Documents disponibles écrits par cet auteur

Effect of surfactant OPD on the bioleaching of marmatite / Zhuoyue Lan in Minerals engineering, Vol. 22 N° 1 (Janvier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 1 (Janvier 2009) . - pp. 10–13 Titre : Effect of surfactant OPD on the bioleaching of marmatite Type de document : texte imprimé Auteurs : Zhuoyue Lan, Auteur ; Yuehua Hu, Auteur ; Wenqing Qin, Auteur Année de publication : 2009 Article en page(s) : pp. 10–13 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Bioleaching  Bacteria  Sulphide  ore  Reaction  kinetics  Hydrometallurgy Index. décimale : 622 Industrie minière Résumé : The effect of surfactant o-phenylenediamine (OPD) on the bioleaching of marmatite with mixed cultures of Acidithiobacillusferrooxidans, Acidithiobacillusthiooxidans and Leptospirillumferrooxidans was examined in shaking flasks. The effect of OPD on the iron and sulfur oxidizing capacity of the bacteria was also investigated. Results show that the addition of OPD in low concentration was favorable for the bio-oxidation of elemental sulfur and had little negative effect on that of iron. Chemical analysis and EDX analysis of the leached residues reveal that zinc was selectively leached over iron. The elemental sulfur produced from the leaching reaction was not completely oxidized and dissolved only partially even in the presence of bacteria, which limited the dissolution rate of marmatite. However, the addition of OPD accelerated the oxidation of elemental sulfur in the presence of bacteria, thus enhancing the bioleaching rate of marmatite. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508000502 [article] Effect of surfactant OPD on the bioleaching of marmatite [texte imprimé] / Zhuoyue Lan, Auteur ; Yuehua Hu, Auteur ; Wenqing Qin, Auteur . - 2009 . - pp. 10–13. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 1 (Janvier 2009) . - pp. 10–13 Mots-clés : Bioleaching  Bacteria  Sulphide  ore  Reaction  kinetics  Hydrometallurgy Index. décimale : 622 Industrie minière Résumé : The effect of surfactant o-phenylenediamine (OPD) on the bioleaching of marmatite with mixed cultures of Acidithiobacillusferrooxidans, Acidithiobacillusthiooxidans and Leptospirillumferrooxidans was examined in shaking flasks. The effect of OPD on the iron and sulfur oxidizing capacity of the bacteria was also investigated. Results show that the addition of OPD in low concentration was favorable for the bio-oxidation of elemental sulfur and had little negative effect on that of iron. Chemical analysis and EDX analysis of the leached residues reveal that zinc was selectively leached over iron. The elemental sulfur produced from the leaching reaction was not completely oxidized and dissolved only partially even in the presence of bacteria, which limited the dissolution rate of marmatite. However, the addition of OPD accelerated the oxidation of elemental sulfur in the presence of bacteria, thus enhancing the bioleaching rate of marmatite. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508000502

Flotation and surface behavior of cassiterite with salicylhydroxamic acid / Wenqing Qin in Industrial & engineering chemistry research, Vol. 50 N° 18 (Septembre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 18 (Septembre 2011) . - pp. 10778-10783 Titre : Flotation and surface behavior of cassiterite with salicylhydroxamic acid Type de document : texte imprimé Auteurs : Wenqing Qin, Auteur ; Yangbao Xu, Auteur ; Hui Liu, Auteur Année de publication : 2011 Article en page(s) : pp. 10778-10783 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Flotation Résumé : The flotation and surface interaction of cassiterite with salicylhydroxamic acid have been investigated in this paper. The results showed that recovery of cassiterite with salicylhydroxamic acid was high at a neutral pH, with the maximum recovery occurring at ca. pH 6.5. When the size of cassiterite is less than 74 μm, coarse particles showed better flotability than the fine ones. The adsorption of salicylhydroxamic acid was also high at a neutral pH. The isoelectric point of cassiterite showed an acidic shift in the presence of salicylhydroxamic acid. A chelate was identified on the cassiterite surface. The results of the adsorption, electrophoretic mobility, and IR spectrum of cassiterite indicated that the adsorption on the cassiterite surface included both physical and chemical adsorption. On the basis of the experimental results, a complex multilayer adsorption model was proposed to illustrate the adsorption on the surface of cassiterite. