What is the meaning of Sandblast?

To spray with fast-moving solid grains (such as sand propelled by compressed air, although softer material like sodium bicarbonate used for delicate materials may also be so referred to). The process is used for stripping dirt, rust, paint etc. from the surface of objects.

Sand driven by a blast of air or steam for cutting and engraving figures on glass or metal.

Source: wiktionary.org