Effect of pectin-modified dust suppressant with different methoxy levels on wetting and agglomeration of coal: Experimental and theoretical discussion

Abstract

Low methoxy level pectin (LM-PC) and high methoxy level pectin (HM-PC) were utilized as materials to produce environmentally friendly dust suppressants, and the impact of pectin modification with different methoxy levels on wetting and agglomeration of coal was investigated. The results of contact angle and settling experiments reveal that the low methoxy level pectin-modified dust suppressant (LAT) can effectively wet coal, and the optimum modification conditions are determined. FTIR spectra of coal samples treated with LAT and high methoxy level pectin-modified dust suppressant (HAT) demonstrate that the absorption peak area ratios of hydrophilic functional groups increase by 4.00 % and 2.61 % compared to the original coal. XPS spectra indicate that the increases in carboxyl and hydroxyl functional groups are the reason for the improvement of wettability in bituminous coal. Compared to the coal samples treated with HAT, the increase of hydrophilic functional groups is higher in LAT treated coal samples. Through the dust suppression performance characterization experiments, it is concluded that LAT is more effective than HAT in reducing coal dust. The mechanism of dust suppressants on the wetting properties of coal was revealed at the molecular level. Experimental and mechanistic analyses show that LAT can effectively wet and agglomerate coal dust while remaining environmentally friendly and economical.