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 100000 to 15000000 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.
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.
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.