Molecular modeling study on the relative stabilities of the flotation products for arsenic-containing minerals: dixanthogens and arsenic(III) xanthates

Rejection of arsenic minerals in sulfide flotation — A literature review

“…For realgar (AsS), orpiment (As 2 S 3 ), and arsenopyrite, it is generally agreed that, using ethyl xanthate as a collector, diethyl dixanthogen and arsenic(III) ethyl xanthate are formed as major products on these mineral surfaces, since arsenic in realgar and arsenopyrite is probably oxidized to the +3 state (Persson, 1994;Valli et al, 1994;Kydros and Matis, 1995;López Valdivieso et al, 2003;López Valdivieso et al, 2006). Yekeler and Yekeler (2005) computed that the interaction energy for the formation of (C 2 H 5 SCS 2 ) 2 to be higher than that of (C 2 H 5 OCS 2 ) 2 and hence (C 2 H 5 SCS 2 ) 2 is favored in these formations.…”

Application of Quantum Chemistry in the Study of Flotation Reagents

“…Quantum chemical studies of flotation reagents towards other As-bearing minerals, such as realgar (AsS), orpiment (As 2 S 3 ), domeykite, liroconite, and enargite, are very limited. For instance, Yekeler et al [259] investigated the interactions between As(III) ions in realgar, orpiment, and arsenopyrite with two of the most popular collector ions, i.e., ethyl dithiocarbonate (C 2 H 5 OCS 2 − ) and ethyl trithiocarbonate (C 2 H 5 SCS 2 − ), using DFT at the B3LYP/6-31G** level. By comparing the stabilities of the major flotation products, namely As(III) xanthates and dixanthogens, the following conclusions were drawn: first, the O atom showed a greater electron releasing property than the S atom in xanthates; second, when the O atom was replaced by the S atom in C 2 H 5 OCS 2 − , the energies for the formations of As(III) xanthates and dixanthogens increased.…”

Equilibrium and dynamic studies of the removal of As(III) and As(V) from contaminated aqueous systems using a functionalized biopolymer

“…Xanthation has previously been used on cellulose and sawdust,17 chitin18 and chitosan12, 14 to increase the adsorption capacity. It is also well known that dixanthogen has been used as a collector for As(III) ions 19. Thus, the reactivity of both chitosan and xanthate towards arsenic would be advantageous for arsenic decontamination.…”