Eco-friendly extraction of arsenic and tungsten from hazardous tungsten residue waste by pressure oxidation leaching in alkaline solutions: Mechanism and kinetic model

Xinsheng Wu; Li Zeng; Shengxi Wu; Jialin Qing; Qinggang Li; Zuoying Cao; Mingyu Wang; Guiqing Zhang; Wenjuan Guan

doi:10.1016/j.jenvman.2022.116586

Eco-friendly extraction of arsenic and tungsten from hazardous tungsten residue waste by pressure oxidation leaching in alkaline solutions: Mechanism and kinetic model

J Environ Manage. 2023 Jan 1;325(Pt B):116586. doi: 10.1016/j.jenvman.2022.116586. Epub 2022 Nov 10.

Authors

Xinsheng Wu¹, Li Zeng¹, Shengxi Wu¹, Jialin Qing¹, Qinggang Li¹, Zuoying Cao¹, Mingyu Wang¹, Guiqing Zhang², Wenjuan Guan³

Affiliations

¹ School of Metallurgy and Environment, Central South University, Changsha, 410083, Hunan, China; Laboratory of Metallurgical Separation Science and Engineering of Central South University, Changsha, 410083, China; National Engineering Laboratory for Efficient Utilization of Refractory Non-ferrous Metals Resources, Central South University, Changsha, 410083, Hunan, China.
² School of Metallurgy and Environment, Central South University, Changsha, 410083, Hunan, China; Laboratory of Metallurgical Separation Science and Engineering of Central South University, Changsha, 410083, China; National Engineering Laboratory for Efficient Utilization of Refractory Non-ferrous Metals Resources, Central South University, Changsha, 410083, Hunan, China. Electronic address: gq_zhang@163.com.
³ School of Metallurgy and Environment, Central South University, Changsha, 410083, Hunan, China; Laboratory of Metallurgical Separation Science and Engineering of Central South University, Changsha, 410083, China; National Engineering Laboratory for Efficient Utilization of Refractory Non-ferrous Metals Resources, Central South University, Changsha, 410083, Hunan, China. Electronic address: guanwenjuan1985@163.com.

PMID: 36419310
DOI: 10.1016/j.jenvman.2022.116586

Abstract

Tungsten residue waste (TRW), considered an environmental burden due to high content and excessive leaching toxicity of arsenic (As), are also secondary tungsten (W) resources. A novel method for simultaneous extraction of arsenic and tungsten from TRW via alkaline pressure oxidative leaching was proposed. The results show that As in the TRW mainly exists in the form of As coprecipitated with Mn(Ⅱ) oxides and FeAsS. In addition, As coprecipitated with Mn(Ⅱ) oxides and W are encapsulated in Fe, Mn oxides. The structure of Fe, Mn oxides with dense surface can be destroyed and the chemically stable arsenopyrite can be efficiently oxidized by oxygen in alkaline solutions. The leaching efficiency of As and S reached 97% and 99% at 80 min, respectively, while that of W reached 82% at 10 min. The leaching rate of As and S is controlled by diffusion with the apparent activation energies of 16.67 kJ/mol and 15.66 kJ/mol, respectively. Compared with TRW, the leaching toxicity of As in the leach residue decreased from 10.2 mg/L to only 0.071 mg/L. The new process suggests new possibilities for removal and recovery of As and W from TRW that will contribute to circular economy and environmental protection.

Keywords: Extraction of arsenic and tungsten; Leaching kinetic and mechanism; Pressure oxidation leaching; Tungsten residue waste (TRW).

MeSH terms

Arsenic*
Hazardous Waste
Oxidation-Reduction
Oxides
Tungsten*

Substances

Tungsten
Hazardous Waste
Arsenic
Oxides