Microwave hydrothermal sulfidation process for zinc-containing plating sludge

ABSTRACT

The present study describes the conversion of zinc into a sulfide-containing plating sludge via a microwave hydrothermal sulfidation (MHS) process for use in heavy metal remediation by flotation. The research herein focused on circumventing the operational issues of traditional hydrothermal sulfidation (THS) at high temperature and high pressure. The following optimized process conditions of temperature 153°C, reaction time 63 min, liquid-to-solid ratio 16:1 and S²⁻ concentration 49% were obtained using a single-factor test and the Box–Behnken design test, to yield a maximum sulfidation ratio of 92.90%. Moreover, the economic analysis shows the superiority of the MHS process.

Graphical Abstract

KEYWORDS:

• Microwave hydrothermal sulfidation
• plating sludge
• zinc sulfide
• economic evaluation

Declaration of interest statement

Neither the entire manuscript nor any part of its content has been published or has been accepted elsewhere. We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work.

Supplementary material

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Additional information

Funding

This work was supported by the Basic public research Plan Projects of Zhejiang Province (LGC19E080001), the Xin Miao Talent Program of Zhejiang Province (2019R40858), and National Undergraduate Training Program on Innovation and Entrepreneurship (201910353045 and 202010353049).