PROCESS TO SEPARATE HEAVY METALS IN INDUSTRIAL RESIDUES, EMPLOYING ULTRASONIC FLOATATION AND EUCALYPTUS AS SEQUESTER.

摘要

The present invention describes a process for necessary and sufficient heavy or toxic metals removal from residual, industrial or municipal waters and sludges, so that waters processed by floatation comply with ecological regulations. Tests were performed to remove heavy metals in industrial residual water samples from an electroplating plant. Said methodology comprises a two-stage ultrasonic floatation, using for the first one of the stages a collector (generally being heteropolar organic collectors), a foaming agent (generally being alcohols, surface action agents) which is a surfactant; for the second one, eucalyptus cones (cup-shaped receptacle) was used as a cooper sequester or other elements which were not separated in the first stage because of their amphoretic character, or because they are precipitates which are redissolved. In this way, given the excellent amounts of cooper, lead, nickel, iron and aluminum which were recovered, the treated industrial residual waters adequately complied with Mexican regulation NOM-066ECOL-1994. On the other hand, recovered solids are harmless metallic precipitates in a complex, inert state, which can be either deposited anywhere without any danger or, if they have a good metal concentration the same can be sent to a mineral concentrates foundry.