Collecting behaviors of high internal phase (HIP) emulsion in flotation of ultrafine high-ash content coal slime

ABSTRACT

In order to tackle the problems of high oily collector consumption and low separation efficiency associated with ultrafine coal slimes, a new collector named high internal phase (HIP) emulsion was prepared. The flotation results showed that the HIP emulsion could significantly reduce the oil consumption by 90% compared with kerosene. The superior performance of HIP emulsion compared to kerosene was attributed to its higher flocculation ability, which was supported by the kinetic flocculation experiment and the Extended Derjaguin-Landau-Verwey-Overbeek (EDLVO) theory calculation. The preconditioning experiment showed that the high-shear pulping could greatly promote the overall flotation rate of HIP emulsion, which was due to the enhanced dispersion of the pasty HIP emulsion in the slurry as confirmed by the rheological measurement. The degradation of flocculation ability of HIP emulsion during high-shear stirring may be attributed to the microstructure damage as supported by the conductivity experiments. The HIP emulsions were proved as a potential economic and efficient collector for the beneficiation of ultrafine and high-ash content coal slimes.

KEYWORDS:

• HIP (W/O) emulsion
• ultrafine high-ash coal slime
• floc-flotation
• flocculation kinetics
• flotation kinetics
• EDLVO theory

Highlights

• HIP emulsion is highly effective for benefiting ultrafine high-ash coal slimes.

• HIP emulsion could save 90% collector dosage when achieving a similar recovery.

• High-shear prepulping could significantly promote the flotation rate by 3–4 times.

• HIP emulsion worked through a floc-flotation mechanism in the flotation process.

Acknowledgments

The authors gratefully acknowledge the financial supports by Guangdong Innovative and Entrepreneurial Research Team Program (No. 2016ZT06N532) with Shenzhen Government Related Supporting Fund (No. KYTDPT20181011104002), Development and Reform Commission of Shenzhen Municipality (No. XMHT20190203001), Shenzhen R&D Fund (No. KQTD20180411143418361), and Shenzhen Clean Energy Research Institute.

Author Contributions

Xuemin Zhao: Investigation, Writing-Original Draft. Yunmin Tang: Conceptualization, Methodology, Validation. Binglong Zhao: Calculation, Software. Changqing Chu: Writing-Review & Editing, Supervision. Changning Wu: Writing-Review & Editing. Junguo Li: Data curation. Ke Liu: Supervision, Funding acquisition, Project administration. Yulong Ding: Writing-Review & Editing.

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work was supported by the Development and Reform Commission of Shenzhen Municipality [XMHT20190203001]; Shenzhen Government Related Supporting Fund [KYTDPT20181011104002]; Shenzhen R&D Fund [KQTD20180411143418361]; Guangdong Innovative and Entrepreneurial Research Team Program [2016ZT06N532].