Selection of sorption materials for the extraction of nickel and cobalt from the ore of the Gornostaevskoye deposit

Abstract

Oxidized nickel ores account for the majority of industrial ores suitable for nickel production. The processing of such ores using traditional pyrometallurgical technology is not economically viable due to the low nickel content. One of the most cost-effective methods of processing oxidized nickel ores is sulfuric acid leaching technology followed by sorption extraction. The aim of this work is to establish the kinetic and thermodynamic parameters of the sorption extraction of nickel and cobalt using iminodiacetate chelating ion-exchange sorbents from various manufacturers, to select a desorbing solution and to determine the degree of desorption. The sorption of nickel and cobalt was carried out in a weakly acidic medium from a model solution containing impurities of other metals in static and dynamic modes. The limiting sorption capacity for the studied sorbents is 18-26 mg/g for nickel and 1-2 mg/g for cobalt in the static mode. The sorption capacity in the dynamic mode for nickel is equal to 25.5 g/L for Purolite S 930, 29.2 g/L for Lewatit TP 207, 1.4 g/L, and 1.8 g/L for cobalt, respectively. The best desorption parameters are achieved when using a 2 M sulfuric acid solution. The degree of desorption for sorbents Purolite S 930 and Lewatit TP 207 exceeds 90%. The use of the Lewatit TP 207 sorbent for the extraction of nickel from the leaching solution of nickel ore of the Gornostaevskoye deposit in 5 cycles made it possible to obtain a commercial desorbate with a nickel content of 18 g/L. The use of a part of the commercial desorbate obtained in the previous cycle, further strengthened to the initial concentration of sulfuric acid, for re-extracting nickel from the saturated sorbent during a cyclic process leads to a deterioration in desorption characteristics. It is recommended to remove the commercial desorbate from the process after several cycles of desorption and supply new solution of sulfuric acid for desorption to restore the sorption parameters.