Recuperación de zinc proveniente de polvos de acería usando solventes eutécticos profundos (DES) : Recuperación de zinc proveniente de polvos de acería usando el DES etalina (etilenglicol + cloruro de colina) como agente lixiviante.

Abstract

Steel dusts are toxic waste from electric arc furnaces due to the presence of lead and cadmium, so their release into the atmosphere is harmful. Currently, they are processed by pyrometallurgical processes with recoveries greater than 90 % in the form of ZnO, while hydrometallurgical recoveries are greater than 75 %; however, most are laboratory-scale. To make the process of zinc recovery by hydrometallurgical route more environmentally friendly, it is proposed to use ethaline (EG:ChCl = 2:1) as a deep eutectic solvent for leaching. The present work seeks to evaluate the influence of temperature and the use of different oxidants in the recovery of zinc, as well as to assess electrodeposition. The highest recovery of zinc from zincite is 35.95 % at 90 °C because viscosity decreases and the interaction between DES and powders increases. The most effective oxidant is iodine with a recovery of 10.88 % due to its high solubility in ethaline. While, leaching kinetics follow the expression 1-(1-x)1/3=kt with an apparent velocity constant of 0.000868 h-1. Finally, from the electrodeposition, the cathode recovered zinc with a concentration of 69.33 % and an overall recovery of 0.039 % which can increase if the temperature and process time are increased.