Documents disponibles écrits par cet auteur

Determination of the solubility products in water at 20 °C of 32 metallic carboxylates / Stéphanie Mauchauffee in Industrial & engineering chemistry research, Vol. 47 N°20 (Octobre 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 N°20 (Octobre 2008) . - P. 7533-7537 Titre : Determination of the solubility products in water at 20 °C of 32 metallic carboxylates Type de document : texte imprimé Auteurs : Stéphanie Mauchauffee, Editeur scientifique ; Eric Meux, Editeur scientifique ; Michel Schneider, Editeur scientifique Année de publication : 2008 Article en page(s) : P. 7533-7537 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Metallic  carboxylates  Carbons Résumé : The solubility products of 32 metallic carboxylates resulting from the precipitation of seven cations (Cd, Co, Cu, Mn, Ni, Pb, and Zn) with six linear saturated carboxylates (heptanoate, octanoate, nonanoate, decanoate, dodecanoate, and octadecanoate) are reported. Solubility measurements were performed using the analytical method with freshly precipitated metallic carboxylates. From the measured metal concentration and equilibrium pH value, solubility products, Ksp, were determined. The results indicate a linear relationship between the negative logarithm of the solubility product and the carbon number in the aliphatic chain that is valid from 7 to 12 carbons. The determination of the pKsp value of copper octadecanoate shows the limit of the linear model. Indeed, the experimental value obtained demonstrates that pKsp tends to a limiting value and becomes independent of the chain length. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071595a [article] Determination of the solubility products in water at 20 °C of 32 metallic carboxylates [texte imprimé] / Stéphanie Mauchauffee, Editeur scientifique ; Eric Meux, Editeur scientifique ; Michel Schneider, Editeur scientifique . - 2008 . - P. 7533-7537. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N°20 (Octobre 2008) . - P. 7533-7537 Mots-clés : Metallic  carboxylates  Carbons Résumé : The solubility products of 32 metallic carboxylates resulting from the precipitation of seven cations (Cd, Co, Cu, Mn, Ni, Pb, and Zn) with six linear saturated carboxylates (heptanoate, octanoate, nonanoate, decanoate, dodecanoate, and octadecanoate) are reported. Solubility measurements were performed using the analytical method with freshly precipitated metallic carboxylates. From the measured metal concentration and equilibrium pH value, solubility products, Ksp, were determined. The results indicate a linear relationship between the negative logarithm of the solubility product and the carbon number in the aliphatic chain that is valid from 7 to 12 carbons. The determination of the pKsp value of copper octadecanoate shows the limit of the linear model. Indeed, the experimental value obtained demonstrates that pKsp tends to a limiting value and becomes independent of the chain length. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071595a

Hydrometallurgical treatment for valuable Metals recovery from spent CoMo/Al2O3 catalyst. 1. improvement of soda leaching of an industrially roasted catalyst / Vincent Ruiz in Industrial & engineering chemistry research, Vol. 50 N° 9 (Mai 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 9 (Mai 2011) . - pp. 5295–5306 Titre : Hydrometallurgical treatment for valuable Metals recovery from spent CoMo/Al2O3 catalyst. 1. improvement of soda leaching of an industrially roasted catalyst Type de document : texte imprimé Auteurs : Vincent Ruiz, Auteur ; Eric Meux, Auteur ; Sebastien Diliberto, Auteur Année de publication : 2011 Article en page(s) : pp. 5295–5306 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Metal  Catalyst Résumé : This paper describes the recovery of molybdenum from a spent CoMo/Al2O3 by soda leaching after a roasting step. First, the leaching was performed on a catalyst industrially roasted at 800 °C during 20 min. In order to reach a molybdenum leaching yield higher than 85%, the process was optimized using a 23 design of experiments with parameters such as NaOH amount, leaching time, and temperature. Unfortunately, in the best leaching conditions defined by the factorial design, the leaching yield of molybdenum never exceeded 60% because of an incomplete roasting of the catalyst proved by the X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis of the residue. In a second part, the roasting was investigated on an unroasted catalyst containing 23.9% Al, 11% Mo, 2.9% Co, 7.9% S, and 6.3% C using a central composite design. By changing the thermal treatment conditions (700 °C, 20 min) and performing the best soda leaching conditions (an amount of sodium hydroxide equal to the twice of the required stoichiometry and a leaching time of 4 h at 60 °C), it was possible to extract more than 90% of molybdenum initially present in the catalyst. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102414d [article] Hydrometallurgical treatment for valuable Metals recovery from spent CoMo/Al2O3 catalyst. 1. improvement of soda leaching of an industrially roasted catalyst [texte imprimé] / Vincent Ruiz, Auteur ; Eric Meux, Auteur ; Sebastien Diliberto, Auteur . - 2011 . - pp. 5295–5306. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 9 (Mai 2011) . - pp. 5295–5306 Mots-clés : Metal  Catalyst Résumé : This paper describes the recovery of molybdenum from a spent CoMo/Al2O3 by soda leaching after a roasting step. First, the leaching was performed on a catalyst industrially roasted at 800 °C during 20 min. In order to reach a molybdenum leaching yield higher than 85%, the process was optimized using a 23 design of experiments with parameters such as NaOH amount, leaching time, and temperature. Unfortunately, in the best leaching conditions defined by the factorial design, the leaching yield of molybdenum never exceeded 60% because of an incomplete roasting of the catalyst proved by the X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis of the residue. In a second part, the roasting was investigated on an unroasted catalyst containing 23.9% Al, 11% Mo, 2.9% Co, 7.9% S, and 6.3% C using a central composite design. By changing the thermal treatment conditions (700 °C, 20 min) and performing the best soda leaching conditions (an amount of sodium hydroxide equal to the twice of the required stoichiometry and a leaching time of 4 h at 60 °C), it was possible to extract more than 90% of molybdenum initially present in the catalyst. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102414d

