Process Optimization and Mechanism Study on HCl-NaCl Leaching of Molybdenum-Bismuth Mixed Concentrate AITranslate

Basic Information:

DOI：

Chinese Library Classification Number:TF803.21[冶金工程]

Citation Information:

To address the issues of prolonged flowsheet,high costs,and inter-containment of concentrates in traditional molybdenum-bismuth mixed concentrate beneficiation process,the HCl-NaCl system was employed to leach bismuth from molybdenum-bismuth mixed concentrate to realize the separation of molybdenum and bismuth,and a thermodynamic analysis was performed on the leaching process.The influences of hydrochloric acid concentration,leaching temperature,leaching time,liquid-solid ratio,and NaCl concentration on the leaching rate of bismuth were investigated.The reaction kinetics were analyzed using leaching experimental data to identify the reaction rate-controlling step.The results show that the forms of Bi and S are BiCl₄^-and H₂S,respectively after the reaction of bismuth sulfide with hydrochloric acid without oxidant addition.The factors affecting bismuth leaching rate follow this order of significance:leaching temperature>hydrochloric acid concentration>liquid-solid ratio>NaCl concentration>leaching time.Under the optimized conditions of HCl concentration of 4 mol/L,liquid-solid ratio of 2.0,reaction temperature of 90℃,leaching time of 8 h,and NaCl concentration of 4 mol/L,the average bismuth leaching rate reaches 97.90%.The apparent activation energy of the leaching reaction is 84.55 kJ/mol,indicating an interface chemical reaction control mechanism,and elevated temperature promotes bismuth leaching.