An Insight into Flotation Chemistry of Pyrite with Isomeric Xanthates: A Combined Experimental and Computational Study

Abstract

The flotation chemistry between pyrite and isomeric xanthates (butyl xanthate and isobutyl xanthate) was investigated by means of adsorption experiments, surface tension tests, and molecular dynamic simulations in this work. The flotation chemical results were confirmed and further interpreted by quantum chemical calculations. The experiment results demonstrated that the isobutyl xanthate exhibited superior adsorption capacity and surface activity than those of butyl xanthate in flotation chemistry. In addition, molecular dynamic simulations were simultaneously performed in constant number, constant volume and temperature (NVT), and constant number, constant volume, and pressure (NPT) ensemble, indicating that the NPT ensemble was more suitable to the flotation system and the isobutyl xanthate was easier to be adsorbed on pyrite surface compared with butyl xanthate during an appropriate range of concentrations. Furthermore, the quantum chemical calculations elucidated that the isobutyl xanthate presented higher reactivity than that of the corresponding butyl xanthate based on the frontier molecular orbital theory of chemical reactivity, which was consistent with experimental and simulation results obtained. This work can provide theoretical guidance for an in-depth study of the flotation chemistry of pyrite with isomeric xanthates.

Advances in depressants used for pyrite flotation separation from coal/minerals

“…The equilibrium adsorption configurations of butyl xanthate and isobutyl xanthate at different concentrations on pyrite surface corresponding to constant number, volume, and temperature (NVT), and constant number, volume, and pressure (NPT) ensembles are shown in Figs. 10 and 11 (Han et al 2018). The hydrophilic head groups of xanthate were found to be adsorbed on pyrite surface, while the alkyl chain extended into the solution.…”

Combining ozone and ultrasound technology to remove S2− in Bayer liquor

“…It reacts with alkali liquor to form various forms of sulfur, mainly namely S 2− which accounts for 90 % − 94 %, and the rest are thiosulfate ion (S 2 O 3 2− ), sulfite ion (SO 3 2− ), sulfate ion (SO 4 2− ), etc [6] . If the above sulfur compounds into the Bayer liquor with the digestion process, it will have a certain negative impact, increase the alkali consumption, decrease the decomposition rate of species, and accelerate equipment corrosion [7] , [8] . When sulfur is transferred to Bayer liquor, sodium hydroxythioferrate (Na 2 [FeS 2 (OH) 2 ]•2H 2 O), FeS 2 , ferrous sulfide (FeS) and NaFeS 2 can be formed.…”

Study on recovery of iron and sulfur from high-sulfur magnetite ore

“…Previous research showed that pyrite has some natural floatability and a small amount may be floated without collector (Han et al, 2018;Corin et al, 2018). In the presence of xanthate, 70 to 80% recovery of pyrite can be achieved by flotation in acidic to neutral pH conditions due to the formation of dixanthogen, while at other pH values, the recovery is much lower (He et al, 2011;Kelebek et al, 2007;Owusu et al, 2013).…”