Optimization of composite binder for Lignite powder briquetting

ABSTRACT

Lignite briquetting provided an effective method for the utilization of lignite powder. Based on the briquetting conditions of lignite, two kinds of binders (sodium humate and polyvinyl alcohol) were selected for the present study. The compressive and drop strengths of briquette were used as indicators to design an orthogonal experiment to examine the effect of composite binders. From the analysis of Fourier transform infrared spectroscopy, sodium humate contained active oxygen-containing groups of -OH and -COOH, it would have strong adsorption during briquetting. Polyvinyl alcohol was a long-chain structure containing -OH functional groups, which played a role in the briquetting process. Using the orthogonal design method, the optimal composite ratio of polyvinyl alcohol and sodium humate was obtained as follows: 2 wt% of sodium humate and 0.5 wt% of polyvinyl alcohol. From the scanning electron microscope, there was a fibrous structure of polyvinyl alcohol and solid bridge formed by the solidification of sodium humate on the surface of the briquette, which made the mechanical strength of briquette stronger.

KEYWORDS:

• Lignite
• briquetting
• orthogonal experiment
• binder

Acknowledgments

This work was supported by the “National Natural Science Foundation of China” (51974311 and 51704292), the Key Research and Development Plan of Shandong Province (2019GGX103002), and the Postdoctoral Science Foundation of Shandong Province (201903073).

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [51974311 and 51704292]; Key Research and Development Plan of Shandong Province [2019GGX103002]; Postdoctoral Science Foundation of Shandong Province [201903073].