Introduction
To select a suitable dispersant for slurry casting, it is necessary to comprehensively consider particle characteristics (particle size, surface charge, composition), the liquid medium (slurry casting typically uses water), and the chemical properties of the dispersant. It is also necessary to evaluate its compatibility with other raw materials, the required stability, as well as specific requirements for application characteristics such as gelation time and flow rate. For most ceramic slurry casting processes, different anionic dispersants need to be tested to obtain a stable slurry with low viscosity and good fluidity.
Select the reference indicator guide:
| Particle characteristics: | Liquid medium: | Anion dispersant: | ||
| The dispersant must be able to adsorb onto the surface of specific ceramic particles, which requires its anchoring groups to be chemically compatible with the particle surface. | Since slurry casting is typically performed in aqueous media, dispersants suitable for aqueous environments must be selected, such as hydrophilic surfactants or anionic polyelectrolytes. To improve casting performance, the amount of water should be minimized, and therefore, the dispersant must remain effective under low water content conditions. | It is applicable to various ceramic materials such as kaolin and alumina, and works by generating electrostatic repulsion between particles. | ||
| Compatibility: | Performance requirements: | Gelation test: | ||
| Dispersants must be compatible with all other components in the slurry to avoid adverse reactions or flocculation (clumping). | Slurry casting requires the slurry to have good fluidity and drainage properties, and to not gel too quickly. Different dispersants and quantities need to be tested to find the balance point for specific application scenarios. | This test measures the density of slurry and can be used to understand its viscosity and water content. Observe the duration each type of slurry maintains its pourable state. A balance needs to be achieved between the operability of the slurry and its normal curing after pouring. |
Evaluation results: The optimal dispersant should be able to prepare the most stable and low-viscosity slurry, with ideal pouring time, and form a high-quality, high-strength, and uniform green body.
Selecting the appropriate dispersant is a critical step in optimizing ceramic slip casting performance. Successful selection must be based on a systematic analysis of particle surface characteristics, medium environment, and process requirements. By scientifically evaluating the adsorption properties, compatibility, and impact on rheological behavior of dispersants, and combining experimental verification with key process parameters such as gelation time, the optimal dispersant solution that provides low viscosity and high stability to the slip can be precisely screened. This refined selection process is decisive in improving casting quality and reducing production defects.