Formation of zinc sulfide species during roasting of ZnO with pyrite and its contribution on flotation

Yong-Xing Zheng; Jin-Fang Lv; Hua Wang; Shu-Ming Wen; Jie Pang

doi:10.1038/s41598-018-26229-3

Formation of zinc sulfide species during roasting of ZnO with pyrite and its contribution on flotation

Sci Rep. 2018 May 18;8(1):7839. doi: 10.1038/s41598-018-26229-3.

Authors

Yong-Xing Zheng^{1

2}, Jin-Fang Lv³, Hua Wang^{4

5}, Shu-Ming Wen⁴, Jie Pang⁶

Affiliations

¹ State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, 650093, China. yongxingzheng2017@126.com.
² Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, 650093, China. yongxingzheng2017@126.com.
³ Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming, 650093, China. jflv2017@126.com.
⁴ State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, 650093, China.
⁵ Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, 650093, China.
⁶ Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming, 650093, China.

Abstract

In this paper, formation of zinc sulfide species during roasting of ZnO with FeS₂ was investigated and its contribution on flotation was illustrated. The evolution process, phase and crystal growth were investigated by thermogravimetry (TG), X-Ray diffraction (XRD) along with thermodynamic calculation and scanning electron microscopy-Energy-dispersive X-ray spectroscopy (SEM-EDS), respectively, to interpret the formation mechanism of ZnS species. It was found that ZnS was initially generated at about 450 °C and then the reaction prevailed at about 600 °C. The generated Fe_xS would dissolve into ZnS and then form (Zn, Fe)S compound in form of Fe₂Zn₃S₅ when temperature increased to about 750 °C. This obviously accelerated ZnS phase formation and growth. In addition, it was known that increasing of ZnO dosage had few effects on the decomposition behavior of FeS₂. Then, flotation tests of different zinc oxide materials before and after treatment were performed to further confirm that the flotation performances of the treated materials could be obviously improved. Finally, a scheme diagram was proposed to regular its application to mineral processing. It was systematically illustrated that different types of ZnS species needed to be synthetized when sulfidization roasting-flotation process was carried out to treat zinc oxide materials.