不同分子质量木质素磺酸钠对煤粉的分散作用研究

Sodium lignosulphonate was fractionated by means of ultrafiltration, and 4 fractions of different molecular weights were collected. It is showed by FTIR that the 5 000～10 000 fraction has the maximum hydrophilic group such as hydroxyl, phenolic hydroxyl and sulfonic group. With the increase of molecular weight, the content of hydrophilic group decreases. The results show that the adsorption curve of 10 000～50 000 fraction on coal particles approximates L type which means more adsorptive capacity, and this fraction makes the zeta potential reach –52 mV. The slurrying experiment shows that the 10 000～50 000 fraction has the best dispersing performance to Panjiang coal among all fractions. Furthermore, it is concluded that the adsorptive capacity of the dispersant on coal particles and the zeta potential are the main factors affecting the dispersing performance.