Stains are never a pleasure to deal with, but when the stain can be removed easily, it makes the job less stressful. Slate stone comes in a variety of natural colors and designs. If it has some dirt or rust buildup, you most likely will not be able to notice it. However, just because you cannot see it, does not mean you should not clean it. Slate tile requires regular maintenance, and rust buildup should be removed as soon as it is noticed.
Clean the rusty surface of the slate tile with a sponge and cold water. Remove as much excess dirt and other buildup as necessary to remove the stain. Never use hot water because that helps stains set quicker, rather than lift them up.
Combine your poultice mixture. This could be water mixed with a jar of name-brand poultice powder, or you can make your own mixture with baking soda and peroxide. Poultice is simply what you would call a dressing that covers an object to remove a stain or help heal something.
Apply the mixture with your hands to the rust stain. Spread it out evenly, but keep it thick enough so it can absorb into the slate and then harden.
Cover the area with plastic wrap and tape down the edges. Make a few small pin holes around the top of the plastic wrap to let only a small amount of air make its way through and escape.
Allow to dry for 24 to 48 hours. Then remove the plastic wrap.
Scrape away the poultice covering with a plastic scraper. Then buffer the area with a soft cloth.