PERFECTIONNEMENTS APPORTES AUX PROCEDES DE SEPARATION DE METAUX CONTENUS DANS DES MILIEUX HYPERACIDES, PAR FLOTTATION IONIQUE

PROCEDE DE SEPARATION DE METAUX CONTENUS A DE FAIBLES CONCENTRATIONS DANS UN MILIEU HYPERACIDE.SELON CE PROCEDE, ON AJOUTE A UNE SOLUTION D'UN ACIDE CONCENTRE CONTENANT UN METAL A RECUPERER PRESENT A FAIBLE CONCENTRATION, UNE SOLUTION D'UN AGENT TENSIO-ACTIF ANIONIQUE EN QUANTITE TELLE QUE LE RAPPORT:CONCENTRATION DE L'AGENT TENSIO-ACTIFPH 1. Process for the separation of metals contained in low concentrations in an inorganic hyperacid medium, by ionic flotation by means of an ionic surface-active agent which plays the role of collector and which is taken particularly from the group of sulfhydrides and organo-phosphorus compounds, and selected from among those which possess at least one polar portion which confers on them a chelating character and at least one hydrocarbon chain of length greater than C6 which confers on them a hydrophobic character, and which are stable in hyperacid media, the surface-active agent being added in an amount such that the ratio vphi = Concentration of surface-active agent/ Concentration of metal >=3.5 and is preferably comprised between 3.5 and 8, to form a coprecipitate or a metal ion-surface-active agent complex, said process comprising in addition the formation of a foam in the hyperacid medium containing said coprecipitate or complex, by the introduction of a gas on the finally dispersed bubbles of which the coprecipitate or complex is absorbed which is recovered in the foam at the surface of the hyperacid medium.