Study On Recovery Of Rhenium(?) From Acidic Wastewater Produced In Copper Metallurgy By Ion Exchange

Ion exchange was selected to extract rhenium from sulfuric acid media due to its characteristics,such as environment friendly,energy-saving and highly efficient.Macroporous weakly basic anion resin ZJ515 is selected as the exchanger.Batch experiments in simulated rhenium-containing sulfuric acid solution and column experiments in real waste sulfuric acid were conducted,which demonstrated the feasibility of ion exchange method.The research contents and results are as follows.The dynamics and thermodynamics studies of adsorption process showed that the adsorption mass transfer process of ZJ515 follows the pseudo-second order kinetic model and is controlled by both particle diffusion and liquid film diffusion.The adsorption process is exothermic and spontaneous.At the temperature of 298.15K,?H =-20.26 kJ·mol-1,AG =-12.74 kJ·mol-1,?S=-25.44 J·k-1·mol-1.Adsorption isotherm is well represented by both Langmuir and Freundlich isotherm models,and the static saturation capacity is 219.78 mg·g-1.The adsorption mechanism of perrhenate on ZJ515 was determined by Fourier Transform Infrared Spectrometry(FTIR).In batch adsorption experiments,the effects of time,the coexisting anions,temperature,acidity and the dosage of resin on the rhenium adsorption ability were investigated.The rhenium concentration reduced intensely to half of the initial concentration after 100 min,and finally reached equilibrium after 72 h.The coexisting anion NO3-,Cl-,F-and S042-would affect the adsorption of ReO4-.High temperature and high acidity would also inhibit the adsorption.The optimum solid liquid ratio of resin in solution was 8 mg·l-1.In addition,the optimum elution condition was 5 M ammonia solution and temperature of 40 0C.In column experiments,the effects of flow rate,temperature,ratio of height to diameter and initial concentration on dynamic adsorption curve,as well as the effects of flow rate,temperature,concentration of eluting agent on dynamic desorption curve were investigated.The dynamic adsorption process follows Thomas model and the dynamic equilibrium capacity is 45.86 mg·g-1 at the temperature of 298.15K.The optimum dynamic adsorption and desorption operation conditions were determined finally.For dynamic adsorption,the optimum condition is flow rate 3 BV/h,ratio of column height to diameter 6:1 and under low temperature.For dynamic desorption,the optimum condition is flow rate 3 BV·h-1,ammonium concentration 4?5 M and temperature 40 ?.