Influences of starch depressant with the various molecular structure on the interactions between hematite particles and flotation bubbles

The native starches are the carbohydrate polymer consisting of glucose units, which can be used as an efficient depressant in hematite flotation. This study explores the effects of starch with various molecular structures on the hematite flotation via the particle-bubble interaction. Three starches (NS, WS and G50) with different amylose (AM) to amylopectin (AP) ratios were applied to investigate the collision and adhesion behaviors of hematite particles onto a bubble through a homemade observation setup. The results showed that the probability of collision and adhesion increased and decreased separately after adding starches. Contact angle measurement and particle size analysis indicated that starch with higher AP content was more likely to aggregate mineral particles to increase the collision probability, while it is easier to make the hematite surface hydrophilic to reduce the adhesion probability. Furthermore, based on the experimental results and previous theories, a modified Yoon-Luttrell model was proposed to explain the interaction between hematite particles and bubbles, and the role of starch molecular structure in this model was also discussed.

Automated summary

This study investigates the effects of starches with different molecular structures on hematite flotation. The results show that starches with higher amylopectin content can increase the collision probability and hydrophilicity of hematite particles, thereby reducing the adhesion probability.