Preparation of an additive using tannic acid for enhancing rheological properties of coal-water slurry

ABSTRACT

Low-rank coal is an ideal future development coal for coal-water slurry (CWS) due to its abundant resource, but low-rank coal is tougher to produce slurry than high-rank coal. Herein, a new-type macromolecular additive, tannic acid grafted carboxymethyl cellulose sodium (TAC), was designed and prepared to enhance the rheological properties of CWS using Hongshaquan coal in Xinjiang (Coal-HSQ). This work shows that trace amounts of TAC can effectively improve the fluidity of CWS in comparison with calcium lignosulfonate (CLS). Through contact angle and a novel surface characterization method in this field called microscopic infrared imaging, the analyses reveal the hydrophobicity of the Coal-HSQ surface modified by TAC is improved, which is beneficial for enhancing the fluidity of CWS. The apparent viscosity of CWS can be reduced to the lowest point (674.8 mpa·s), as CWS slurry concentration is 55 wt% and TAC addition is only 0.2 wt%. Finally, the highest slurry concentration of CWS prepared with 0.2 wt% TAC can be increased to 56.3 wt%.

KEYWORDS:

• Low-rank coal
• coal-water slurry
• preparation
• additive
• Rheological properties

Disclosure statement

No potential conflict of interest was reported by the author(s).

Authors in detail

Ke Wang: Xinjiang university 3,409,634,[email protected], Conceptualization, Methodology, Formal analysis, Writing – original draft, Writing – review & editing. Murong Xi and Zhenjie Liu:Xinjiang university 1,579,760,[email protected] and 1,161,688,[email protected], Data analysis, Methodology, Writing – review & editing. Jiafeng Zhu: Xinjiang university 1,271,925,[email protected], Writing – review & editing. Yudai Huang: Xinjiang university, [email protected], Funding acquisition, Writing – review & editing, Supervision.

Additional information

Funding

This work was financially supported by the Key Project of Nature Science Foundation of Xinjiang Province [2021D01D08], the National Natural Science Foundation of China [52162036, 21965034, U1903217, and 22378342], the Xinjiang Autonomous Region Major Projects [2022A01005-4 and 2021A01001-1].

Notes on contributors

Ke Wang

Ke Wang is a candidate for degree of master at the College of Chemistry, Xinjiang University.

Murong Xi

Murong Xi is a candidate for degree of doctor at the College of Chemistry, Xinjiang University.

Jiafeng Zhu

Jiafeng Zhu is a candidate for degree of doctor at the College of Chemistry, Xinjiang University.

Zhenjie Liu

Zhenjie Liu is a candidate for degree of doctor at the College of Chemistry, Xinjiang University.

Yudai Huang

Yudai Huang currently is a professor who works at the College of Chemistry, Xinjiang University.