چكيده به لاتين
In this research, the recovery of valuable metals such as nickel (Ni), cadmium (Cd), copper (Cu) and zinc (Zn) from industrial zinc filter cake has been investigated as a valuable solution for waste management and providing secondary sources of these metals in the industry. After examining and obtaining the effective operational parameters, using the response surface method, the effect of the four effective operational parameters of temperature, time, solid-to-liquid ratio, and pH have been experimentally investigated. Adsorption of Ni, Cd, Cu and Zn on two commercial resins CH030 and CH020 from Canftech Company as a function of pH, temperature, time and solid-to-liquid ratio has been investigated with RSM at five levels. Based on the results obtained from Batch adsorption, it was found that these resins, which have the aminophosphonic acid functional group, adsorb Ni, Cd, Cu and Zn metals effectively from the real acid leaching solution. Response surface modeling was developed using a central composite design (CCD). Statistical criteria of correlation coefficient (R2) values were obtained experimentally for nickel, copper, cadmium and zinc, respectively 0.9418, 0.9753, 0.9657 and 0.9189. The adsorption of nickel, copper, cadmium and zinc followed the pseudo-second-order kinetic model and all thermodynamic and kinetic calculations showed the chemical interaction between the surface of the resin and the ions of Ni, Cd, Cu and Zn. An enthalpy value greater than 0 was obtained for all four metals, which indicates that their adsorption process is endothermic. The optimal adsorption capacity of 13.408, 7.087, 4.357, 15.040 mg/g of nickel, copper, cadmium and zinc in optimal operating conditions of 20 min, 30°C, pH of 5 and 4 g/L was obtained based on the results of RSM. The results showed that at pH greater than 6, metals are precipitated as hydroxides in the solution and cause errors in the analysis of the concentration of metals adsorbed on the resin.
