不同来源木质素磺酸钠对水煤浆流变特性的影响

Effect of the Sodium Lignosulphonate from Different Material on Rheological Behavior of Coal Water Slurry

针对木质素磺酸盐结构复杂,用作水煤浆分散剂性能差异较大的特点,分别研究了来源于木材、麦草、竹子和蔗渣造纸黑液的木质素磺酸钠作为水煤浆分散剂的性能,结果发现木材和竹子木质素磺酸钠的分子量较高,对水煤浆的分散降黏性能优于麦草和蔗渣木质素磺酸钠。采用流变仪测试水煤浆的流变性,用Herschel-Bulkley模型对不同浆体的流变曲线进行拟合,发现掺竹子和蔗渣木质素磺酸钠的水煤浆浆体的假塑性较强,触变环面积较大,浆体的稳定性较优;而掺木材和麦草木质素磺酸钠的水煤浆浆体多表现出轻微的胀塑性特征,触变环面积较小,稳定性较差。

The sodium lignosulphonate （SL） of the black liquor originated separately from wood, straw, bamboo and bagasse were used as dispersant for coal water slurry （CWS）, and the influences of the complex molecular structure of SL on the viscosity-reducing ability, the rheological behavior and thixotropy of CWS were studied. The Haake rheometer was used to measure the rheological properties, and the rheological data-- the shear-stress/shear rate data of each CWS prepared with different SL were fitted by using the three-parameter Herschel-Bulkley model. Moreover, the thixotropy loop area was calculated to characterize the thixotropy of CWS. The results show that the CWS prepared with bamboo or bagasse SL exhibits evidently pseudoplastic characteristic, stronger thixotropy and better stability. However, the CWS prepared with wood or straw SL shows slightly dilatant characteristic, weaker thixotropy and worse stability. Furthermore, the difference of rheological properties of CWS is associated with the molecular weight and the functional groups content of the used SL.