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24523894 [article] Flotation and surface behavior of cassiterite with salicylhydroxamic acid [texte imprimé] / Wenqing Qin, Auteur ; Yangbao Xu, Auteur ; Hui Liu, Auteur . - 2011 . - pp. 10778-10783. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 18 (Septembre 2011) . - pp. 10778-10783 Mots-clés : Flotation Résumé : The flotation and surface interaction of cassiterite with salicylhydroxamic acid have been investigated in this paper. The results showed that recovery of cassiterite with salicylhydroxamic acid was high at a neutral pH, with the maximum recovery occurring at ca. pH 6.5. When the size of cassiterite is less than 74 μm, coarse particles showed better flotability than the fine ones. The adsorption of salicylhydroxamic acid was also high at a neutral pH. The isoelectric point of cassiterite showed an acidic shift in the presence of salicylhydroxamic acid. A chelate was identified on the cassiterite surface. The results of the adsorption, electrophoretic mobility, and IR spectrum of cassiterite indicated that the adsorption on the cassiterite surface included both physical and chemical adsorption. On the basis of the experimental results, a complex multilayer adsorption model was proposed to illustrate the adsorption on the surface of cassiterite. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24523894

Purification of leachate from simultaneous leaching of galena concentrate and pyrolusite and preparation of PbSO4 and Mn3O4 / Wenqing Qin in Industrial & engineering chemistry research, Vol. 51 N° 15 (Avril 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 15 (Avril 2012) . - pp 5596–5607 Titre : Purification of leachate from simultaneous leaching of galena concentrate and pyrolusite and preparation of PbSO4 and Mn3O4 Type de document : texte imprimé Auteurs : Wenqing Qin, Auteur ; Fen Jiao, Auteur ; Benjun Xu, Auteur Année de publication : 2012 Article en page(s) : pp 5596–5607 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Leachate  Pyrolusite Résumé : This paper presents the results of investigation on simultaneous leaching of galena concentrate and pyrolusite in acid medium. It has been confirmed that the leached products as the raw materials—PbCl2, MnCl2 for the PbSO4 and Mn3O4 preparations could be obtained during the leaching processes. Special emphasizes are placed on the purification of the simultaneous leaching solution including removals of Fe2+, Pb2+, Zn2+, Ca2+, and preparations. The factors affecting the purification, such as pH, temperature, agitation rate, and dosages of Cl– and Na2S are investigated in leaching cells. The results show that, at appropriate conditions, iron is removed in the form of FeOOH, Pb2+ and Zn2+ are vulcanized by Na2S, and Ca2+ is removed in the form of CaF2 precipitation. After purification and crystallizing-out of PbCl2 (97.17%), the effects of pH, temperature, reaction time, concentration, stirring rate, and drying methods on preparations are examined. The mechanisms are addressed by theoretical calculations and experiments. The results indicate that the content of PbSO4 is 99.46% characterized by elemental analysis, XRD, and SEM. The purity of Mn3O4 is identified by TG-DSC, chemical analysis, and XRD, and the Mn in the Mn3O4 product accounts for 71.7%. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2024678 [article] Purification of leachate from simultaneous leaching of galena concentrate and pyrolusite and preparation of PbSO4 and Mn3O4 [texte imprimé] / Wenqing Qin, Auteur ; Fen Jiao, Auteur ; Benjun Xu, Auteur . - 2012 . - pp 5596–5607. