钨尾矿粉对水泥基材料性能和微观结构的影响

以钨尾矿粉等质量取代0~40%水泥,研究其对复合水泥浆体标准稠度用水量和凝结时间的影响,采用X射线衍射(XRD)仪和扫描电镜(SEM)等表征硬化浆体的水化产物、微观形貌,并测量抗压强度。结果表明,钨尾矿粉作为混合材能增大复合水泥浆体的标准稠度用水量,延长复合水泥浆体的凝结时间,钨尾矿粉掺量在40%范围内,复合水泥浆体凝结时间均可满足普通硅酸盐水泥标准要求。硬化水泥浆体抗压强度随钨尾矿粉掺量的增加而降低,降低幅度随钨尾矿粉掺量的增加而增大,随龄期的发展有所减缓。钨尾矿粉掺量高于20%时,水化活性贡献率急剧降低。XRD测试结果表明,随着龄期的增长,钨尾矿粉-水泥硬化浆体中氢氧化钙增多,石英减少,钨尾矿粉活性逐渐被激发,水化程度提高。

Effect of Tungsten Tailing Powders on the Properties and Microstructure of Cement Based Materials

By replacing 0-40%cement with equal masses of tungsten tailing powders,the influences on water consumption of standard consistency and setting time of composite cement pastes were studied.The hydration products,microstructure and compressive strength of hardened pastes were tested by XRD and SEM,etc.The results show that the tungsten tailing powders as mixtures can increase the water consumption of the standard consistency and prolong the setting time of the composite cement pastes.When the content of the tungsten tailing powders is within 40%,the setting time of the composite cement pastes can meet the requirements of ordinary Portland cement.With the increase of the content of tungsten tailing powders,the compressive strength of hardened cement pastes decreases.And the decreasing trend of compressive strength of hardened cement pastes increases with the increase of the content of tungsten tailing powders,while slows down with the development of age.When the content of tungsten tailing powders is more than 20%,the contribution rate of hydration activity decreases sharply.The XRD test showed that with the increase of age,the Ca(OH)2 increases and the quartz decreases,the activity of tungsten tailings is gradually stimulated and the degree of hydration is improved.