Reductive roasting of arsenic-contaminated red mud for Fe resources recovery driven by johnbaumite-based arsenic thermostabilization strategy

Yang，Dazhong1; Shi，Manyu3; Zhang，Juan2; Sasaki，Atsushi3; Endo，Masatoshi3

2023-06-15

10.1016/j.jhazmat.2023.131255

Journal of Hazardous Materials   Impact Factor & Quartile

0304-3894

1873-3336

Arsenic-contaminated red mud (As-RM) is a hazardous waste with limited recycling approaches. Generally, through reductive roasting and magnetic separation, RM could be transformed into Fe-rich concentrate for Fe resource recovery. However, due to the poor thermostabilization of As species, reductive roasting of As-RM would cause severe As volatilization pollution together with high As leaching risks from heated residue. Herein, a novel johnbaumite-based As thermostabilization strategy is developed for clean Fe resources recycling from As-RM. We found that in the presence of Ca(OH), the As species in As-RM could be immobilized as thermostable and insoluble johnbaumite (Ca(AsO)OH) at 900 °C, effectively enhancing the As thermostability and insolubility. Introducing 1.5% Ca(OH) into As-RM suppressed the As volatilization ratio from 60.3% to 15.7% during reductive roasting. Meanwhile, the As leaching concentration of the reduced residue was reduced to < 100 µg/L, thus satisfying the Japanese wastewater discharge standard. A concentrate with approximately 67.5% total iron grade was obtained from As-RM through this clean reductive roasting and magnetic separation. Overall, the approach introduced in this work effectively reduces the As diffusion pollution deriving from As-RM thermal reduction, which could contribute to hazardous As-RM reutilization, clean Fe resources recovery, and As pollution mitigation.

As thermostabilization Iron resource recovery Johnbaumite Red mud Reductive roasting

English

First ; Corresponding

National Natural Science Foundation of China[22106064];

ENGINEERING

2-s2.0-85151022222

Scopus

1.Department of Ocean Science and Engineering,Southern University of Science and Technology,Shenzhen,China
2.School of Environmental Science and Engineering,Southern University of Science and Technology,Shenzhen,China
3.Graduate School of Science and Engineering,Yamagata University,Yamagata,Jhonan 4–3–16 Yonezawa,992–8510,Japan

Yang，Dazhong,Shi，Manyu,Zhang，Juan,et al. Reductive roasting of arsenic-contaminated red mud for Fe resources recovery driven by johnbaumite-based arsenic thermostabilization strategy[J]. Journal of Hazardous Materials,2023,452.

Yang，Dazhong,Shi，Manyu,Zhang，Juan,Sasaki，Atsushi,&Endo，Masatoshi.(2023).Reductive roasting of arsenic-contaminated red mud for Fe resources recovery driven by johnbaumite-based arsenic thermostabilization strategy.Journal of Hazardous Materials,452.

Yang，Dazhong,et al."Reductive roasting of arsenic-contaminated red mud for Fe resources recovery driven by johnbaumite-based arsenic thermostabilization strategy".Journal of Hazardous Materials 452(2023).