Next Article in Journal
Metal Removal from Acid Waters by an Endemic Microalga from the Atacama Desert for Water Recovery
Next Article in Special Issue
Initial Investigation into the Leaching of Manganese from Nodules at Room Temperature with the Use of Sulfuric Acid and the Addition of Foundry Slag—Part I
Previous Article in Journal
Microwave-Assisted Acid Activation of Clays Composed of 2:1 Clay Minerals: A Comparative Study
Previous Article in Special Issue
Leaching of Primary Copper Sulfide Ore in Chloride-Ferrous Media
Open AccessArticle

Column Leaching of Greek Low-Grade Limonitic Laterites

Technical University of Crete, School of Mineral Resources Engineering, University Campus, Kounoupidiana, 73100 Chania, Greece
Author to whom correspondence should be addressed.
Minerals 2018, 8(9), 377;
Received: 15 July 2018 / Revised: 15 August 2018 / Accepted: 29 August 2018 / Published: 31 August 2018
(This article belongs to the Special Issue Recent Advances in Hydro- and Biohydrometallurgy)
In this study, column leaching experiments were carried out to investigate the extraction of Ni and Co from low-grade limonitic laterites from Agios Ioannis mines in central Greece. Tests were carried out in laboratory Plexiglas columns using H2SO4 as leaching solution. Parameters determining the efficiency of the process, i.e., acid concentration (0.5 M or 1.5 M) and addition of 20 or 30 g/L of sodium sulfite (Na2SO3) in the leaching solution, were also studied. Upflow transport of the leaching solution with the use of peristaltic pumps was carried out, while the pregnant leach solution (PLS) was recycled several times over the entire test duration. The concentration of Ni, Co, Fe, Ca, Al, Mg, and Mn in the PLS was determined by Atomic Absorption Spectroscopy (AAS). The ore and the leaching residues were characterized by different techniques, i.e., X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and differential scanning calorimetry and thermogravimetry (DSC/TG). The experimental results showed that (i) Ni and Co extractions increased with the increase of H2SO4 concentration—60.2% Ni and 59.0% Co extractions were obtained after 33 days of leaching with 1.5 M H2SO4; (ii) addition of 20 g/L Na2SO3 in the leaching solution resulted in higher extraction percentages for both metals (73.5% for Ni and 84.1% for Co, respectively), whereas further increase of Na2SO3 concentration to 30 g/L only marginally affected Ni and Co extractions; and (iii) when leaching was carried out with 1.5 M H2SO4 and 20 g/L Na2SO3, its selectivity was improved, as deduced from the ratios Ni/Mg, Ni/Ca and Ni/Al in the PLS; on the other hand, the ratio Ni/Fe dropped as a result of the higher Fe extraction compared with that of Ni. View Full-Text
Keywords: limonitic laterites; column leaching; sulphuric acid; sodium sulfite limonitic laterites; column leaching; sulphuric acid; sodium sulfite
Show Figures

Figure 1

MDPI and ACS Style

Komnitsas, K.; Petrakis, E.; Pantelaki, O.; Kritikaki, A. Column Leaching of Greek Low-Grade Limonitic Laterites. Minerals 2018, 8, 377.

AMA Style

Komnitsas K, Petrakis E, Pantelaki O, Kritikaki A. Column Leaching of Greek Low-Grade Limonitic Laterites. Minerals. 2018; 8(9):377.

Chicago/Turabian Style

Komnitsas, Kostas; Petrakis, Evangelos; Pantelaki, Olga; Kritikaki, Anna. 2018. "Column Leaching of Greek Low-Grade Limonitic Laterites" Minerals 8, no. 9: 377.

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

Search more from Scilit
Back to TopTop