Adsorption mechanism of styryl phosphonate ester as collector in ilmenite flotation
(1. School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan 430070, China;
2. South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510530, China;
3. Engineering Research Center of Phosphorus Resources Development and Utilization of Ministry of Education, Wuhan Institute of Technology, Wuhan 430205, China;
4. Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen 518055, China)
2. South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510530, China;
3. Engineering Research Center of Phosphorus Resources Development and Utilization of Ministry of Education, Wuhan Institute of Technology, Wuhan 430205, China;
4. Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen 518055, China)
Abstract: A styryl phosphonate ester (SPE) collector was used to improve the flotation performance of ilmenite, and the adsorption mechanism and model were revealed and established, respectively. Microflotation tests showed that SPE exhibited a stronger collecting ability for ilmenite than the traditional collector styrene phosphonic acid (SPA). Zeta potential measurements revealed that both SPE and SPA could negatively shift the zeta potential of ilmenite, while SPE had more effects than SPA, suggesting the stronger adsorption of SPE. The analysis of X-ray photoelectron spectroscopy confirmed the chemisorption of SPA and SPE onto the Fe/Ti sites of ilmenite. According to frontier orbital theory, the chemical activities of SPE are greater than those of SPA. The partial densities of states analysis indicated that the PO—H groups of the collectors could interact with the Ti/Fe atoms of the ilmenite surface to generate a stable four-membered ring. The bonding model of the collector and (104) ilmenite surface showed that the adsorption energy of SPE was higher than that of SPA. Overall, SPE presented a better collecting ability and interaction effect for ilmenite flotation than SPA, and had the potential to replace SPA in the industry.
Key words: styryl phosphonate ester; ilmenite; flotation; collector; X-ray photoelectron spectroscopy; density functional theory; adsorption mechanism