Documents disponibles écrits par cet auteur

Bulk flotation of auriferous pyrite and arsenopyrite by using tertiary dodecyl mercaptan as collector in weak alkaline pulp / Jianhua Chen in Minerals engineering, Vol. 23 N° 11-13 (Octobre 2010) 

Public ISBD [article]  in Minerals engineering > Vol. 23 N° 11-13 (Octobre 2010) . - pp. 1070–1072 Titre : Bulk flotation of auriferous pyrite and arsenopyrite by using tertiary dodecyl mercaptan as collector in weak alkaline pulp Type de document : texte imprimé Auteurs : Jianhua Chen, Auteur ; Ye Chen, Auteur ; Zongwu Wei, Auteur Année de publication : 2011 Article en page(s) : pp. 1070–1072 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Gold  ores  Flotation  collectors  Froth  flotation  Sulphide  ores Résumé : Laboratory and industrial scale experiments were conducted to investigate the effect of tertiary dodecyl mercaptan (TDM) as a collector on the flotation of auriferous pyrite and arsenopyrite. The optimum recovery of gold associated with auriferous sulphides was obtained by adding a mixture of TDM and sodium butyl xanthate, together with only a little CuSO4 as an activator in a weak alkaline pulp adjusted by NaOH. A two-month industrial trial at the Liumei plant in Guangxi, China showed that an average gold recovery of 90.8% into a concentrate assaying 81.1 g/t Au from a feed assaying 2.9 g/t Au could be achieved at pH 8–8.5 using TDM as a collector. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687510001755 [article] Bulk flotation of auriferous pyrite and arsenopyrite by using tertiary dodecyl mercaptan as collector in weak alkaline pulp [texte imprimé] / Jianhua Chen, Auteur ; Ye Chen, Auteur ; Zongwu Wei, Auteur . - 2011 . - pp. 1070–1072. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 23 N° 11-13 (Octobre 2010) . - pp. 1070–1072 Mots-clés : Gold  ores  Flotation  collectors  Froth  flotation  Sulphide  ores Résumé : Laboratory and industrial scale experiments were conducted to investigate the effect of tertiary dodecyl mercaptan (TDM) as a collector on the flotation of auriferous pyrite and arsenopyrite. The optimum recovery of gold associated with auriferous sulphides was obtained by adding a mixture of TDM and sodium butyl xanthate, together with only a little CuSO4 as an activator in a weak alkaline pulp adjusted by NaOH. A two-month industrial trial at the Liumei plant in Guangxi, China showed that an average gold recovery of 90.8% into a concentrate assaying 81.1 g/t Au from a feed assaying 2.9 g/t Au could be achieved at pH 8–8.5 using TDM as a collector. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687510001755

A DFT study on the effect of lattice impurities on the electronic structures and floatability of sphalerite / Ye Chen in Minerals engineering, Vol. 23 N° 14 (Novembre 2010) 

Public ISBD [article]  in Minerals engineering > Vol. 23 N° 14 (Novembre 2010) . - pp. 1120–1130 Titre : A DFT study on the effect of lattice impurities on the electronic structures and floatability of sphalerite Type de document : texte imprimé Auteurs : Ye Chen, Auteur ; Jianhua Chen, Auteur ; Jin Guo, Auteur Année de publication : 2011 Article en page(s) : pp. 1120–1130 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Sulfide  ores  Froth  flotation  Simulation Résumé : The electronic structures of bulk sphalerite containing 14 typical kinds of impurities were studied by density-functional theory (DFT). The calculated results show that the presence of Cd, Hg, Ga, Ge, In, Ag, Sn, Pb and Sb could increase the lattice parameter of sphalerite. Ag, Sn, Pb, Sb, Cd and Hg impurities narrowed the band-gap and increased the conductivity of sphalerite. Moreover, Mn, Fe, Ga, In, Sn and Sb impurities changed the semiconductor type of sphalerite from p-type to n-type. All of the impurities except Cd and Hg made the Fermi level shift to higher energy and led to the occurrence of an impurity state in the forbidden band. Analysis of the frontier molecular orbital showed that the impurities Mn, Fe, Cu, Ge, Sn, Pb and Sb contributed greatly to the highest occupied molecular orbital (HOMO) and greatly influence the nucleophilicity of sphalerite. On the other hand, the impurities of Fe, Cu, Co, Ni, Cd and Ga greatly contributed to the lowest unoccupied molecular orbital (LUMO) and greatly affected the electrophilicity of sphalerite. The interactions of O2 and xanthate with sphalerite are discussed. Results suggest that Mn, Fe, Ni, Cu, Sn and Pb impurities favored the oxidization of sphalerite; however, the impurities of Cd, Hg, Ga and In had the opposite effect. Impurities of Mn, Fe, Co, Ni, Cu, Hg and Pb could enhance the reactivity of xanthate with sphalerite. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687510001743 [article] A DFT study on the effect of lattice impurities on the electronic structures and floatability of sphalerite [texte imprimé] / Ye Chen, Auteur ; Jianhua Chen, Auteur ; Jin Guo, Auteur . - 2011 . - pp. 1120–1130. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 23 N° 14 (Novembre 2010) . - pp. 1120–1130 Mots-clés : Sulfide  ores  Froth  flotation  Simulation Résumé : The electronic structures of bulk sphalerite containing 14 typical kinds of impurities were studied by density-functional theory (DFT). The calculated results show that the presence of Cd, Hg, Ga, Ge, In, Ag, Sn, Pb and Sb could increase the lattice parameter of sphalerite. Ag, Sn, Pb, Sb, Cd and Hg impurities narrowed the band-gap and increased the conductivity of sphalerite. Moreover, Mn, Fe, Ga, In, Sn and Sb impurities changed the semiconductor type of sphalerite from p-type to n-type. All of the impurities except Cd and Hg made the Fermi level shift to higher energy and led to the occurrence of an impurity state in the forbidden band. Analysis of the frontier molecular orbital showed that the impurities Mn, Fe, Cu, Ge, Sn, Pb and Sb contributed greatly to the highest occupied molecular orbital (HOMO) and greatly influence the nucleophilicity of sphalerite. On the other hand, the impurities of Fe, Cu, Co, Ni, Cd and Ga greatly contributed to the lowest unoccupied molecular orbital (LUMO) and greatly affected the electrophilicity of sphalerite. The interactions of O2 and xanthate with sphalerite are discussed. Results suggest that Mn, Fe, Ni, Cu, Sn and Pb impurities favored the oxidization of sphalerite; however, the impurities of Cd, Hg, Ga and In had the opposite effect. Impurities of Mn, Fe, Co, Ni, Cu, Hg and Pb could enhance the reactivity of xanthate with sphalerite. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687510001743

