Selective leaching of arsenic from enargite in NaHS–NaOH media

Abstract The dissolution kinetics of arsenic from enargite (Cu 3 AsS 4 ) was investigated in sodium hydrosulfide (NaHS) solution of concentration range 0.68 M–1.35 M S 2− and 1.25 M OH − (NaOH) in the temperature range from 298 K to 363 K. The kinetic equation from evaluation of experimental data using several heterogeneous and pseudo-homogeneous reaction models was found to be 1−3(1− α ) 2/3 + 2(1− α ) =  kt and from the Arrhenius plot, using k values determined experimentally, an activation energy of 70.26 ± 4.74 kJ/mol was obtained. This result indicates that the rate-determining process for the reaction between Cu 3 AsS 4 and NaHS is controlled by product layer diffusion process. Characterization of solid samples by XRD and chemical analysis by ICP showed that Cu 3 AsS 4 was transformed to Cu 2 S and complete removal of arsenic into solution can be achieved within 60 to 120 min.

[1]  T. Pauporté,et al.  An electrochemical study of natural enargite under conditions relating to those used in flotation of sulphide minerals , 1996 .

[2]  A. Roca,et al.  Topochemical transformation of enargite into copper oxide by hypochlorite leaching , 2003 .

[3]  Cetin Kantar.  Solution and flotation chemistry of enargite , 2002 .

[4]  M. C. Ruiz,et al.  Leaching of enargite in H2SO4–NaCl–O2 media , 2005 .

[5]  Dimitrios Filippou,et al.  RECOVERY OF METAL VALUES FROM COPPER—ARSENIC MINERALS AND OTHER RELATED RESOURCES , 2007 .

[6]  R. Macdonald,et al.  The kinetics of dissolution of enargite in acidified ferric sulphate solutions , 1972 .

[7]  Warren J. Bruckard,et al.  The selective flotation of enargite from other copper minerals — a single mineral study in relation to beneficiation of the Tampakan deposit in the Philippines , 2006 .

[8]  M. Ghiani,et al.  Beneficiation of a gold bearing enargite ore by flotation and As leaching with Na-hypochlorite , 2005 .

[9]  John Ralston,et al.  Separation of enargite and tennantite from non-arsenic copper sulfide minerals by selective oxidation or dissolution , 2001 .

[10]  A. Rossi,et al.  Enargite oxidation: A review , 2008 .

[11]  P. Baláž,et al.  Influence of mechanical activation on the alkaline leaching of enargite concentrate , 2000 .

[12]  M. C. Hernández,et al.  Dissolution kinetics of enargite in dilute Cl2/Cl− media , 2002 .

[13]  Ivan Mihajlović,et al.  A potential method for arsenic removal from copper concentrates , 2007 .

[14]  P. Baláž,et al.  Mechano-chemical leaching in hydrometallurgy of complex sulphides , 2006 .

[15]  E. Jackson,et al.  Hydrometallurgical extraction and reclamation , 1986 .

[16]  M. Ferrini,et al.  Arsenic leaching by Na2S to decontaminate tailings coming from colemanite processing , 2003 .

[17]  N. Welham.  Mechanochemical processing of enargite (Cu3AsS4) , 2001 .

[18]  M. Ghiani,et al.  Arsenic leaching from a gold bearing enargite flotation concentrate , 2009 .

[19]  J. C. Gentina,et al.  Laboratory-scale continuous bio-oxidation of a gold concentrate of high pyrite and enargite content , 2002 .

[20]  A. Shibayama,et al.  Arsenic removal from copper ores and concentrates through alkaline leaching in NaHS media , 2009 .

[21]  W. Yen,et al.  Selective flotation of enargite from chalcopyrite by electrochemical control , 2005 .

[22]  P. Baláž,et al.  Selective leaching of antimony and arsenic from mechanically activated tetrahedrite, jamesonite and enargite , 2006 .