Mineral Pigments & Fillers

Mineral pigments and fillers like TiO₂, CaCO₃, talc, clay, barites or zeolites are processed in large mills with long production runs. A primary challenge is to minimize the energy spent to achieve the target grind. Determining the correct media is critical to optimize the grind and to maintain operational efficiency. Bead density and size are the main selection criteria; choosing the correct combination has a significant impact on overall process economies.

Saint-Gobain ZirPro has been supplying high-quality ceramic media to the mineral pigments and fillers industries for more than 40 years, offering the market-leading range of beads. ER120, Rimax^®, Zirmil^® Ce and Zirmil^® Y are designed to meet the exacting demands of each specific product type and process. ZirPro also offers a unique level of after-sales and technical support.
 

ZirPro beads to improve cost efficiency

For many minerals, a mid-density media (4.0 g/cc) is optimal to provide the correct combination of stress intensity and impact probability. Both ER120 and Rimax are considered standards because their uniform structure ensures a controlled wear profile. This limits the generation of rough surfaces, reducing the risk of contamination from media and mill wear, as well as minimizing energy loss in bead-to-bead interactions. A more recent development in processing minerals is the use of Zirmil Y and Zirmil Ce. Their higher density (6.0 g/cc) provides a more efficient grind. Operating costs are reduced as both media have significantly extended lifetimes.
 

Bead-size effect on grinding

Bead size has a number of effects on the final grind results.  For a given bead density, the size must be large enough either to break down primary grains or, in many cases, to de-agglomerate. Achieving a precise and consistent particle size distribution of the product requires a stable media size range in the mill.

TiO2 – particle size development with bead size selection