硅酸盐陶瓷注浆胶凝成型的机理研究

A process for making high solid loading siliscate slurry (76-78wt%) has been studied. Rheological properties of the slurries with or without adding calcium aluminate-sulphate as cementation agint and conductivities of water containing calcium aluminate-sulphate were investigated. Variations of z potentials of the slurry and the contents, which the slurry consisted of, were determined. Based upon the above studies combined with SEM investigation of formed green bodies the mechanism of consolidation of silicate slurry by addition of calcium aluminate-sulphate, as well as addition of calcium aluminate and calcium silicate was proposed. It was said that the consolidation of high solid loading silicate slurry was caused by increase of ionic strength resulting from dissolution of calcium ions into the slurry by hydrolysis of calcium salts. According to this mecanism a technique of wax-coating on the surface of calcium aluminate-sulphate was developed for delaying consolidation time. The wax layer could prevent from dissolution of calcium ions into slurry as long as the temperature of the slurry was below the melting point of the coating material. Once the temperature of the slurry above the melting point, the coating material melted out of the surface of calcium salt resulted in dissolution of calcium ions into the slurry and promoting the consolidation of the slurry

在高浓度的硅酸盐陶瓷泥浆中加入无机胶凝物质，把泥浆注入致密不吸水的模具内使其原位凝固成型。此工艺保留了传统注浆成型工艺的优点又避免使用多孔材料制造模具引起的缺点，目前对该成型工艺的内在机理尚不清楚，因此需要开展深入研究。通过对胶凝物质在泥浆中的水化动力学过程和泥浆流变学方面的研究阐明其机理，指导设计控制凝固速度的技术措施。..