Enhancement of copper metal dissolution in sulfuric acid solution with oxygen and ultrasound

Abstract

A new method for copper metal dissolution by simultaneous use of oxygen and ultrasound was proposed to enhance the copper dissolution rate in sulfuric acid (H2SO4). The influence factors such as ultrasonic power, oxygen flow rate, reaction temperature, initial copper ion (Cu2+) and H2SO4 concentration was studied to study the dissolution behaviour of copper metal. The dissolution rate of Cu could reach 7.52 g h−1 L−1 after the ultrasonic strengthening, which is 1.83 times higher than that without ultrasonic irradiation (4.109 g h−1 L−1). The study of leaching kinetics found that the Cu leaching process with and without ultrasound were both controlled by surface chemical reaction. The ultrasound could significantly reduce the apparent activation energy of the leaching reaction from 43.52 kJ mol−1 to 28.40 kJ mol−1. Characteristics revealed that the cavitation effect of ultrasound could increase the specific surface area of copper metal and oxygen bubble, and enhance the oxidizing capability of this leaching system, which is beneficial for the dissolution of Cu. Therefore, ultrasonic-assisted technology has provided novel insights for the hydrometallurgical recovery of copper.

Keywords

• Copper
• Dissolution
• H2SO4
• Oxygen
• Ultrasound