Na_(2)CO_(3)对红沙泉褐煤水煤浆流变性的影响  

Influence of Na_(2)CO_(3) on the rheology of Hongshaquan lignite water slurry

作　　者：白天祥 刘胜 谢咏波 刘霖 刘钐 涂亚楠[2,3] BAI Tianxiang;LIU Sheng;XIE Yongbo;LIU Lin;LIU Shan;TU Yanan(CHN Energy Xinjiang Chemical Co.,Ltd.,Urumqi 831404,China;China University of Mining and Technology-Beijing,Beijing 100083,China;CUMTB Inner Mongolia Research Institute,Ordos 017001,China)

机构地区：[1]国能新疆化工有限公司,新疆乌鲁木齐831404 [2]中国矿业大学(北京),北京100083 [3]中国矿业大学(北京)内蒙古研究院,内蒙古鄂尔多斯017001

出　　处：《煤炭工程》2024年第12期185-191,共7页Coal Engineering

基　　金：国能新疆化工有限公司“新疆化工提高红沙泉和黑山煤不同比例水煤浆质量的方法研究”(GJNY-21-〔2024〕-1)。

摘　　要：针对褐煤难以制备高浓度水煤浆的问题,利用Na_(2)CO_(3)与亚甲基双萘磺酸钠(NNO)制备了复配型分散剂,研究了单一分散剂NNO和复配药剂对褐煤水煤浆特性的影响,考察了不同药剂制备的褐煤水煤浆颗粒的Zeta电位、接触角、孔隙结构及孔径分布的变化情况,探索了成浆浓度及流变性的变化机理。结果表明:采用复配药剂制浆时,褐煤水煤浆的成浆质量浓度(剪切率100 s-1时黏度为1200 mPa·s)从59.89%增大到60.53%,屈服应力从24.12 Pa增大到38.85 Pa,流动性指数从0.69降低到0.56,假塑性增强。褐煤吸附分散剂NNO后Zeta电位绝对值从28.3 mV增大到36.1 mV,接触角从74.5°降低到65.3°;加入Na_(2)CO_(3)后,Zeta电位绝对值降低到34.6 mV,接触角降低到57.5°。复配药剂制备的水煤浆颗粒相较于使用单一分散剂NNO而言,比表面积从2.7442 m 2/g降低到2.4264 m 2/g,大孔占比由70.71%降低到54.15%,中孔占比由25.68%增大到41.27%。上述试验结果表明Na_(2)CO_(3)优化了水煤浆体系中的离子环境,促进了NNO在褐煤颗粒表面的吸附,使得接触角和Zeta电位降低,引起分散剂对褐煤颗粒的降黏分散效果升高、黏度降低;此外,通过缔合溶解的金属离子形成沉淀而堵孔的作用向体系内释放更多的自由水,从而降低体系表观黏度。Aiming at the difficulty in preparing high concentration lignite water slurry(LWS),a compound dispersant was prepared based on the compound of Na_(2)CO_(3) and sodium methylene dinaphthalene sulfonate(NNO).The effects of NNO and the compound dispersant on the LWS properties were investigated.The changes in zeta potential,contact angle,pore structure and pore size distribution of LWS particles with different agents were analyzed to explain the mechanism in slurry concentration and rheological properties.The results show that the mass concentration increased from 59.89%to 60.53%,and the yield stress increased from 24.12 Pa to 38.85 Pa when the slurry was made with the compound dispersant.Besides,the fluidity index decreased from 0.69 to 0.56 indicating that the pseudoplasticity was increased by Na_(2)CO_(3).The absolute value of zeta potential increased from 28.3 mV to 36.1 mV and the contact angle decreased from 74.5°to 65.3°after NNO adsorption on lignite.With the addition of Na_(2)CO_(3),the absolute value of zeta potential decreased to 34.6 mV and the contact angle decreased to 57.5°.Compared with NNO,the specific surface area of the particles decreased from 2.7442 m 2/g to 2.4264,the content of macropores decreased from 70.71%to 54.15%,while the content of mesopores increased from 25.68%to 41.27%.These results indicated that Na_(2)CO_(3) optimizes the ionic environment in the coal-water slurry system and promotes the adsorption of NNO on the surface of lignite particles,which reduces the contact angle and zeta potential,causing the viscosity reduction.In addition,Na_(2)CO_(3) formed precipitates with the metal ions dissolved in LWS system so that the pores was plugged and drove more free water releasing,thus reducing the apparent viscosity of LWS.

关 键 词：褐煤 水煤浆 流变性 分散剂 

分 类 号：TQ536[化学工程—煤化学工程]