Leaching behavior of metals from iron tailings under varying pH and low-molecular-weight organic acids

Huanhuan Geng; Fei Wang; Changchun Yan; Zhijun Tian; Huilun Chen; Beihai Zhou; Rongfang Yuan; Jun Yao

doi:10.1016/j.jhazmat.2019.121136

Leaching behavior of metals from iron tailings under varying pH and low-molecular-weight organic acids

J Hazard Mater. 2020 Feb 5:383:121136. doi: 10.1016/j.jhazmat.2019.121136. Epub 2019 Sep 5.

Authors

Huanhuan Geng¹, Fei Wang², Changchun Yan¹, Zhijun Tian³, Huilun Chen¹, Beihai Zhou¹, Rongfang Yuan¹, Jun Yao⁴

Affiliations

¹ School of Energy & Environmental Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, 100083, Beijing, China.
² School of Energy & Environmental Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, 100083, Beijing, China. Electronic address: wangfei@ustb.edu.cn.
³ Beijing Geo-engineering Design and Research Institute, 6 East Yuanlin Road, Miyun District, 101500, Beijing, China.
⁴ School of Water Resource and Environmental Engineering, Sino-Hungarian Joint Laboratory of Environmental Science and Health, China University of Geosciences (Beijing), 29 Xueyuan Road, Haidian District, 100083, Beijing, China.

PMID: 31525690
DOI: 10.1016/j.jhazmat.2019.121136

Abstract

The migration of metals (e.g., Fe, Cd, Co, Cr, Cu, Mn, Ni, and Zn) in both of iron tailings under different pH leachates was studied by laboratory static leaching experiments. The results indicated that Fe showed the highest leaching concentration at an initial pH of 2, reaching 16.19 and 51.72 mg L^-1 in the Qian'anling (Q0) and Majuanzi (M0) iron tailings, respectively. Metal ions manifested a strong pH dependence. In addition, the leaching behavior of Cd, Cr, Fe, and Cu for the two tailings was also evaluated under leaching by three low-molecular-weight organic acids (LMWOAs). The results indicated the leaching of Cd and Fe followed the order of citric acid > malic acid > oxalic acid and that the leaching order for Cr and Cu was citric acid > oxalic acid > malic acid. The concentration of Fe was low in 5 mM oxalic acid leaching for 20 days because of the hydrolysis precipitation of iron ions and the complexation with organic ligand. The crystal lattice on the tailings was significantly damaged after leaching. The CO₃^2- peak appeared in M0 with different treatments, and the proportion of COO- fitting peak areas increased markedly after leaching with LMWOAs.

Keywords: Iron tailing; Leaching; Low-molecular-weight organic acids; Metals; pH.

Publication types

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