Ultrasound-enhanced ilmenite acid leaching and optimization research

• Published in: Physicochemical problems of mineral processing
• Main Authors: Xiang, Long, Long, Tao, Liu, Jie Song, Li, Li, Xiang, Wen Rong, Zhang, Xing Ran, Zhang, Yong
• Format: Journal Article
• Language: English
• Published: 31.07.2025
• ISSN: 1643-1049; 2084-4735
• DOI: 10.37190/ppmp/208752

In the production of titanium dioxide pigment via the sulfuric acid process, maintaining a high sulfuric acid concentration (85%) is essential for efficient titanium leaching. However, this conventional approach generates substantial waste acid (20% sulfuric acid). By reducing the reactive sulfuric acid concentration, the waste acid recycling rate can be increased, thereby decreasing waste acid production and conserving fresh sulfuric acid consumption. In this paper, ultrasonic activation is employed to enhance the premixing process of ilmenite. The effects of sulfuric acid concentration, ultrasonic power, and ultrasonic time on the ilmenite leaching rate were studied using an L9 (33) orthogonal test. In order of significance, the primary factors influencing the ilmenite leaching rate are sulfuric acid concentration, ultrasonic power, and ultrasonic time. The optimal conditions for ilmenite leaching are as follows: a sulfuric acid concentration of 80%, an ultrasonic power of 800 W, and an ultrasonic time of 5 min. Under these conditions, the ilmenite leaching rate can reach 93.07%. Ultrasonic cavitation can reduce the size of ilmenite while increasing its surface area and surface reactivity. Furthermore, the ultrasonic strengthening effect can enhance the porosity of the reactive solid phase, promote the diffusion of sulfuric acid on the surface of the ilmenite, and improve the acid hydrolysis rate of ilmenite concentrate at low concentrations.