木质素类水煤浆分散剂改性研究进展

Research progress on modification of lignin-based dispersant for coal water slurry

综述了磺化改性、缩聚改性以及接枝共聚改性在木质素磺酸盐类分散剂改性领域中的研究进展。木质素磺酸盐的磺化改性可以引入更多的磺酸基团以增强分散剂的亲水性,提高其在煤粉颗粒表面的分散性,但提浓降黏的效果有限。木质素磺酸盐通过缩聚改性能够有效增加分散剂分子的分子量和官能团的种类及数量,分散剂分子与水和煤粉颗粒的作用点均明显增多,但木质素磺酸盐缩聚改性的反应要求相对较高,通常需要对木质素磺酸盐进行一定预处理。木质素类分散剂的接枝共聚改性能够引入种类更多、功能性更强、长短可控的支链,改性后的木质素磺酸盐对水煤浆的分散性和稳定性提升显著,缺点是会使引发剂的用量、支链的大小对改性后分散剂的分散性和稳定性影响较大,改性条件的考察和优化难度较高。多种改性方法配合以及不同改性方式的合理选择是木质素类分散剂改性研究的重要发展方向。

The researche progress of sulfonation modification,polymeric modification and graft copolymerization modification in the field of lignosulfonate in recent years is reviewed.The sulfonation modification of lignosulfonate can introduce more sulfonic acid groups to enhance the hydrophilicity of dispersant and improve its dispersion on the surface of pulverized coal particles,but the effect of concentration and viscosity reduction is limited.The polycondensation modification of lignosulfonate can effectively increase the molecular weight of dispersant molecules and the type and number of functional groups.The interaction points of dispersant molecules with water and pulverized coal particles are significantly increased.However,the reaction requirements for the copolymerization modification of lignosulfonate are relatively high,and it is usually necessary to carry out certain pretreatment on lignosulfonate.The graft copolymerization modification of lignin-based dispersant can introduce more kinds,more functional and controllable length of branch chains.The dispersion and stability of modified lignosulfonate on coal water slurry are significantly improved.The disadvantage is that the amount of initiator and the size of branches will have a great impact on the dispersion and stability of the modified dispersant,and it is difficult to investigate and optimize the modification conditions.The combination of various modification methods and the rational selection of different modification methods are the important development direction of lignin-based dispersant modification research.