much old mortar as possible.
Start by holding the tool horizontally or vertically in the case of vertical seams turning on the power and lightly pressing the blade to the grout.
Use the grout scraper to remove any thin set from the grout lines that is more than 40 of the tile thickness.
If the tiles are grouted you will have to clear the grout away first.
If any stubborn traces are left you may need to gently chisel it away or sand it off with a rotary sander and 50 grit sanding disk.
Sometimes you can get a flat chisel behind the tiles and pop them off one at a time almost whole.
In some cases the only way to tear out the ceramic tile is with heavy equipment such as a jackhammer or air chisel.
A wide blade putty knife is helpful in prying the tiles loose.
Tiles installed with thinset or another tile adhesive often require more work to remove them.
Always wear safety glasses when removing ceramic tile.
When the old tile falls off or is removed from the wall the thinset that was initially used to attach it has dried and become.