A new method of sulfur recovery from coking waste liquor

ABSTRACT

The traditional ammonia desulfurization process (TADP) is mainly used in the coking process of coal. The disadvantage of this process is that it produces ammonium sulfate, sodium sulfate, gypsum, and other low value-added by-products, as well as a large number of sulfur-containing wastewater, which seriously restricts the green development of the coal chemical industry. In this study, the TADP has been effectively improved. A late-model, ecologically friendly, economical, and feasible treatment method for sulfur-containing wastewater was designed. The novel ammonia desulfurization process (NADP) not only realized the high added value utilization of sulfur but also greatly saved water resources by recycling wastewater. The key to this process is to connect the crystallization reactor with the rich liquid outlet of the TADP, which simplifies the desulfurization process and improves the desulfurization efficiency. The sulfur content of coking desulfurization wastewater in the NADP was determined using Ultraviolet-Visible Spectrophotometer. The sulfur removal efficiency was up to 91.5%, indicating that it is feasible to recover sulfur from sulfur-containing wastewater by NADP. The by-product zinc sulfide (ZnS) powder was characterized by XRD, SEM, EDS, TEM, and FT-IR. The results showed that the cubic ZnS powder with high added value could be obtained by NADP desulfurization. This process can provide evidence for effective removal of sulfur from sulfur-containing wastewater and green production of resource utilization.

KEYWORDS:

• Desulfurization wastewater
• sulfur
• coal
• environmentally protective
• ZnS

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was supported by the Region Special Fund for Collaborative Innovation of Xinjiang (Scientific research fund for colleges and universities in the autonomous region) (Grant No. XJEDU2019I025). The opinions expressed in this article are the author’s own.