A review on approaches for hazardous organics removal from Bayer liquors

Ye Zhang; Rui Xu; Honghu Tang; Li Wang; Wei Sun

doi:10.1016/j.jhazmat.2020.122772

A review on approaches for hazardous organics removal from Bayer liquors

J Hazard Mater. 2020 Oct 5:397:122772. doi: 10.1016/j.jhazmat.2020.122772. Epub 2020 May 6.

Authors

Ye Zhang¹, Rui Xu¹, Honghu Tang¹, Li Wang², Wei Sun³

Affiliations

¹ School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan, 410083, China; Key Laboratory of Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral Resources, Central South University, Changsha, Hunan, 410083, China.
² School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan, 410083, China; Key Laboratory of Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral Resources, Central South University, Changsha, Hunan, 410083, China. Electronic address: li_wang@csu.edu.cn.
³ School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan, 410083, China; Key Laboratory of Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral Resources, Central South University, Changsha, Hunan, 410083, China. Electronic address: sunmenghu@csu.edu.cn.

PMID: 32388095
DOI: 10.1016/j.jhazmat.2020.122772

Abstract

Alumina is a valuable raw material for the production of adsorbents, abrasives, polishing agents, refractory materials, and aluminum. It is generally produced from bauxites through the Bayer process. Several organic compounds such as humic matters and oxalates are introduced into the Bayer liquor during the digestion process, resulting in significant hazards to precipitation of aluminum hydroxide. Therefore, it is crucial to remove these organic compounds from Bayer liquor to enhance the production of alumina. It is difficult to remove these organic compounds. Various approaches for organics removal from Bayer liquors have been developed in the past few decades, including thermal treatment, chemical precipitation, membrane technology, photocatalytic degradation, biodegradation, and wet oxidation. This paper reviews the technologies for organics removal from Bayer liquor and the relative mechanisms proposed in the literature to identify its essential parameters. Chemicals dosage, temperature, pH value, reaction time, and solution concentration are essential factors in the process. Removal efficiency, green principle, and economic viability of various methods are discussed, and potential technologies are suggested. Wet oxidation appears to be a promising method for removing organic matters in Bayer liquors. Moreover, the combination of wet oxidation and electrooxidation shows excellent potential in organics removal. Various approaches for removing organic compounds and perspectives for further investigation are proposed.

Keywords: Alumina; Bayer liquor; Hazards; Organic compounds removal; Oxidation.

Publication types

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