工程科学学报 (Oct 2019)

Activation effect of Pb2+ in cassiterite flotation with styrene phosphonic acid as collector

  • LI Yan-jun,
  • LIU Chang,
  • LIU Jie,
  • GONG Gui-chen

DOI
https://doi.org/10.13374/j.issn2095-9389.2018.09.04.003
Journal volume & issue
Vol. 41, no. 10
pp. 1274 – 1279

Abstract

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Metal ions have a very important influence on the flotation process of minerals, and some of them can activate minerals and thus yield an improvement in the flotation effect. Some production practices have shown that Pb2+ has an activation effect in the process of cassiterite flotation, which can improve the rate of cassiterite recovery. Styrene phosphonic acid is the most commonly used collector in the production of cassiterite flotation. In this study, the activation effect of Pb2+ in cassiterite flotation when styrene phosphonic acid is used as a collector is revealed by single mineral flotation tests. The activation mechanism of Pb2+ in the process of styrene phosphonic acid collecting cassiterite is assessed by contact angle measurement, zeta potential determination, IR spectroscopy, and solution chemistry analysis. The results of single mineral flotation tests indicate that Pb2+ can increase the floatability of cassiterite when the pH is 2.0~8.0, and at a pH of 4.0, the recovery rate of cassiterite reaches maximum, 93.78%, which is 5.33% higher than the recovery rate without Pb2+. The results of zeta potential determination, IR spectroscopy, and solution chemistry analysis show that the styrene phosphonic acid can be adsorbed on the cassiterite surface in form of chemical adsorption, causing the zeta potential of the surface to shift toward the negative direction, and the Pb2+ can promote the adsorption of styrene phosphonic acid on the cassiterite surface, making the zeta potential of the surface lower. Moreover, the Sn4+ on the cassiterite surface can be replaced with Pb2+ and the hydrolyzed species PbOH+ in solutions can interact with Sn-OH on the surface to form the surface complex Sn-O-Pb+, which may lead to an increase in the number of active sites on the cassiterite surface, promoting the adsorption of styrene phosphonic acid on the cassiterite surface and resulting in the activation of cassiterite.

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