| Based on literature review of metal leaching models in current hydrometallurgical fields, with the stability study of the LS(Lime-sulfur-synthetic-solution), ML(Modified LS) and thiosulfate leaching gold systems and the kinetic study of the major lixiviants in the ML and LS leaching gold system respectively, the kinetics models of ML and thiosulfate leaching gold from gold bearing concentrate have been deduced from the unreacted retract model. The prediction results by those kinetic models are well coincident with experimental results. According to the electrochemical-catalytic mechanism of leaching gold by the thiosulfate, the reasonable concentration ratio between the SaO32- oxidation and Cu(NH3)42+ obtained is around 9.6~10.5. Under given conditions, the formulas of the SX2- oxidation, in the polysulfide leaching system and those of S2O32- in the ML and LS leaching gold systems were established respectively. The reaction apparent active energy were calculated under the experimental conditions. It is concluded that the ML and thiosulfate leaching gold system are relatively stable, while those to of LS and polysulfide leaching gold systems are metastable systems. This study is of significance the optimization of the sulfur-bearing reagents leaching gold systems. |
