THE USAGE
OF DIATOMITE

Diatomaceous Earth is a fossilized siliceous sedimentary rock composed mainly of silica from diatoms, which are a type of phytoplankton, and it is piled on the sea bottom or lake bed for 8 to 10 million years. It is chalk-like, soft, friable and has beds like extremely fine natural earth powder, and an aggregate of geological siliceous deposits composed chiefly of tiny free-floating algae 50 to 100 micrometers in size. It is a very finely porous material and when extremely low density sediments have turned into sedimentary rock from the pressure resulting from diagenesis, we call it Diatomaceous Earth.

This light, brittle material derived from fossilized microscopic unicellular algae or aquatic plants comes in a various sizes ranging from very small, no larger than one micrometer in diameter, to one millimeter. It has delicate siliceous skeletons in its inner part composed of two cell walls, whose diameter normally is 10~200 micrometers. DE has a wide variety of forms: a shape like fine lace, a round or cylindrical form, or shapes such as a dish, ladder, plumage, needle and the likes. Sometimes, it features greatly varied forms displaying many void spaces, pores or tiny openings in a complex fashion. The cells are comprised mostly of amorphous silica, and sometimes also a little bit of crystalline silica.

It is also known as kieselguhr, which indicates impure DE highly containing clay and other minerals. In addition, moler designates Danish DE holding 20~25% calcined clay.

Because of the complex structure of DE ore itself, and its low density due to the primary and secondary pores or voids of floating algae, DE has frequently been used as an excellent filtration medium, filler, abrasive material, absorbent, building material and thermal insulator. Currently it has drawn attention not only as an environmentally friendly element, but as a material for solar cells and semiconductor wafers.