Abstract: Iodine leaching,as an environmentally friendly non-cyanide gold extraction process,is limited in industrial application
by the high consumption and cost of iodide reagents. Therefore,efficient recycling of iodine from the lean solution of iodine
leaching is key to reducing production costs. In this study,a simulated lean solution with an I2 concentration of 8. 128
g/ L and an I2 to I- molar ratio of 1∶6 was used as the research object. Ozone oxidation was employed to recover iodide ions,
and the effects of pH,ozone concentration,ozone flow rate,and oxidation time on the iodide ion recovery rate were systematically
investigated. The interactions among these factors were analyzed using response surface methodology. The results indicate
that strongly acidic conditions (pH=2) favor the oxidation of iodide ions by ozone. The iodide ion recovery rate first increases
and then decreases with increasing ozone concentration and flow rate,while prolonged oxidation time improves recovery. Significant
interactions exist among ozone concentration,flow rate,and oxidation time,which collectively determine the effective amount
of ozone reacting with iodide ions. Through optimization via response surface methodology,the optimal process parameters
were determined as follows:pH=2,ozone concentration 30%,ozone flow rate 1. 1 L/ min,and oxidation time 85 min. Under
these conditions,the iodide ion recovery rate reached 98. 6%,indicating nearly complete recovery. In conclusion,ozone oxidation
can efficiently recover iodine from the lean solution of iodine leaching,providing a new pathway for the recycling of iodide
leaching reagents.