The Influence of Branched Chain Length on Different Causticized Starches for the Depression of Serpentine in the Flotation of Pentlandite

Abstract

Although studies on starch have developed in polymer chemistry research, their structure-activity relationship remains indistinct in the flotation depressants field. In this work, the utilization of five types of causticized starches from different botanical sources as depressants in the flotation of pentlandite/serpentine pure mineral systems was studied. The branched chain length of the starches was quantitatively analyzed using a high-performance anion-exchange chromatography system, and the average branched chain lengths of the causticized starches were obtained. The flotation results demonstrated that the depression effect of all causticized starches on serpentine had a positive correlation with the average branched chain length. Zeta potential tests, FTIR experiments, and XPS analysis confirmed that the causticized starches with a longer branched chain were absorbed more strongly on the serpentine surface. In the present study, the influence of branched chain length on the depression effect of causticized starch was investigated, which deepened our understanding of the depression mechanism of traditional macromolecule depressants and will promote the development of new macromolecule depressants.