Analysis of enhancing moisture-proof and waterproof performance for lignite powder briquette

ABSTRACT

There are abundant resources of low-rank coal powder in the world. Powder briquetting technology has opened up a new avenue for large-scale utilization of low-rank coal. Water repellency is of great importance for the storage and transportation of lignite briquettes. In this paper, different water repellents were investigated to improve the moisture and water resistance of briquettes. The results showed that the moisture-proof and waterproof effect of briquette with the silicone emulsion was better than other briquettes. After 132 h of moisture absorption experiment, the briquette with the silicone emulsion absorbed only 1.8 wt% of water finally and was less 4.7 wt% than the briquette without water repellent. After 24 h of water immersion experiment, the water absorption of briquette with the silicone emulsion reached 19.74%. The addition of water repellent improved the water immersion strength and re-drying water immersion strength, of which briquette with the silicone emulsion were 4.91 KN/piece and 9.37 KN/piece. The waterproof mechanism was explored by scanning electron microscopy and wettability. It was proved that the addition of silicone emulsion, polyurethane, and acrylic emulsion played a positive role in the waterproofing of lignite briquette.

KEYWORDS:

• Water-proof
• moisture-proof
• lignite briquetting
• mechanism

Additional information

Funding

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), the Postdoctoral Science Foundation of Shandong Province (201903073).