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 15 (Avril 2012) . - pp 5596–5607 Mots-clés : Leachate  Pyrolusite Résumé : This paper presents the results of investigation on simultaneous leaching of galena concentrate and pyrolusite in acid medium. It has been confirmed that the leached products as the raw materials—PbCl2, MnCl2 for the PbSO4 and Mn3O4 preparations could be obtained during the leaching processes. Special emphasizes are placed on the purification of the simultaneous leaching solution including removals of Fe2+, Pb2+, Zn2+, Ca2+, and preparations. The factors affecting the purification, such as pH, temperature, agitation rate, and dosages of Cl– and Na2S are investigated in leaching cells. The results show that, at appropriate conditions, iron is removed in the form of FeOOH, Pb2+ and Zn2+ are vulcanized by Na2S, and Ca2+ is removed in the form of CaF2 precipitation. After purification and crystallizing-out of PbCl2 (97.17%), the effects of pH, temperature, reaction time, concentration, stirring rate, and drying methods on preparations are examined. The mechanisms are addressed by theoretical calculations and experiments. The results indicate that the content of PbSO4 is 99.46% characterized by elemental analysis, XRD, and SEM. The purity of Mn3O4 is identified by TG-DSC, chemical analysis, and XRD, and the Mn in the Mn3O4 product accounts for 71.7%. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2024678

Selective flotation of chalcopyrite and marmatite by MBT and electrochemical analysis / Wenqing Qin in Industrial & engineering chemistry research, Vol. 51 N° 35 (Septembre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 35 (Septembre 2012) . - pp. 11538-11546 Titre : Selective flotation of chalcopyrite and marmatite by MBT and electrochemical analysis Type de document : texte imprimé Auteurs : Wenqing Qin, Auteur ; Fen Jiao, Auteur ; Wei Sun, Auteur Année de publication : 2012 Article en page(s) : pp. 11538-11546 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Flotation Résumé : Various collectors were compared in the selective flotation of copper-zinc ore by using isopropyl ethylthionocarbamate (Z-200), buthl xanthate, ammonium dibutyl dithiophosphate, and mercapto benzothiazole (MBT). The latter showed effective selectivity in the flotation of chalcopyrite and marmatite and was selected for a detailed study by using cyclic voltammetry and Tafel. The results of microflotation pointed out that the flotation of marmatite was significantly affected by CuSO4 activation. At weakly alkaline pH, marmatite activated by Cu2+ is dependent on Cu2+ concentration shown in electrochemical tests, and the activation products were Cu2S and CuS. The increasing addition of Cu2+ may remove the hydroxide and S0, resulting in considerable activation. The corrosion of marmatite is accelerated with the addition of CuSO4. Mechanisms are suggested for the selectivity of chalcopyrite/marmatite by MBT: the hydrophilic hydroxides (Zn(OH)2 and Fe(OH)3) are formed on the marmatite surface, which renders the marmatite surface hydrophilic and hampers the reaction between MBT and marmatite-activated products, while the hydrophobic compounds (MBT)2 and Cu(MBT)2 formed on the chalcopyrite surface improve the flotability of chalcopyrite. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26324803 [article] Selective flotation of chalcopyrite and marmatite by MBT and electrochemical analysis [texte imprimé] / Wenqing Qin, Auteur ; Fen Jiao, Auteur ; Wei Sun, Auteur . - 2012 . - pp. 11538-11546. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 35 (Septembre 2012) . - pp. 11538-11546 Mots-clés : Flotation Résumé : Various collectors were compared in the selective flotation of copper-zinc ore by using isopropyl ethylthionocarbamate (Z-200), buthl xanthate, ammonium dibutyl dithiophosphate, and mercapto benzothiazole (MBT). The latter showed effective selectivity in the flotation of chalcopyrite and marmatite and was selected for a detailed study by using cyclic voltammetry and Tafel. The results of microflotation pointed out that the flotation of marmatite was significantly affected by CuSO4 activation. At weakly alkaline pH, marmatite activated by Cu2+ is dependent on Cu2+ concentration shown in electrochemical tests, and the activation products were Cu2S and CuS. The increasing addition of Cu2+ may remove the hydroxide and S0, resulting in considerable activation. The corrosion of marmatite is accelerated with the addition of CuSO4. Mechanisms are suggested for the selectivity of chalcopyrite/marmatite by MBT: the hydrophilic hydroxides (Zn(OH)2 and Fe(OH)3) are formed on the marmatite surface, which renders the marmatite surface hydrophilic and hampers the reaction between MBT and marmatite-activated products, while the hydrophobic compounds (MBT)2 and Cu(MBT)2 formed on the chalcopyrite surface improve the flotability of chalcopyrite. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26324803