Type A 99.99

Alumina ceramic beads with content 99.99 % Al2O3 (“4N”)

The sintered SiLibeads® type A 99.99 grinding beads have a specific weight ≥ 3.8 g/cm3 and an aluminium oxide content ≥ 99.99 % in their chemical composition and are referred to in technical jargon as “4N” beads. These grinding beads are ideally suited for use in horizontal and vertical mills. The grinding beads are available as standard in the size range 0.2 mm to 1.8 mm, with beads in the fraction width 0.1 mm in the range 0.2 mm to 0.4 mm and in the fraction width 0.2 mm in the range 0.4-1.8 mm. Special sizes and special fractions are available on request.

Fields of application

This grinding bead quality is used in particular for the raw material preparation of technical and optical ceramic components made of aluminium oxide. Due to the very high aluminium oxide content in the chemical composition of the grinding bead, it is ensured that the aluminium oxide grinding material is virtually not contaminated by foreign bead abrasion and comes very close to autogenous grinding.

In the paint industry, SiLibeads® type A 99.99 ceramic beads are suitable for grinding and dispersing colour systems containing aluminium oxide with both inorganic and organic pigments. Due to the low specific weight, 3.8 g/cm3, these grinding beads are suitable for the preparation of suspensions with low to medium viscosity.

Quality attributes

For the ceramic beads SiLibeads® type A 99.99 finest ground raw materials are used. A sintering process individually adapted to this material contributes to the formation of the dense microstructure. The grinding beads have a matt-looking surface, as well as high roundness and are characterised by very good mechanical properties. The excellent bead quality and the coordinated selection of grinding bead size and particle size of the grinding product, with the inclusion and matching of all other properties of the grinding product, lead to high grinding and cost efficiency.


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