Rheology of ceramics slurries with mixtures of deflocculanting agents.

In whiteware processing, as in most other technical processes involving concentrated suspensions, additives are used to decrease viscosity and control stability. Silicate, phosphate and polyacrylate sodium salts are the most used additives in the production of tiles, tablewares, sanitarywares etc. They are commercially available products with good deflocculant abilities and performance/costs ratio. The chemical action of each single component was studied1,2,3 but the authors are not aware of any studies on mixtures. The systems are complex because they are multi-phases and constituted by natural raw material. In the industrial field, liquid mixture of additives are generally used. They take an inferior amount of time before being active with respect to when they are used as solid salts and permit a better management in the plant.