hydraulic mining | Britannica
hydraulic mining, use of a powerful jet of water to dislodge minerals present in unconsolidated material, including mine tailings, placer deposits, alluvium, laterites (soil rich in iron oxides), and saprolites (soil rich in clay). It has also been applied to consolidated materials from sandstones through coal to hard rock. Hydraulic mining encompasses hydraulicking, sluicing, and educing.
