Diatomite

Diatomite is a powdery, non-metallic mineral composed of the fossilised skeletal remains of microscopic single-celled aquatic plants called diatoms. Over 10,000 species of these microscopic algae have been recognised, each with its own distinct shape, ranging in size from under 5 microns to over 100 microns. Diatomite deposits are usually categorised based upon their fresh water or salt water origin. Both the chemical composition and the physical structure of diatomite make it of great commercial value for a wide spectrum of uses, including filter aids, functional fillers, carriers for active ingredients and diluents, and aggregates. Diatoms have the unique ability to absorb water-soluble silica present in their natural environment to form a highly porous, yet rigid, skeletal framework of amorphous silica. To this day, living diatoms in bodies of water worldwide continue to serve as a source of food for marine animals and, by photosynthesis, as a major source of atmospheric oxygen. Over the eons, their remains settled and were joined by succeeding generations forming deep-bedded deposits on ocean and lake floors, some of which rose about fifteen million years ago to become part of our present land-mass. In a few regions the diatomite deposits formed in sufficient thickness and purity to be mined for many uses beneficial to mankind. Before the end of the 19th century, the diatomite deposits attracted attention as a potential industrial material. At that time the chemical and physical properties of diatomite as an insulation material were already recognised. It was not, however, until sometime later, that the mining and processing of diatomite could be called an industry with a predictable future. The unique properties of diatomite including: Light weight High porosity High absorptivity High purity Multi-shaped Rigidity Inertness make it industrially useful in a variety of ways such as in liquid filtration; as a multi-functional mineral additive; as a carrier for active ingredients and diluents; as an aggregate; and, as a source of silica to name just a few. During its early development period, diatomite was processed almost exclusively by hand. It was taken from the beds in blocks and dried, and subsequently shipped in this form. The first mill or plant for processing natural diatomite was constructed in the early 1900s. Today, diatomite is typically mined by open-pit quarrying techniques using conventional, heavy duty earth moving equipment then transferred to a processing plant. At the plant, three different processes are used to manufacture the many different diatomite products depending on the desired characteristics.