The molecular structure effects of starches and starch phosphates in the reverse flotation of quartz from hematite

Qianqian Wang; Haofeng Zhang; Yanling Xu; Shenxu Bao; Cheng Liu; Siyuan Yang

doi:10.1016/j.carbpol.2022.120484

The molecular structure effects of starches and starch phosphates in the reverse flotation of quartz from hematite

Carbohydr Polym. 2023 Mar 1:303:120484. doi: 10.1016/j.carbpol.2022.120484. Epub 2022 Dec 21.

Authors

Qianqian Wang¹, Haofeng Zhang¹, Yanling Xu¹, Shenxu Bao¹, Cheng Liu¹, Siyuan Yang²

Affiliations

¹ School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan 430070, China.
² School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan 430070, China; State Key Laboratory of Mineral Processing, BGRIMM Technology Group, Beijing 102600, China. Electronic address: siyuan.yang@whut.edu.cn.

PMID: 36657853
DOI: 10.1016/j.carbpol.2022.120484

Abstract

Native starches and their phosphates with various molecular structures was introduced as the depressant to realize the flotation of quartz from hematite in this study. The present starch phosphates (WSP, NSP, GSP) were modified by the reaction between phosphate and three different corn starches (WS, NS, G50). The synthesis and characterization of starch phosphates found that starch with high amylopectin content was easily modified into starch phosphates. Microflotation tests showed that starch phosphates exhibited stronger depressing abilities of hematite flotation than native starches. Zeta potential measurement showed that both starches and starch phosphates could positively shift the zeta potential of hematite, while starch phosphates had more effects than starches. XPS and MDS indicated that the chemisorption occurred between Fe of hematite surface and CO groups of starch-based depressants. In addition, starch phosphates could adsorb onto the hematite surface through PO groups. MDS also presented that the adsorption strength of starch phosphate was mainly determined by the type and number of generating chelating rings, and the molecular structure of starch significantly affected the formation of chelate rings. The proposed adsorption model insights will significantly promote the development of starch-based depressants for iron ore flotation and other mineral processing applications.

Keywords: Flotation; Hematite; MDS; Quartz; Starch phosphate; XPS.