Leaching kinetics of enargite in alkaline sodium sulphide solutions

摘要: Abstract Leaching of enargite samples containing approximately 12% As, 0.5% Sb and 39% Cu was studied in alkaline sulphide solutions sodium hydroxide sulphide. Kinetic parameters included temperature, particle size, reagent concentration, agitation rate stoichiometry high pulp density experiments. The extraction arsenic chemical reaction controlled with an activation energy 74 kJ mol− 1, indicating the importance temperature on process. relative contributions total initial concentrations leaching kinetics were determined a new equation developed r As = − d dt k ' 2.37 S 2 1.83 OH 3.31 , kg t 1 h where k′ depends system can be predicted from this parameter (it had value 1.63 × 10− 3 work). This validated against data presented other similar studies leaching. It is demonstrated that ion plays direct role reaction, rather than simply ensuring adequate speciation. Copper, iron, zinc, silver not extracted during procedure. Through analysis, X-ray diffraction scanning electron microscopy leach residues characterised. Residues contained copper–sulphur compounds such as digenite, bornite copper (NaCu5S3).