Abstract: A reactor for recovering metals such as copper, tin and lead from concentrated, acidic aqueous solutions includes a reaction vessel retaining a bed of scrap aluminum in a packed bed above the bottom of the vessel; a plenum below the packed bed of scrap aluminum, and a filter situated within the plenum, including a first perforated pipe enclosing a coaxial second perforated pipe, through which liquid can be filtered and withdrawn for recirculation into the reactor above the packed bed of scrap aluminum. Metal recovery is effected by reduction of metal ions in solution and precipitation onto the scrap aluminum. Multiple reactor systems including equipment required for pH adjustment of the wastewater also may be used.

Abstract: Heavy metals are reclaimed from a concentrated wastewater solution containing heavy metal cations and an acid by adding to the wastewater a bed of scrap aluminum in a total amount between about 160% and about 180% of the stoichiometric requirement for complete reduction of the dissolved heavy metal cations to their elemental states and adjusting the acid content of the wastewater to 5% to 20% by volume and allowing the heavy metal cations to react with the scrap aluminum to oxidize the aluminum and to reduce the heavy metal cations to their elemental states thereby producing demetallized wastewater which is neutralized with caustic to produce a treated effluent.