Lixiviación de zinc y plomo de un concentrado de esfalerita y galena proveniente de la zona minera Chinapintza (Zamora Chinchipe, Ecuador), empleando solventes eutécticos profundos.

Abstract

Solvometallurgy is a technique of the Extractive Metallurgy that uses molecular organic solvents, ionic liquids or deep eutectic solvents (DES) instead of aqueous solutions. This technique has numerous applications. Currently in Ecuador, concentrates rich in zinc and lead are exported to other countries to be refined. However, the use of deep eutectic solvents appears as an alternative and novel technology for the recovery of these metals in the country. The physical, chemical, and mineralogical characterization of sphalerite and galena concentrate from the Chinapintza mining area was carried out. The experimentation started with roasting tests for the sulfides presents in the concentrate, in order to oxidize the mineral species and increase their solubility in the leaching tests. Then, the concentrate was leached with 3 deep eutectic solvents (reline, ethaline, and glycine) for zinc and lead recovery. At the same time, acid leaching tests were carried out with sulfuric acid and nitric acid to compare the dissolution of the metals of interest in the two media (organic and acid). The results obtained showed that DES are better lixiviants than acidic media and that they do not require prior treatment of the sample for their effectiveness. In addition, tests showed that they are more selective for lead in any of its mineral forms (sulfides, sulfates, or oxides). In the concentrate, about 99% of lead was recovered, and zinc in smaller quantities using reline.