A study of dissolution kinetics of a Nigerian galena ore in hydrochloric acid

In the present study, the recovery of valuable metals from a Panasonic Prismatic Module 6.5 Ah NiMH 7.2 V plastic casing hybrid electric vehicle (HEV) battery has been investigated, processing the anode and cathode electrodes separately. The study focuses on the recovery of the most valuable compounds, i.e., nickel, cobalt and rare earth elements (REE). Most of the REE (La, Ce, Nd, Pr and Y) were found in the anode active material (33% by mass), whereas only a small amount of Y was found in the cathode material. The electrodes were leached in sulfuric acid and in hydrochloric acid, respectively, under different conditions. The results indicated that the dissolution kinetics of nickel could be slow as a result of slow dissolution kinetics of nickel oxide. At leaching in sulfuric acid, light rare earths were found to reprecipitate increasingly with increasing temperature and sulfuric acid concentration. Following the leaching, the separation of REE from the sulfuric acid leach liquor by precipitation as NaREE (SO4)2·H2O and from the hydrochloric acid leach solution as REE2(C2O4)3·xH2O were investigated. By adding sodium ions, the REE could be precipitated as NaREE (SO4)2·H2O with little loss of Co and Ni. By using a stoichiometric oxalic acid excess of 300%, the REE could be precipitated as oxalates while avoiding nickel and cobalt co-precipitation. By using nanofiltration it was possible to recover hydrochloric acid after leaching the anode material.

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Dissolution kinetics of fluorapatite in the hydrochloric acid solution

Journal of Thermal Analysis and Calorimetry ◽

10.1007/s10973-017-6221-8 ◽

2017 ◽

Vol 129 (2) ◽

pp. 701-708 ◽

Cited By ~ 2

Author(s):

Khemaies Brahim ◽

Amira Soussi-Baatout ◽

Ismail Khattech ◽

Mohamed Jemal

Keyword(s):

Hydrochloric Acid ◽

Acid Solution ◽

Hydrochloric Acid Solution ◽

Dissolution Kinetics ◽

Kinetics Of

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Acidic leaching of iron from Kaoje Goethite ore by hydrochloric acid: Kinetics modelling

Nigerian Journal of Technology ◽

10.4314/njt.v39i3.20 ◽

2020 ◽

Vol 39 (3) ◽

pp. 800-806

Author(s):

K.I. Ayinla ◽

A.A. Baba ◽

S. Girigisu ◽

O.S. Bamigboye ◽

B.C. Tripathy ◽

...

Keyword(s):

Hydrochloric Acid ◽

Acid Leaching ◽

Dissolution Kinetics ◽

Second Phase ◽

Low Grade ◽

Iron And Steel ◽

Kinetics Modelling ◽

Shrinking Core ◽

Hcl Concentration ◽

Kinetics Of

Considering the recent focus of the Nigeria Government to grow and develop the nation’s economy through the solid minerals sector reform, this study has been devoted to the kinetics of a Nigerian goethite ore by hydrochloric acid leaching for improved iron and steel industries applications. This study was performed in three different phases. In the first phase, acidic leaching of iron from a goethite ore was examined and the influence of the operating variables including: HCl concentration, leaching temperature, stirring speed and particle sizes was examined experimentally. The optimum condition was found to be HCl concentration of 1.81M, temperature of 80°C, 200 rpm stirring speed and particle size 0.09 μm for iron in the range of investigated parameters. Under those conditions, the highest iron recovery was obtained to be 95.67 %. In the second phase, the dissolution kinetics of iron was evaluated by the shrinking core models. The finding reveals that diffusion through the fluid was the leaching kinetics rate controlling step of the iron. The activation energy (Ea) was found to be 14.54 kJmol-1 for iron. Equation representing the leaching kinetic of iron was achieved to be 1−2/3α - (1 − x)2/3 = 0.7272 × e−38.29/8.314×T × t. The final stage of the experiment was carried out by characterizing the leached residues by X-ray diffractometer (XRD) and scanning electron microscopy (SEM), the result showed majorly the presence of rutile (TiO2), anglesite (PbSO4), and traces of iron-silicate face like pyrite (FeS), quartz (SiO2). Keywords: kinetics modelling, leaching, low-grade, recovery, shrinking core

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Dissolution kinetics of Amazonian metakaolin in hydrochloric acid

Clay Minerals ◽

10.1180/claymin.2017.052.1.05 ◽

2017 ◽

Vol 52 (1) ◽

pp. 75-82 ◽

Cited By ~ 5

Author(s):

Paula E.A. Lima ◽

Rômulo S. Angélica ◽

Roberto F. Neves

Keyword(s):

Hydrochloric Acid ◽

Dissolution Kinetics ◽

Regression Coefficients ◽

Shrinking Core Model ◽

First Order ◽

Constant Size ◽

Shrinking Core ◽

Kinetics Of Dissolution ◽

Leaching Reaction ◽

Kinetics Of

AbstractThe kinetics of dissolution of Amazonian metakaolin in hydrochloric acid (HCl) was studied using the ‘Shrinking Core Model’ for spherical and ‘flat plate’ particles of constant size. The Amazonian kaolin was calcined at 700°C for 2 h. The calcined samples (metakaolins) were leached in an HCl solution with 5% excess at 70, 80 and 95 ± 3°C for 3 h. Samples were collected every 15 min and subjected to Al analysis by the EDTA titrimetric method. Experimental data showed that the spherical morphology produced a better fit with respect to the regression coefficients. The activation energy of the reaction was 90.6 kJ/mol. The chemical process is a first-order leaching reaction. The results of the present study are consistent with those from previous research on this topic, which used HCl with an excess of >90%.

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