Rocks & mirror
Encyclopedia of Marine and Energy Technology

Angle of repose


The angle between the horizontal line and the side of the cone formed when the granular materials as grain, coal, sand or ores are poured onto a flat surface. The angle of repose of most grain loads ranges between 20° and 22°, but for barley it reaches 46°. The angles of repose for ores range between 34° for copper from Norway, and 60° for copper from Peru.