Portable rock crusher is designed to mainly crush coarse minerals like gold and copper ore, metals like steel and iron, glass, coal, asphalt, gravel, concrete to name but a few. Coal. It is capable of crushing coal to 0-20mm, 20-40mm, 40-100mm. Concrete. This kind of mobile asphalt crusher is able to break concrete to 0-20mm, 20-40mm, 40-100mm.