Abstract: A process and apparatus for hydrometallurgical leaching of unseparated, crushed mineral ores using a vessel having liquid stream forming nozzles in the lower portion thereof which operate to direct a stream of leaching liquid into solids in the lower portion of the vessel and to create a highly agitated interaction zone above which solids are settling under gravity and through which liquid from the lower portion rises upwardly in counter-current flow. The vessel is sufficiently high that an overflow of low solids content liquid is taken from the top. Outlets, as for example discharge piping or sumps, are provided in the bottom of the vessel for the controlled removal of solids therefrom. In multistage operation, the solids content of the overflow liquid is removed and the liquid content of the underflow is removed and combined to yield a mineral pregnant liquor which serves as the leaching liquid for a preceding stage where less depleted solids are being processed.