The first-principle study of the effect of lattice impurity on adsorption of CN on sphalerite surface / Ye Chen in Minerals engineering, Vol. 23 N° 9 (Août 2010) 

Public ISBD [article]  in Minerals engineering > Vol. 23 N° 9 (Août 2010) . - pp. 676–684 Titre : The first-principle study of the effect of lattice impurity on adsorption of CN on sphalerite surface Type de document : texte imprimé Auteurs : Ye Chen, Auteur ; Jianhua Chen, Auteur Année de publication : 2011 Article en page(s) : pp. 676–684 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Sulphide  ores  Froth  flotation  Simulation Résumé : The adsorption of CN on sphalerite (1 1 0) surface and the effects of lattice impurities on the surface adsorption have been investigated using density-functional theory (DFT). The results show that CN adsorbs strongly on perfect sphalerite (1 1 0) surface, where C atom and N atom of CN molecule are bonding with two Zn atoms on the surface. The presence of Fe/Mn/Cu-impurity on sphalerite surface was shown to enhance the CN adsorption, however; Cd impurity worked in the opposite. The adsorption mode of CN on defective surfaces is mainly via C atom interacting with the impurity atom, and s orbital of C interacts with sp orbital of Fe/Mn/Cu to form the covalent bond, and d orbital of Fe/Mn/Cu donates electrons to the anti-bonding p orbital of C to form the back donating π bonding. While on the Cd-bearing surface, Cd 4d orbital donates fewer electrons to the vacant View the MathML source of C, and thus no back donating π bonding appears and the adsorption of CN on Cd-bearing sphalerite surface is weak. The simulations of CN adsorption show that Fe-bearing sphalerite could be easily depressed by cyanide, while Cd-bearing sphalerite is difficult to be depressed by cyanide. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S089268751000110X [article] The first-principle study of the effect of lattice impurity on adsorption of CN on sphalerite surface [texte imprimé] / Ye Chen, Auteur ; Jianhua Chen, Auteur . - 2011 . - pp. 676–684. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 23 N° 9 (Août 2010) . - pp. 676–684 Mots-clés : Sulphide  ores  Froth  flotation  Simulation Résumé : The adsorption of CN on sphalerite (1 1 0) surface and the effects of lattice impurities on the surface adsorption have been investigated using density-functional theory (DFT). The results show that CN adsorbs strongly on perfect sphalerite (1 1 0) surface, where C atom and N atom of CN molecule are bonding with two Zn atoms on the surface. The presence of Fe/Mn/Cu-impurity on sphalerite surface was shown to enhance the CN adsorption, however; Cd impurity worked in the opposite. The adsorption mode of CN on defective surfaces is mainly via C atom interacting with the impurity atom, and s orbital of C interacts with sp orbital of Fe/Mn/Cu to form the covalent bond, and d orbital of Fe/Mn/Cu donates electrons to the anti-bonding p orbital of C to form the back donating π bonding. While on the Cd-bearing surface, Cd 4d orbital donates fewer electrons to the vacant View the MathML source of C, and thus no back donating π bonding appears and the adsorption of CN on Cd-bearing sphalerite surface is weak. The simulations of CN adsorption show that Fe-bearing sphalerite could be easily depressed by cyanide, while Cd-bearing sphalerite is difficult to be depressed by cyanide. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S089268751000110X