A comparison of ultrasound-augmented and conventional leaching of silver from sintering dust using acidic thiourea

Jun Chang; Er-Dong Zhang; Li-Bo Zhang; Jin-Hui Peng; Jun-Wen Zhou; C Srinivasakannan; Chang-Jiang Yang

doi:10.1016/j.ultsonch.2016.05.038

A comparison of ultrasound-augmented and conventional leaching of silver from sintering dust using acidic thiourea

Ultrason Sonochem. 2017 Jan:34:222-231. doi: 10.1016/j.ultsonch.2016.05.038. Epub 2016 May 24.

Authors

Jun Chang¹, Er-Dong Zhang¹, Li-Bo Zhang¹, Jin-Hui Peng², Jun-Wen Zhou³, C Srinivasakannan⁴, Chang-Jiang Yang⁵

Affiliations

¹ State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, Yunnan 650093, China; Kunming University of Science and Technology, Faculty of Metallurgical and Energy Engineering, Kunming, Yunnan 650093, China.
² Kunming University of Science and Technology, Faculty of Metallurgical and Energy Engineering, Kunming, Yunnan 650093, China; Yunnan Minzu University, Kunming, Yunnan 650031, China.
³ State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, Yunnan 650093, China; Kunming University of Science and Technology, Faculty of Metallurgical and Energy Engineering, Kunming, Yunnan 650093, China. Electronic address: zhoujunwen520@126.com.
⁴ Chemical Engineering Program, The Petroleum Institute, P.O. Box 2533, Abu Dhabi, United Arab Emirates.
⁵ Kunming University of Science and Technology, Faculty of Metallurgical and Energy Engineering, Kunming, Yunnan 650093, China.

PMID: 27773239
DOI: 10.1016/j.ultsonch.2016.05.038

Abstract

In the process of steel manufacture, up to ten millions of tons of sintering dust (SD) are produced annually in China, which contain noble metals such as Ag. Therefore, recovery of silver (Ag) from SD could be a potential economic and environmental activity. The purpose of this article is to generate information about reaction kinetics of silver leaching with thiourea from SD, comparing the conventional and ultrasonic-augment leaching. The effects of various control parameters such as the ultrasound power, particle size, leaching temperature and thiourea concentration on leaching rate of silver were studied. The results showed 89% silver recovery for conventional process against 95% for ultrasound assisted leaching. The ultrasonic wave increased the leaching rate and shorten the reaction time. The rate controlling step was analyzed using shrinking core model and the rate controlling step is identified to be the diffusion through the product layer in both conventional and ultrasonic-augment leaching processes. The activation energies were estimated to be 28.01kJ/mol and 18.19kJ/mol, and the reaction order were 0.89 and 0.71, respectively.

Keywords: Acidic thiourea; Conventional; Dissolution kinetic; Silver; Sintering dust; Ultrasound augmented.

Publication types

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