Leaching kinetics of cerussite using a new complexation reaction reagent

Wu, Dandan; Wen, Shuming; Deng, Jiushuai

doi:10.1039/c4nj01549e

Cited by 21 publications

(8 citation statements)

References 12 publications

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“…The leaching process of minerals was a solid–liquid reaction, and the kinetic behavior of the leaching reaction could be described by the unreacted shrinking core model. − The hydrometallurgical leaching of phosphate rock was a typical solid–liquid reaction, thus the kinetic behavior of the leaching reaction of phosphate rock conformed to that of the unreacted nuclear shrinkage model. The general expression of the leaching reaction is shown in eq . …”

Section: Resultsmentioning

confidence: 92%

Rigid-Flexible Combined Impeller Enhancement in Leaching of Phosphate Rock: a Kinetics Study

et al. 2021

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Conventional rigid impellers are frequently used in the leaching process of phosphate rock, which often form a symmetrical flow field in the reactor, leading to a reduction in the leaching efficiency. In this work, a rigid-flexible combined impeller was applied to the leaching process of phosphate rock to increase the leaching efficiency. The effects of the reaction temperature (T), sulfuric acid excess coefficient (ε), liquid−solid ratio (L/S), agitation speed (N), and leaching time (t) on the leaching of phosphate rock were investigated, and based on this, the leaching kinetics was studied. The results indicated that under the optimum parameters of a reaction temperature of 353 K, a sulfuric acid excess coefficient of 1.15, a liquid−solid ratio of 4.0 mL/g, an agitation speed of 280 rpm, and a leaching time of 120 min, the leaching rate of phosphate rock using the rigidflexible combined impeller reached 89.1%, which was 7.1% higher than that of the conventional rigid impeller under the same electric energy consumption. The leaching process complied with the unreacted core shrinking model, and the reaction rate was controlled by product layer diffusion. The apparent rate equation of the leaching process was 1 273 [N] 0.748 exp(−19.03 × 10 3 /RT)•t, and the apparent activation energy was 19.03 kJ/mol. The numerical simulation and analysis of the leaching residue showed that the system temperature in the rigid-flexible combined impeller system was homogenized, and the mixing effect of reactants was enhanced through the multiposition movement of the flexible connection piece in the axial direction, so that the reactants participated in the chemical reaction more efficiently.

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Section: Resultsmentioning

confidence: 92%

Rigid-Flexible Combined Impeller Enhancement in Leaching of Phosphate Rock: a Kinetics Study

et al. 2021

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“…The shrink core model was widely used to describe the kinetics, where a reaction between solid and liquid reactants occurs on the outer surface of the solid. 41 , 42 The kinetic model was described by three equations which are detailed in Table 2 .…”

Section: Results and Discussionmentioning

confidence: 99%

Leaching Kinetics of Vanadium from Calcium-Roasting High-Chromium Vanadium Slag Enhanced by Electric Field

2020

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Vanadium exists as multivalent valences in high-chromium vanadium slag, and it is hard to leach out in low valence. Electro-oxidation technology has been applied to enhance the leaching process of calcium-roasting high-chromium vanadium slag. The effect of parameters that affect the leaching efficiency of vanadium including concentration of sulfur acid, current density, reaction temperature, and liquid-to-solid ratio was investigated. The results showed that vanadium in low valence could be oxidized and efficiently leached out enhanced with electricity. The leaching kinetics was analyzed, which indicates that the leaching rate was controlled by the surface chemical reaction with an apparent activation energy of 40.11 kJ/mol. On the basis of this process, vanadium could be efficiently leached out with a leaching efficiency of 92.14% under optimal conditions: concentration of sulfur acid of 40 vol %, current density of 750 A/m 2 , reaction temperature of 90 °C, reaction time of 180 min, particle size under 75 μm, liquid-to-solid ratio of 4:1 mL/g, and stirring rate of 500 rpm. The relationship between the leaching efficiency and the parameters affecting the leaching process could be described as 1 – (1 – x ) 1/3 = K 0 × [H 2 SO 4 ] 0.1390 × [ J ] 0.03354 × [ T ] 2.8247 × [ L / S ] −0.2598 × exp 40.11/ T × t .

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“…Generally, the kinetics of a liquid–solid reaction is explained by the shrinking core model, and the following three kinetic equations can be applied for different rate-controlling steps. − where x is the extraction rate of rare earths, and k l , k c , and k d are the apparent rate constants which are calculated from eqs –, respectively.…”

Section: Resultsmentioning

confidence: 99%

Green Recovery of Rare Earths from Waste Cathode Ray Tube Phosphors: Oxidative Leaching and Kinetic Aspects

Yin

Tian

et al. 2016

ACS Sustainable Chem. Eng.

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In this work, we developed a green and efficient process for the recovery of rare earths from waste cathode ray tube phosphors. The mixture of hydrochloric acid and hydrogen peroxide was identified as the most suitable leaching agent due to the synergistic effect. The effects of various parameters on leaching process were explored, and the optimal conditions with stirring speed 600 rpm, temperature 313 K, 1 M of H2O2, 4 M of HCl, and leaching time of 90 min were determined. Furthermore, a possible reaction mechanism was proposed, and the kinetics for the leaching process was investigated in detail. The leaching process was found to follow a shirking-core model, with the chemical reaction as the rate-controlling step. The apparent activation energy of the reaction was calculated as 52.3 kJ/mol, and the reaction orders for H2O2 and HCl were established as 0.82 and 2.13, respectively. The kinetic equation was established. Moreover, the optimal leaching conditions were applied to the waste phosphors, and the oxalate precipitation process was employed, achieving the recovery rate of rare earths >99.5%. After calcining, a well crystallized (Y0.95Eu0.05)2O3 product with a purity of 99% was obtained with an average diameter of 5 μm.

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Leaching kinetics of cerussite using a new complexation reaction reagent

Cited by 21 publications

References 12 publications

Rigid-Flexible Combined Impeller Enhancement in Leaching of Phosphate Rock: a Kinetics Study

Rigid-Flexible Combined Impeller Enhancement in Leaching of Phosphate Rock: a Kinetics Study

Leaching Kinetics of Vanadium from Calcium-Roasting High-Chromium Vanadium Slag Enhanced by Electric Field

Green Recovery of Rare Earths from Waste Cathode Ray Tube Phosphors: Oxidative Leaching and Kinetic Aspects

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