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Diatomaceous Earth

Mineral Adsorbents, Filter Agents and Drying Agents

Home / Molecular Sieves / Activated Alumina / Activated Carbon / Diatomaceous Earth
Ascarite II® Adsorbents / Montmorillonites and other Mineral Adsorbents / Drying Agents
Toxicity and Handling / References


Known by a variety of tradenames, diatomaceous-earth products find common use as filter agents and all-purpose adsorbents, as well as in specialized applications, such as catalyst carriers. These products, also known as diatomaceous silicas, are powders generally having a silicon dioxide assay of about 90%.

The CAFA (Celite® Analytical Filter Aid) product is double-acid-washed to remove trace metal oxides and contains about 97.5% SiO2. It is useful as an analytical filter agent and for high-purity applications.

Celite 521 is acid-washed and contains about 94% SiO2. It is suitable for use where exceptional purity is desired.

The Celatom® products are flux-calcined, with a pH (10% slurry) of 8.0-9.5, and specific gravity of 2.33.

Table 7
Catalog No. 167436 221791 243310 243329 243337 243345
Grade CAFA Celite Celatom
Flow rate 100 200 700 2500 3000 5500
Median size (µ) 2.5 3.5
Clarity 1000 500 969 940 936 927
Acid-soluble iron (ppm) 60 15
Wet density
(lb/cu ft)
17 19-90 19 18 18 17
Avg. particle size (µ) 7.5 14 8 15 19 23
Moisture (%) 1 0.5
Color white-grey/ pink light-pink
to tan
white white white white
Celite is a registered trademark of JohnsManville Corp.
Celatom is a registered trademark of EaglePicher Industries, Inc.