Investigation into the semi-dynamic leaching characteristics of arsenic and antimony from solidified/stabilized tailings using metallurgical slag-based binders

Wei Gao; Wen Ni; Yuying Zhang; Yunyun Li; Tengyu Shi; Zifu Li

doi:10.1016/j.jhazmat.2019.120992

Investigation into the semi-dynamic leaching characteristics of arsenic and antimony from solidified/stabilized tailings using metallurgical slag-based binders

J Hazard Mater. 2020 Jan 5:381:120992. doi: 10.1016/j.jhazmat.2019.120992. Epub 2019 Aug 11.

Authors

Wei Gao¹, Wen Ni², Yuying Zhang³, Yunyun Li³, Tengyu Shi³, Zifu Li⁴

Affiliations

¹ School of Energy and Environment Engineering, University of Science and Technology Beijing, Beijing, 100083, China; Key Laboratory of High-efficient Mining and Safety of Metal Mines, Ministry of Education, Beijing, 100083, China; Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, Beijing, 100083, China.
² School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing, 100083, China; Key Laboratory of High-efficient Mining and Safety of Metal Mines, Ministry of Education, Beijing, 100083, China; Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, Beijing, 100083, China. Electronic address: niwen@ces.ustb.edu.cn.
³ School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing, 100083, China; Key Laboratory of High-efficient Mining and Safety of Metal Mines, Ministry of Education, Beijing, 100083, China; Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, Beijing, 100083, China.
⁴ School of Energy and Environment Engineering, University of Science and Technology Beijing, Beijing, 100083, China; Key Laboratory of High-efficient Mining and Safety of Metal Mines, Ministry of Education, Beijing, 100083, China; Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, Beijing, 100083, China. Electronic address: zifulee@aliyun.com.

PMID: 31437801
DOI: 10.1016/j.jhazmat.2019.120992

Abstract

The leaching characteristics of metallurgical slag-based binders (MSB) solidified/stabilized tailings containing arsenic (As) and antimony (Sb), were investigated via a series of semi-dynamic leaching tests using three kinds of leachant, for the simulation of actual leaching conditions. The effectiveness of solidification/stabilization (S/S) treatment was evaluated by measuring the observed diffusion coefficients (D_obs). It was found that MSB efficiently prevented As and Sb leaching, providing D_obs values in the range of 10^-15 to 10^-13 cm²/s and 10^-11 to 10^-9 cm²/s, respectively, with the exception that the leaching mechanism of As was dissolution rather than diffusion under acetic acid leaching conditions. Physical encapsulation was found to be the dominant mechanism for Sb immobilization, while the dominant mechanism of As immobilization was precipitation in the monolithic MSB S/S treated tailings (MST). Results showed that the concentrations of leached As, Sb, Ca and Si, were affected by leachant pH and total acidity as well as the MSB constituent ratio. The effect of these parameters may be attributed to the stability of hydration products and their influence on the buffering capacity and structure of matrices, and the leachant pH and total acidity having the greatest influence on leaching characteristics.

Keywords: Antimony; Arsenic; Metallurgical slag; Semi-dynamic leaching; Solidification/Stabilization.

Publication types

Research Support, Non-U.S. Gov't