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The effect of oxidized starches on chalcopyrite flotation

2021; Elsevier BV; Volume: 165; Linguagem: Inglês

10.1016/j.mineng.2020.106749

1872-9444

Wonder Chimonyo, Brenton Fletcher, Yongjun Peng,

Extraction and Separation Processes

In our previous study, a NaClO oxidized wheat starch (Ox 5/120) showed promising selectivity between chalcopyrite and graphite flotation compared to the native counterpart. Building from that, this paper presents a systematic investigation conducted on a series of NaClO oxidized starches in a quest to minimize chalcopyrite depression during flotation. Active chlorine of different concentrations was used in the synthesis of the starch derivatives (Ox 1/120, Ox 5/120 and Ox 10/120). Each chlorine level varies the degree of starch oxidation with respect to depolymerisation leading to new orders of molecular weight and size distributions of the polymer fractions. This is in conjunction with the proportion and type of carbonyl functional groups generated. A combination of adsorption isotherms and nanoscale characterisation using AFM revealed dissimilar adsorbability and visual morphological features, providing new insights into the depressive actions of oxidized starches during chalcopyrite flotation.