Kinetic studies of gold leaching from a gold concentrate calcine by thiosulfate with cobalt-ammonia catalysis and gold recovery by resin adsorption from its pregnant solution

摘要: Abstract The leaching of gold from a concentrate calcine using novel thiosulfate method that utilizes cobalt-ammonia complex as the oxidant in place traditional copper-ammonia catalysis was investigated. result shows consumption can be evidently reduced without impact on extraction. kinetics solution with has been studied. It found reaction orders respect to ammonia, cobalt and concentrations are 0.42, 0.20 0.34, respectively. optimal pH value for is 10.0, effectively extracted at ambient temperature. apparent activation energy determined 5.68 kJ/mol, this indicates Co-NH3-S2O32− system likely controlled by diffusion reactants products through solid layer. XPS analysis results strongly support hypothesis. energies thiosulfate-only Cu-NH3-S2O32− systems 30.9 kJ/mol 8.01 kJ/mol, concluded higher catalytic efficiency than catalysis. tests recovery pregnant resin adsorption were implemented, demonstrated competitive did not occur owing weak affinity strong base anion ions. Therefore, elution loaded only needs perform simple one-stage process instead two-stage system, which will contribute reduce cost solution.