Ultrasound assisted sodium-chlorate leaching of selenium from copper anode slime

This study proposes an environmentally friendly process for recovering selenium from copper anode slime, a resourceful solid waste. Selenium is recovered during exposure to chlorine radicals and ultrasonic waves, which cooperate to stimulate advanced oxidation processes in the wet selenium extraction process. The influences of different experimental parameters on the selenium leaching efficiency were investigated. The ultrasonic selenium leaching efficiency reached 98.2% under the optimum conditions, whereas the deseleniumization efficiency of conventional leaching was only 57.5%. A series of mineral characterization tests proved that the ultrasonic leaching process improved the leaching efficiency by fully breaking the raw ores. The sodium chlorate process with ultrasound is a promising hydrometallurgical approach for the efficient and profitable extraction of a value-added product (selenium) from hazardous waste (copper anode slime).