Publication Details
Abstract
This study investigates the regeneration of spent zinc catalysts containing 71–76% zinc oxide and their conversion into zinc oxide through nitric acid processing. The effects of key technological parameters on zinc recovery were examined. Optimal conditions for zinc extraction were identified as an acid dosage of 120% of the stoichiometric requirement, a nitric acid concentration of 30%, a leaching time of 3 hours, and a temperature of 95°C. The resulting zinc nitrate solution was further processed by precipitation using an 18% sodium carbonate solution at a temperature of 65–70°C and a pH range of 7,9–8,2, with a reaction time of 45 minutes, leading to the formation of zinc hydroxide carbonate. The obtained precipitate was then dried at 120°C for 2 hours and subsequently calcined at 500°C for 5 hours to produce zinc oxide.