Hydrometallurgical treatment for valuable metals recovery from spent CoMo/Al2O3 catalyst. 2. oxidative leaching of an unroasted catalyst using H2O2 / Vincent Ruiz in Industrial & engineering chemistry research, Vol. 50 N° 9 (Mai 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 9 (Mai 2011) . - pp. 5307-5315 Titre : Hydrometallurgical treatment for valuable metals recovery from spent CoMo/Al2O3 catalyst. 2. oxidative leaching of an unroasted catalyst using H2O2 Type de document : texte imprimé Auteurs : Vincent Ruiz, Auteur ; Eric Meux, Auteur ; Michel Schneider, Auteur Année de publication : 2011 Article en page(s) : pp. 5307-5315 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Hydrogen  peroxide  Lixiviation  Oxidation  Catalyst Résumé : This study deals with the feasibility of the oxidative leaching of molybdenum and cobalt sulphides contained in a spent hydrodesulphurisation catalyst using H2O2 in acidic medium. The study was first carried out with MoS2 in order to define the important parameters of the leaching procedure and then applied to an unroasted CoMo/Al2O spent catalyst containing 11 wt % of Mo and 2.7 wt % of Co. In both cases, a 23 factorial design was used. The results obtained with MoS2 highlighted the necessity to limit the increase in temperature of the medium to minimize the decomposition of H2O2 and the necessity to keep pH constant to avoid an important acidification of the medium which could cause dissolution of alumina matrix when leaching will be applied to spent catalysts. The oxidative leaching of the unroasted CoMo/Al2O3 spent catalyst was performed without previous grinding. In a single-step, at pH = 1.3 with a stoichiometric factor equal to 2.4, an L/S ratio equal to 7.5, and an H2O2 concentration of 3.75 mol·L―1, it was possible to recover molybdenum and cobalt simultaneously with leaching yields of 90% and 83%, respectively, without dissolving more than 8% Al. In these conditions, the maximal temperature recorded during the experiment was about 60 °C. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24128652 [article] Hydrometallurgical treatment for valuable metals recovery from spent CoMo/Al2O3 catalyst. 2. oxidative leaching of an unroasted catalyst using H2O2 [texte imprimé] / Vincent Ruiz, Auteur ; Eric Meux, Auteur ; Michel Schneider, Auteur . - 2011 . - pp. 5307-5315. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 9 (Mai 2011) . - pp. 5307-5315 Mots-clés : Hydrogen  peroxide  Lixiviation  Oxidation  Catalyst Résumé : This study deals with the feasibility of the oxidative leaching of molybdenum and cobalt sulphides contained in a spent hydrodesulphurisation catalyst using H2O2 in acidic medium. The study was first carried out with MoS2 in order to define the important parameters of the leaching procedure and then applied to an unroasted CoMo/Al2O spent catalyst containing 11 wt % of Mo and 2.7 wt % of Co. In both cases, a 23 factorial design was used. The results obtained with MoS2 highlighted the necessity to limit the increase in temperature of the medium to minimize the decomposition of H2O2 and the necessity to keep pH constant to avoid an important acidification of the medium which could cause dissolution of alumina matrix when leaching will be applied to spent catalysts. The oxidative leaching of the unroasted CoMo/Al2O3 spent catalyst was performed without previous grinding. In a single-step, at pH = 1.3 with a stoichiometric factor equal to 2.4, an L/S ratio equal to 7.5, and an H2O2 concentration of 3.75 mol·L―1, it was possible to recover molybdenum and cobalt simultaneously with leaching yields of 90% and 83%, respectively, without dissolving more than 8% Al. In these conditions, the maximal temperature recorded during the experiment was about 60 °C. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24128652