煤粉分散稳定性的影响因素分析

Analysis on influencing factors of dispersion stability of pulverized coal

针对煤层气排采过程中煤粉产出易造成卡泵、埋泵等问题,以韩城区块太原组11号煤为研究对象,采用阴离子分散剂十二烷基硫酸钠SDS,以煤粉粒径、分散剂用量、煤粉浓度等作为影响因素,探究了分散剂对煤粉分散稳定性的影响规律,分析了分散剂与煤粉之间的相互作用机理。结果表明:不同粒径煤粉悬浮液煤粉分散效果不同,随着煤粉粒径增大,SDS悬浮液煤粉浓度出现不同程度下降;适宜的SDS分散剂用量,低的煤粉浓度,有利于煤粉在悬浮液中稳定分散,SDS分散剂质量浓度1.5~2.5 g/L,煤粉质量浓度小于30 g/L时较为适合煤粉稳定分散;分散剂的加入改变了悬浮液黏度,黏度的升高增加了携粉能力,同时不会影响洗井工艺中洗井液的返排。

Aimed at the problem of stuck and buried pump of pulverized coal during CBM extraction, the 11# coal of Taiyuan Formation of Hancheng block was studied. Using the anionic dispersant SDS, the effects of SDS on the dispersion stability of pulverized coal were investigated by the factors such as particle size of pulverized coal, the amount of dispersant and the concentration. The mechanism between dispersant and pulverized coal was analyzed. The results showed that pulverized coal suspension with different particle sizes has different dispersion effect, with the increasing of particle size, the concentration of SDS pulverized coal suspension decclined in different degrees; Suitable dosage of SDS dispersant and lower concentration of pulverized coal were beneficial to dispersion stability, the mass concentration of dispersant 1.5~2.5 g/L and the mass concentration of pulverized coal less than 30 g/L were more suitable for the stable dispersion of pulverized coal; Dispersant changed its viscosity, increased the carrying capacity, meanwhlile viscosity would not affect the flow-back effect of washing liquid in the washing process.