Diatomaceous earth: characteristics, types and applications

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When the algae die, all organic components are destroyed except for the silica skeleton which settles to the bottom of the water. Over time, it forms huge deposits of fossilized algae called diatomaceous earth, a material that is therefore inert and non-toxic. When the soil is mined, crushed, finely ground, sieved and centrifuged, it becomes a refined talc that is safe to handle.


Diatomaceous earth: what is it?

Diatomaceous earth is the material resulting from the fossilization of unicellular algae coated with a bed of silica. These algae are called Diatomites and have an exoskeleton of mineral origin. Like all organisms, plants or animals, algae also feed and in this case they fed on silica to then transform it into organic silica. Diatomites have an amorphous structure and are found inland due to their occupation millions of years ago when lakes and seas covered the planet.

Diatomaceous earth: characteristics

Diatomaceous earth is a sedimentary rock composed of the prehistoric skeletal remains of single-celled aquatic plants called diatoms. Most are fossilized and were deposited in the Miocene, around 15 million years ago. Some deposits come from salt water, but most come from fresh water sources. The profusion of shapes results in an extremely low density diatomaceous earth powder with excellent filtration characteristics.

Diatomaceous earth: types

There are two types diatomaceous earthcalcined and food grade (biological).

The first is mainly used for industrial applications (water filtration, liquid absorption…) and the second is of great importance in the agricultural sector.

  • Calcined Diatomaceous Earth: This land is dangerous for us and our animals, especially if used for long periods of time and without adequate safety measures. As the name suggests, calcined diatomaceous earth has been exposed to high temperatures. Heating (combustion) converts the amorphous silica surrounding the algae into crystalline silica. A material that cannot be manipulated by living organisms and, therefore, can be dangerous with continuous use (regular contact silicosis) and without adequate protection (gloves, masks, etc., goggles).
  • Food grade diatomaceous earth: unlike calcination, it does not undergo any change in composition, its structure therefore remains amorphous, that is to say non-crystalline. Therefore, it is not harmful to humans, plants or animals. The silicone in it is processed by the seaweed itself, so we had no problems handling it and using it. Diatomaceous earth is not insect resistant, that is, unlike other insect resistant insecticides, diatomaceous earth kills insects at the root, but it is not resistant to their constituents. What this product does is it clings to the insect and kills it by absorbing all the water in it.

Diatomaceous earth: applications

  • Filtration😀Given its high porosity, diatomaceous earth is the most used (65 to 70%) as a filter medium, especially for swimming pools. It is a filtration aid in chemistry, to separate very fine particles that would otherwise pass through or clog the filter paper. It is also used to filter water, especially in the drinking water treatment process, and other liquids, such as beer. It can also filter syrups and sugar. Other industries such as paper, paints, ceramics, soaps and detergents use it as filler material.
  • Abrasive– Diatomaceous earth’s oldest use is as a mild abrasive. This application includes its use in toothpastes, metal polishes and some facial scrubs.
  • Insect control: The fine powder absorbs lipids from the cuticle (the waxy outer layer of insect exoskeletons), causing them to dehydrate. The decrease in water pressure kills arthropods. This approach also works against gastropods and is commonly used to defeat garden snails. It is sometimes mixed with an attractant or other additives to increase its effectiveness. Medical grade diatomite is sometimes used to deworm animals and humans. It is also used to help control and possibly eliminate a cockroach infestation.

  • Absorbent: Was used as a primary ingredient in a type of cat litter. The type of silica used in cat litter comes from freshwater sources and does not pose a significant health risk to pets or humans. In 1867, Alfred Nobel discovered that nitroglycerin (an explosive) could be made much more stable if absorbed in diatomaceous earth. He patented this mixture as dynamite, also known as gum guhr dynamite.
  • Heat resistance: Due to its heat resistance, diatomaceous earth can be used as a barrier material in some fire safes.
  • hydroponics: Freshwater diatomaceous earth can be used as a growing medium in hydroponic gardens.

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