XPS study on the mechanism of starch-hematite surface chemical complexation. (15th August 2017)

• Record Type: Journal Article
• Authors: Moreira, Gabriela F.; Peçanha, Elaynne R.; Monte, Marisa B.M.; Leal Filho, Laurindo S.; Stavale, Fernando
• Is Part Of: Minerals engineering. Volume 110(2017)
• Page Start: 96
• Page End: 103
• Publication Date: 2017-08-15
• Subjects: Iron ore -- Starch -- Flotation -- XPS -- FTIR; Mines and mineral resources -- Periodicals; Ressources minérales -- Périodiques; Mines and mineral resources; Periodicals; Electronic journals; 622
• DOI: 10.1016/j.mineng.2017.04.014
• Languages: English
• ISSNs: 0892-6875

Abstract

Highlights: Starch adsorption on hematite was investigated by surface sensitive spectroscopy. Spectroscopic analyses indicate starch undergoes an essential oxidation process. XPS spectra indicate the formation of oxy-hydroxides under the adsorption conditions. The surface chemistry ratifies the starch strong attachment on the oxy-hydroxide. Abstract: Polysaccharides are some of the most widely employed flotation reagents in the mineral processing industry. Among several, starch is of particular importance for reverse flotation of iron ores. It is known to behave as an efficient depressant for hematite and, therefore, its interaction is of great relevance. In this paper, we investigate the surface chemistry of starch adsorbed onto hematite by means of X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Our results indicate that starch undergoes an important oxidation process under industrial gelatinization conditions, which favors the binding of starch molecules. Meanwhile, the oxide surface is subjected to full hydroxylation, leading to strong polysaccharide-metal hydroxide interaction. Previously proposed starch interaction mechanisms are discussed, and the importance of acid-base interactions is underscored.