Grades of Diatomaceous Earth and their uses
Author: Tony Date Posted:5 January 2016
Diatomite is comprised mostly of the skeletal fossils of diatoms and classified as a siliceous sedimentary rock. Diatoms are aquatic algae related single celled organisms which are porous in structure. For this reason diatomites are most commonly used as a filtration material.
It is not chemically reactive and looks much like chalk while dry; however, it is a great deal lighter. The purposes of diatomaceous earth date at least as far back as 15 CE in Greece when it was used in brick making and pottery.
Deposits of diatomite have been found all over the world; however, those that are pure and viable for marketing uses are the exception to the rule. The uses of this inert substance are extremely wide ranging which include the processing of thousands of products and the actual production hundreds. Some of the characteristics of diatomite which render it marketable are listed below.
- DE has insulating qualities.
- It offers abrasive attributes.
- DE is extremely porous.
- It has a high silica content.
- DE possesses a high capacity for absorption.
- It offers a large degree of surface area.
- The density level of DE is low.
- DE is chemically unreactive.
Amorphous Silica vs Crystalline Silica
Diatomaceous earth may first be divided into non-calcined and calcined. The differences in these are the essential variable which determines the purpose of each. DE that has been heat treated with temperatures in excess of 800 ºC. This process is necessary to produce a more effective filtration agent. The heat is a catalyst which transforms amorphous silica into crystalline silica.
This form should not be used for any type of consumption as the crystalline silica can cause toxicity in humans and animals. It should not be used for food storage purposes or inhaled. This form is often referred to as pool grade DE.
The non-calcined form of diatomaceous earth is natural and is not treated with heat of intense temperatures or chemicals. Amorphous silica is not considered to be hazardous to the health of humans or animals. In order to be labelled as food grade the crystalline silica content must be under 1%. Those which are calcined may carry a crystalline silica content as high as 70%.
Freshwater vs Saltwater
One of the most significant uses of superior quality diatomite is as a filtration media for the production of wine and beer as well as the manufacturing of pharmaceuticals. The structure of the fossils resembles that of a microscopic honeycomb lends the effective filtration properties. Pool grade diatomaceous earth in mined from ancient saltwater beds while the food grade version is derived from dry primordial freshwater beds.
DE: Industrial Uses
- Today DE is used in manufacturing personal hygiene products such as toothpaste, facial cleansers, exfoliators, and numerous powder based cosmetics.
- It is used to create filters for pools and aquariums as well as wineries and breweries.
- Diatomaceous earth is used in processing motor oil and the manufacture of pharmaceuticals.
- It is used to alter the sheen and gloss of paint as well as increases strength and bulk. DE also enhances the adhesion of coatings and regulates permeability.
- Diatomaceous earth is used in the production of plastics as an anti-blocking agent. For instance this is what makes plastic bags slide easily from the package instead of sticking together.
- It is used to absorb spills in several types of industrial setting such as waste treatment facilities, automobile manufacturers, and janitorial services.
- Diatomaceous earth is add to soil to increase the permeation of air and water as well as decrease compaction. It serves as an amendment to loosen compacted soil, increase drainage, and promote root growth.
- Areas with a high level of controlled landscape such as golf courses employ DE to absorb and retain water thereby decreasing the quantity of water required.
- It is extremely abrasive and can puncture the waxy exoskeletons of insects and its absorption capacity drains them causing death by dehydration. It is not possible for pests to build an immunity to its effects. As an insecticide diatomaceous earth is effective in both residential and commercial settings.
- Diatomaceous earth is used in agricultural settings as an insecticide for gardens and structural treatments of grain storage.
There are many other uses of DE that most never realize such as to coat seeds, create paper, make specific types of concrete, and for dental fillings. The oil industry uses it as a thickener compound for drilling. Diatomaceous earth has also found a place in the production of sealants, roofing compounds, and adhesives.
Diatomaceous Earth at Home
While DE has been around and used for perhaps thousands of years it has only recently reach popularity on the consumer market. Individuals all over the world purchase diatomaceous earth to use for many purposes in the home, yard, barn, and yard. It has become widely available both in brick and mortar shops as well as online.
- Diatomaceous earth is an effective method to rid homes of annoying pests such as cockroaches, fleas, beetles, and bedbugs. It is excellent for use in the garden and barn as well.
- DE is a great odour eliminator to use in litter boxes, refrigerators, and carpets.
- Many pet parents use it to eradicate fleas and ticks from pets.
- For those who keep a well-stocked pantry can use it to store dry goods and protect them from weevils.
- Diatomaceous earth works well as a soil amendment and insecticide in home gardens.
- It soaks up spills in garages and home workshops.
- DE is an effective as a household cleaner due to its abrasiveness. It may be used as a metal polish or to scrub tough stains.
Note: Only food grade diatomaceous earth is natural as it is not heat or chemically treated. It alone should be used for purposes in which there is risk of direct exposure. Pool grade DE is not only ineffective for destroying insects, it can also be a health hazard. It is important to purchase food grade diatomaceous earth from reputable sources.