摘要
粉煤灰存在保水性差、易干燥开裂等问题导致其应用受限。为提高粉煤灰的保水性能,通过向粉煤灰浆液中添加不同质量比的黄原胶(XG)、魔芋胶(KGM)亲水胶体制备了含亲水胶体的粉煤灰浆液,测试材料胶凝特性、稳定性及流变特性并浅析其成胶机理。结果表明:不同质量比XG/KGM亲水胶体粉煤灰浆液的成胶状态不同,当质量比大于4∶6时,粉煤灰浆液可成胶,120℃条件下热失水率最低为18.14%,稳定性良好,Zeta电位绝对值均在20 mV以上,1000℃条件下最大质量损失约为6.27%;流变试验表明,粉煤灰浆液均存在剪切稀化现象,为假塑性流体,采用Herschel-Bulkley模型进行拟合,R2均在0.99以上;储能模量G'均高于损耗模量G″,表明粉煤灰浆液以弹性性质为主;可成胶的三组即质量比为6∶4、8∶2、10∶0时,样品表面可观察到不规则的块状、片状形貌亲水胶体;成胶机理表明,粉煤灰与XG、XG与KGM之间可发生复杂相互作用,从而促进粉煤灰浆液成胶。
The poor water retention and susceptibility to drying and cracking of fly ash limit its application.To improve the water retention performance of fly ash,a fly ash slurry containing hydrophilic colloids was prepared by adding different mass ratios of xanthan gum(XG)and konjac gum(KGM)hydrophilic colloids to the fly ash slurry.The material’s cementitious properties,stability,and rheological properties were tested,and its gelation mechanism was analyzed.The results showed that the gelation state of XG/KGM hydrophilic colloidal fly ash slurry varied with different mass ratios.When the mass ratio was greater than 4∶6,the fly ash slurry can gelation,and the lowest thermal water loss rate was 18.14%at 120℃.The stability was good,and the absolute Zeta potential values were all above 20 mV.The maximum mass loss at 1000℃was about 6.27%;The rheological experiment showed that there was shear thinning phenomenon in all coal ash slurry,which was a pseudoplastic fluid.The Herschel-Bulkley model was used for fitting,and the R2 was above 0.99;The energy storage modulus G'was higher than the loss modulus G″,indicating that the fly ash slurry mainly had elastic properties;When the mass ratios of the three groups that can form gels were 6∶4,8∶2,and 10∶0,irregular block and sheet shaped hydrophilic colloids can be observed on the surface of the samples;The gelation mechanism indicated that complex interactions can occur between fly ash and XG,XG and KGM,thereby promoting the gelation of fly ash slurry.
作者
王慧
张德飞
魏高明
王光明
张德灿
张佳敏
WANG Hui;ZHANG Defei;WEI Gaoming;WANG Guangming;ZHANG Decan;ZHANG Jiamin(College of Safety Science and Engineering,Xi’an University of Science and Technology,Xi’an 710054,China;Huafeng Coal Mine of Xinwen Mining Group Co.,Ltd.,Taian 271413,China;Yili New Mining Coal Industry Co.,Ltd.,Yili 835000,China;Baodian Coal Mine of Yankuang Energy Group Co.,Ltd.,Zoucheng 273513,China)
出处
《煤炭工程》
北大核心
2024年第7期193-199,共7页
Coal Engineering
基金
国家自然科学基金项目(52174206)
陕西省科技创新团队项目(2023-CX-TD-42)
陕西省教育厅青年创新团队项目(22JP047)。
关键词
粉煤灰
黄原胶
魔芋胶
胶凝特性
流变特性
稳定性
fly ash
xanthan gum
konjac gum
gelling property
rheological properties
stability
