Enhancing flotation recovery of residual carbon from gasification waste by mixing hydrophobic powder with diesel as collector--颗粒学报PARTICUOLOGY

Han, R., Zhang, N., Zhou, A., Li, Z., Qu, J., & Wang, H. (2024). Enhancing flotation recovery of residual carbon from gasification waste by mixing hydrophobic powder with diesel as collector. Particuology, 89, 211-217. https://doi.org/10.1016/j.partic.2023.11.011

Enhancing flotation recovery of residual carbon from gasification waste by mixing hydrophobic powder with diesel as collector

Rui Han, Ningning Zhang^*, Anning Zhou, Zhen Li, Jinzhou Qu, Hong Wang

College of Chemistry and Chemical Engineering, Xi’an University of Science and Technology, Xi’an, Shaanxi 710054, China

10.1016/j.partic.2023.11.011

Volume 89, June 2024, Pages 211-217

Received 25 September 2023, Revised 29 October 2023, Accepted 3 November 2023, Available online 20 November 2023, Version of Record 9 December 2023.

E-mail: ningningzhang@xust.edu.cn

Highlights

• The proposed novel collector promotes carbon flotation recovery from gasification waste.

• This novel collector creatively mixes diesel with hydrophobic powders.

• Hydrophobic powders reduce diesel adsorption into pore channels by blocking them.

• Hydrophobic powders adsorbed on carbon surface provide sites for diesel adsorption.

Abstract

Coal gasification fine slag (CGFS) is a solid waste containing residual carbon and ash generated during the coal gasification process, and the separation of the two components is the essential way to realize its environmental pollution reduction and resource value increase. Froth flotation is the preferred method for separating CGFS, but there is a barrier of low carbon recovery in this process due to the extensive adsorption of collector by the well-developed pores on residual carbon. In this study, a sufficiently simple yet innovative collector, a mixture of hydrophobic powder and diesel, was proposed in an attempt to break the bottleneck. Flotation experiments with common diesel and this novel collector were performed respectively, and FTIR, XPS, and SEM-EDX were employed to analyze the collector action mechanism. Flotation results revealed that the novel collector could significantly improve the residual carbon recovery; test results demonstrated that the novel collector could increase the hydrophobic functional group content on the fine slag surface, and the hydrophobic powders in this novel collector mainly appeared at the pore openings of the flotation concentrate. The essence of the mechanism is that the hydrophobic powders play a dual role of blocking pores and providing adsorption sites, thus facilitating the spreading of diesel on the carbon surface and promoting its floatability. The study can provide creative ideas for the efficient disposal of coal gasification waste.

Graphical abstract

Keywords

Coal gasification fine slag; Carbon recovery; Collector; Fotation; Hydrophobic powder

文章导读