Scale-Up Studies for Co/Ni Separations in Intensified Reactors.

Dimitrios Tsaoulidis,Marta Mayals Gañet,Milan Mamtora,Eduardo Garciadiego-Ortega,Panagiota Angeli

doi:10.3390/mi11121106

Dimitrios Tsaoulidis, Marta Mayals Gañet + Show 3 more

Open Access

https://doi.org/10.3390/mi11121106

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Journal: Micromachines	Publication Date: Dec 15, 2020
Citations: 1	License type: CC BY 4.0

Affiliation: University College London, University of Surrey

Abstract

In this paper, the effect of the scalability of small-scale devices on the separation of Co(II) from a binary Co(II)/Ni(II) mixture in a nitric acid solution by an organic Cyanex 272/TBP/kerosene (Exxsol D80) phase is studied. In particular, circular channels with diameters of 1, 2, and 3.2 mm are considered. The results were compared against those from a confined impinging-jets (CIJ) cell with a main channel diameter of 3.2 mm. The effects of total flowrate, residence time, Cyanex 272 concentration, and flowrate ratio on the mass transfer performance were investigated. It was found that at increased channel size, the throughputs were also increased but the extraction percentages remained the same. Higher extraction percentages were obtained by using the CIJ configuration at short residence times. However, for longer residence times, the mass transfer coefficients were similar and capillary channels should be preferred over the CIJ because of the ease of separation of the two phases at the end of the unit. The overall mass transfer coefficients ranged between 0.02 and 0.14 s−1 for the capillary channels during plug flow and between 0.05 and 0.45 s−1 for the CIJ cells during dispersed flow.

Highlights

Metals are central elements in everyday life; many have experienced an increase in demand in recent years due to their widespread use in industrial processes and consumer goods [1]
In particular, are among the most important non-ferrous metals, and they mostly appear together, making their separation a key process in hydrometallurgy [2]. Their superior strength under extreme temperatures, ductility, and corrosion resistance make them valuable materials for the manufacture of stainless steel and alloys, with uses in the chemical, petrochemical, and power generation industries. They are generally retrieved from sulphide and laterite ores, which are leached in acid solutions to give a pregnant leach solution that contains soluble salts of cobalt, nickel, iron, magnesium, and, at lower concentrations, chromium, aluminium, and manganese [3]
The separation and recovery of Co from Ni has mainly been conducted through direct solvent extraction from aqueous media by employing different types of extractants [5,6]

Summary

Introduction

Metals are central elements in everyday life; many have experienced an increase in demand in recent years due to their widespread use in industrial processes and consumer goods [1]. In particular, are among the most important non-ferrous metals, and they mostly appear together, making their separation a key process in hydrometallurgy [2] Their superior strength under extreme temperatures, ductility, and corrosion resistance make them valuable materials for the manufacture of stainless steel and alloys, with uses in the chemical, petrochemical, and power generation industries. The two immiscible liquids are brought into contact in the inlet at high velocities, increasing significantly the energy dissipation rates at this region [23] With this configuration, dispersed flow is formed, which exhibits very large specific interfacial areas available for mass transfer. Mass transfer coefficients are compared against those from confined impinging-jets (CIJ) cells for the same extraction system

Materials

Experimental Setup and Procedure

Results and Discussion

Separation during Flow—Effect of Scaling-Up