水玻璃模数对高岭土浆料流变性的影响

摘要/Abstract

摘要： 本文制备了不同模数的水玻璃,研究了水玻璃模数对高岭土浆料流变性的影响。通过流变分析,确定了水玻璃模数为2.5、添加量为0.33%(质量分数)时,高岭土浆料的剪切黏度最低。采用四种不同模型对流动曲线进行拟合,发现Herschel-Bulkley模型的拟合相关性最大。另外,拟合度的高低主要取决于低剪切速率区的剪切应力,而这主要受浆料触变性的影响。然后利用剪切滞后环面积表征了不同水玻璃模数浆料的触变性,验证了此观点。最后采取红外光谱测试,对不同模数水玻璃的分子结构进行了研究。研究表明,在模数为2.5的水玻璃的振动光谱589.5 cm^-1处观察到一个微弱的振动峰,表示存在变形的6元环结构。环状硅酸根通过库仑力与高岭土颗粒结合,避免高岭土颗粒之间的棱面连接,破坏了触变结构,从而降低了黏度。本研究有助于理解水玻璃模数影响高岭土解胶机理的深层次原因,为优化陶瓷浆料的配方和加工提供科学依据。

关键词: 水玻璃, 模数, 高岭土, 浆料, 流变性, 触变性

Abstract: In this study, sodium silicate with varying modulus was synthesized. The influence of sodium silicate modulus on the rheology of kaolin slurry was investigated. Based on the rheological analysis, it has been determined that the kaolin slurry exhibits the lowest shear viscosity when the sodium silicate modulus is 2.5 and the addition amount is 0.33% (mass fraction). Four different models are used to fit the flow curves, and it is found that the Herschel-Bulkley model could obtain the greatest correlation. In addition, the fitting degree is primarily influenced by the shear stress in the low shear rate region, which is mainly affected by the thixotropy of slurry. Then, the thixotropy of slurry with different sodium silicate modulus is characterized by shear hysteresis ring area, which verifies the view above. Finally, the molecular structure of sodium silicate with different modulus was analyzed using infrared spectroscopy. The results indicate the presence of a weak vibration at 589.5 cm^-1 in the vibrational spectrum of sodium silicate with a modulus of 2.5, suggesting the presence of distorted 6-membered rings. The annular silicates interact with kaolin particles through Coulombic force, leading to the formation of large aggregates. This interaction prevents the connection between the edges and faces, disrupts the thixotropic structure, and consequently reduces viscosity. This study is helpful to understand the deep reason of the influence of sodium silicate modulus on the mechanism of deflocculation, and provide scientific basis for optimizing the formulation and processing of ceramic slurry.

Key words: sodium silicate, modulus, kaolin, slurry, rheology, thixotropy

中图分类号:

TQ174

李钢, 鲍志蕾, 张军剑, 于欢. 水玻璃模数对高岭土浆料流变性的影响[J]. 硅酸盐通报, 2023, 42(12): 4475-4481.

LI Gang, BAO Zhilei, ZHANG Junjian, YU Huan. Influence of Sodium Silicate Modulus on Rheology of Kaolin Slurry[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2023, 42(12): 4475-4481.

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