Diatomite

Diatomite has been used as a filter aid for nearly a century. The ore is a soft, friable siliceous mineral. It is composed of the skeletons of microscopic plants deposited on the bottoms of oceans and lakes after and during the Miocene Age, from 100’000 to 15’000’000 years ago. Under the microscope the particles of diatomite show up in a variety of forms: symmetrical figures resembling disks, rods, cylinders and snowflakes. It is this shape factor combined with the rigidity of the particles that makes diatomite such an excellent raw material for the production of superior filter aids.

Diatomaceous earth is an amorphous form of silica containing a small amount of microcrystalline material. Filter aids are processed at above 800 °C (1500 °F). Both calcined and flux-calcined diatomite filter aids are free of organic matter and are non-adsorptive.

Dicalite^® diatomite filter aids offer outstanding performance from the finest to the coarsest grades. These materials meet all requirements for good filter aids. This enables them to meet the exacting clarity and flow-rate demands of industrial filtration. Even more important, the user can depend on consistency and uniformity load after load.

Typical Chemical Analysis Diatomite

Typical Properties Dicalite^® Diatomite Filter Aids

Notes

Permeability Flowrate (PFRv)

The constant volume filtration flowrate is measured by the permeability method (S.T.M. Nr. I-9).
This relative value gives an idea of the filtration speed.
It is the fundamental characteristic which differentiates one filteraid grade from another when the particles are formed into a filter bed or cake. Permeability is related to particle size distribution.

Permeability Cake Density (PCD)

The wet cake density is also measured by the permeability method (S.T.M. Nr. I-9).
This value gives the wet cake density in lbs/ft³ (x16 » kg/m³).
Perlite filteraids form lower density cakes than diatomite filteraids of comparable permeabilities. Densities of Dicalite^® perlite filteraids are controlled at a level found to be optimum for most effective performance.

Diatomite Functional Fillers

Dicalite^® Diatomite functional fillers are produced from diatomaceous earth, a versatile and valuable raw material. Diatomite consists of delicately constructed silica skeletons grown by uncounted microscopic organisms each with its own design. Deposits of these skeletons are collections of solid and perforated rods, disks, hemispheres, crescents and polygons. Because of their unusual physical structure the particles interlace and overlay in a random, three dimensional matrix which stiffens, reinforces and improves the durability of filled systems. This myriad of shapes also offers major advantages in terms of low density and high absorption.

Dicalite^® is one of only a few companies in the world that manufacture a complete line of Diatomite functional fillers. These fillers are grouped into three categories based upon the nature of the processing. Products in these groups are classified according to colour, surface area, hardness and the particle characteristics.

The effective density of Dicalite^® diatomite fillers is among the lowest of any mineral fillers at 1.98 to 2.33 gm/cc. Diatomite occupies up to 30 % more volume per pound than most competing minerals. This advantage is critical in those applications requiring light weighting.

The specifications of Dicalite^® Diatomite Functional Fillers are tabulated below.

Typical Properties Dicalite^® Diatomite Functional Fillers