Direct Acid Leaching of Sphalerite: An Approach Comparative and Kinetics Analysis

Rodríguez, Nallely Guadalupe Picazo; Aguilar, María de Jesús Soria; Martínez-Luévanos, Antonia; Almaguer-Guzman, Isaias; Chaidez-Félix, Josue; Pedroza, Francisco Raúl Carrillo

doi:10.3390/min10040359

Cited by 16 publications

(12 citation statements)

References 31 publications

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“…The chemical activation of raw materials with sulfuric acid solutions is also debated today [23][24][25][26]. The effect of the concentration and modulus of sulfuric acid on the decomposition of ilmenite was investigated repeatedly by [9,10,14,17,22,[27][28][29][30][31][32][33][34][35][36][37][38][39].…”

Section: Introductionmentioning

confidence: 99%

Sulfuric Acid Leaching of Altered Ilmenite Using Thermal, Mechanical and Chemical Activation

et al. 2020

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The kinetics of the sulfuric acid leaching of altered ilmenite, mechanisms, and process intensification methods were studied. The effect of changing the chemical composition during grinding was determined. The content of ilmenite and pseudorutile decreased from 5.3% to 3.1% and from 90.2% to 63.1%, respectively. Rutile increased from 4.5% to 28.7%, while a pseudobrookite new phase appeared in the amount of 5.1% after 2 h of grinding. It was found that the modification of raw material by sulfuric acid led to the increase of the decomposition rate, and at the same time, decreased when the ore was utilized due to an increase of insoluble TiO2 content. Isothermal conditions were evaluated with H2SO4 concentration varying from 50 to 96%. The data obtained were described with the approximation of the contracting sphere model. It was shown for the first time that H2SO4 > 85 wt% causes a sharp constant decrease of titanium. Correlating these phenomena allows for the consideration of H2SO4·H2O as reagents, rather than H2SO4 molecules. It was experimentally proven that at a temperature above 190 °C, the Ti leaching degree dropped, which is explained by the formation of polymerized TiOSO4. Finally, it was shown that adding NaF reduced the activation energy to 45 kJ/mol.

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Section: Introductionmentioning

confidence: 99%

Sulfuric Acid Leaching of Altered Ilmenite Using Thermal, Mechanical and Chemical Activation

et al. 2020

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“…As can be seen from Equations (3) and (4), zinc(II) sulfide leaching requires the addition of dissolved oxygen, whereas zinc(II) oxide does not. In addition, as studies of the leaching of Zn(II) from sphalerite in an acidic environment have shown, elemental sulfur [ 39 , 40 , 41 , 42 , 43 , 44 , 45 ], as well as other insoluble salts (lead(II) sulfate(VI) and barium sulfate(VI)), may form on the surface of zinc(II) sulphide, hindering further leaching [ 39 , 46 , 47 ]. ZnO + H 2 SO 4 → ZnSO 4 + H 2 O 2 ZnS + 2 H 2 SO 4 + O 2 → 2 ZnSO 4 + 2 S + 2 H 2 O …”

Section: Resultsmentioning

confidence: 99%

Two-Stage Leaching of PCBs Using Sulfuric and Nitric Acid with the Addition of Hydrogen Peroxide and Ozone

Lisińska,

Wojtal,

Saternus

et al. 2023

Materials

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The paper presents the possibility of recovering metals from printed circuit boards (PCBs) of spent mobile phones using the hydrometallurgical method. Two-stage leaching of Cu(II), Fe(III), Sn(IV), Zn(II), Ni(II) and Pb(II) with H2SO4 (2 and 5 M) and HNO3 (2 M) with the addition of H2O2 (10 and 30%) and O3 (9 or 15 g/h) was conducted at various process conditions (temperature—313, 333 and 353 K, time—60, 120, 240, 300 min, type and concentration of leaching agent, type and concentration of oxidant, solid–liquid ratio (S/L)), allowing for a high or total metals leaching rate. The use of two leaching stages allows for the preservation of selectivity, separation and recovery of metals: in the first stage of Fe(III), Sn(IV) and in the second stage of the remaining tested metal ions, i.e., Cu(II), Zn(II), Ni(II) and Pb(II). Removing Fe from the tested PCBs’ material at the beginning of the process eliminates the need to use magnetic methods, the purpose of which is to separate magnetic metal particles (ferrous) from non-magnetic (non-ferrous) particles; these procedures involve high operating costs. Since the leaching of Cu(II) ions with sulfuric(VI) acid practically does not occur (less than 1%), this allows for almost complete transfer of these ions into the solution in the second stage of leaching. Moreover, to speed up the process and not generate too many waste solutions, oxidants in the form of hydrogen peroxide and ozone were used. The best degree of leaching of all tested metal ions was obtained when 2 M sulfuric(VI) acid at 353 K was used in the 1st research stage, and 2 M nitric(V) acid and 9 g/h O3 at 298 K in the 2nd stage of leaching, which allowed it to be totally leached 100% of Fe(III), Cu(II), Sn(IV), Zn(II), Ni(II) and 90% Pb(II).

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“…In sample PL_4, willemite was partly dissolved after the 1 st extraction step, and disappeared completely after the 2 nd extraction (Table 1). The dissolution kinetics of Zn depends on the type of the oxidant used for leaching [41]. H2O2 (8.8 mol/l), used in the 3 rd step of the BCR SE procedure does not completely oxidize ZnS, most likely due to slow oxidation kinetics [42].…”

Section: Mine Waste Samplesmentioning

confidence: 99%

Characterization of Mine Waste from a Former Pb–Zn Mining Site: Reactivity of Minerals During Sequential Extractions

Cappuyns

Campen

Bevandić

et al. 2021

J. Sustain. Metall.

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An integrated mineralogical and chemical characterization approach was applied to different types of mine waste collected from the ancient Pb-Zn mining area of Plombières. The combination of different methods to determine (pseudo-)total element concentrations, sequential extractions and quantitative mineralogical analysis provided detailed information on the reactivity of minerals in the waste, as well as the associated metal(loid) release under different experimental conditions. Lithium borate (LiBO2) fusion was not suited to determine total metal(loid) concentrations in the investigated mine waste samples, due to the incomplete dissolution of the samples, and the volatilization of As and Cd during the fusion. Because some elements were below detection limit of X-ray fluorescence spectrometry (e.g. Cd), aqua regia digestion was useful to complement the chemical sample characterization, bearing in mind that only pseudo-total concentrations could be determined. Galena (PbS) and its alteration products cerussite and anglesite (PbSO4) were the main lead minerals associated with the mining waste. Because of the high cerussite (PbCO3) content of the investigated samples (2-5 wt%), Pb shows the highest potential for recovery from the mining waste, but it also poses the highest environmental and human health risk. Zinc minerals showed a lower reactivity towards the BCR sequential extraction (sphalerite, ZnS) or were less abundant (willemite, Zn2SiO4). Quantitative XRD analysis allowed for better evaluation of the incomplete dissolution of some minerals, improving the interpretation of the sequential extraction results.

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Direct Acid Leaching of Sphalerite: An Approach Comparative and Kinetics Analysis

Cited by 16 publications

References 31 publications

Sulfuric Acid Leaching of Altered Ilmenite Using Thermal, Mechanical and Chemical Activation

Sulfuric Acid Leaching of Altered Ilmenite Using Thermal, Mechanical and Chemical Activation

Two-Stage Leaching of PCBs Using Sulfuric and Nitric Acid with the Addition of Hydrogen Peroxide and Ozone

Characterization of Mine Waste from a Former Pb–Zn Mining Site: Reactivity of Minerals During Sequential Extractions

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