Aggregation process of fine hematite particles suspension using xanthan gum in the presence of Fe(III)

Abstract

Aggregation is an economical and widely existing method to in hematite mineral processing. In order to achieve the aggregation of hematite particles, high-efficiency agents are required. In this work, the xanthan gum (XG) and Fe3+ were used to explore its aggregation effect on the fine hematite particles. The settling and adsorption experiments were conducted on hematite with XG in the absence and presence of Fe3+. The results show that it is difficult to settle hematite with XG alone, and XG exhibits excellent performance with the mass ratio of 2/1 (XG/ FeCl3) at pH 2–10 in the presence of Fe3+. Zeta potential measurements, Fourier transform infrared (FTIR), Microscope and X-ray photoelectron spectroscopy (XPS) analyses were performed to detect the underlying mechanism. The zeta potential, solution chemistry and FTIR analyses results show that the co-adsorption of XG, Fe(OH)2+, Fe(OH)2+ and Fe3+ is found on hematite surface through specific and electrostatic adsorption, respectively, and the hematite surface is also covered by Fe(OH)3(s) precipitation turned by Fe3+. XPS spectral investigations and microscope observations provide evidence in support of coordination interaction between ferric ions active sites and XG. In addition, the aggregation model of fine hematite particles suspension using XG in the presence of Fe3+ was drawn.