What is Diatomaceous Earth (DE)? Diatomaceous Earth, also known as kieselguhr or diatomite is simply the fossilized skeletal remains of millions of microscopic unicellular plants, diatoms, which lived in the ancient fresh and salt water bodies of the earth more than 5 million years ago.
Today there are still many diatom varieties that live in both freshwater lakes and salt water oceans, staying close to the surface of the water where they form part of the make-up of plankton. Alive, they are at the bottom of the food chain. Dead, they leave a tiny skeleton, measuring in microns, known as a frustule often of great beauty and intricacy.

All EP Minerals, Celatom diatomaceous earth filter aids are of the freshwater type and are predominantly (85-90%) of the species Melosira Granulata. This species is characterized by a natural, filter-like, cylindrical shape of great mechanical strength. During the late Tertiary Period, approximately 5 to 20 million years ago, massive deposits of skeletal remains were formed in the freshwater lakes which covered much of what is now Nevada and Eastern Oregon. Geological upheavals over the eons have exposed these abundantly rich deposits, which can be as much as several hundred feet thick or as little as a few inches, depending on the climate in which they lived.

Diatomite also grows differently than most plants. Most plants utilize solar energy to synthesize cellulose for their cell walls whereas diatoms extract amorphous silica from the water, building for itself a strong, pure and stable shell. This natural structure is ideal for applications demanding performance and purity, such as those found in the brewing, food and beverage and pharmaceutical applications.

Where does DE come from?
EP Minerals, Celatom diatomite is surface mined from our mines located in Nevada and Oregon. Each of our mines are freshwater diatoms and are almost strictly Melosira Granulata. This consistency in our ore deposits allows us to supply customers with identical filter aid products from either of our processing plants which insures consistent and reliable filtration performance.

How is filter media made from DE?
The production of diatomite filter aids is delicate and complicated. It requires large processing facilities and heavy earth moving equipment. EP Minerals operates three facilities for the production of diatomite filter media, two in Nevada and one in eastern Oregon.

The ore is first surface mined. To get access to the ore a considerable thickness of earth may have to removed, known as overburden. When this layer is removed and the purest of the diatomite strata is exposed, it is then cut from the bed with powerful scrapers and stockpiled.

The stockpiled material is then hauled to the processing plant where it is offloaded into an automated crusher and conveying unit. Going into the machine the pieces may be as large as a small car, but coming out they will be the size of a pea. The crushed ore is then elevated to storage bins of sufficient capacity to feed the plant for nearly continuous processing, 7 days a week, 24 hours a day.

At this point the ore in the storage bins will still contains moisture. In order to dry the ore, significant amounts of heat must be applied in flash dryers. The ore is then milled gently to preserve the structure of the DE which gives Celatom DE its remarkable properties. In order to provide the quality that our customers have grown to expect it is critical that the ore be completely pure. A small amount of foreign matter can greatly downgrade the filter medias’ performance and jeopardize our clients processes and products. These impurities are removed via a series of separators and traps.

The ore is then classified and sent to a large rotary kiln, where it is calcined (heated) to agglomerate the diatoms and produce the desired grade. This is a highly energy intensive process. The ore is heated to temperatures in excess of 1800 degrees Fahrenheit for up to one hour. After calcination the DE is light pink in color. A fluxing agent is also sometimes added to the kiln in order to agglomerate the diatoms even further. This is done to achieve the high flow rates of our fast white grades. After calcination the product is once more milled and classified before it is packaged and delivered to our customers.