Updated: Sep 2, 2020
Diatomaceous earth also known as D.E., diatomite, or kieselgur – is a naturally occurring, soft, siliceous sedimentary rock that is easily crumbled into a fine white to off-white powder.
It has a particle size ranging from less than 3 μm to more than 1 mm, but typically 10 to 200 μm. Depending on the granularity, this powder can have an abrasive feel, similar to pumice powder, and has a low density as a result of its high porosity. The typical chemical composition of oven-dried diatomaceous earth is 80–90% silica, with 2–4% alumina (attributed mostly to clay minerals) and 0.5–2% iron oxide.
Diatomaceous earth consists of fossilized remains of diatoms, a type of hard-shelled protist.
How to convert the powder form into a good free flowing liquid?
To help improve the handling of the product the following recommendation can be applied to produce a nice liquid dispersion with good stability.
Add water, Lansperse, HEC and biocide and mix using a high shear homogeniser for 10 mins at 3000 rpm
Then slowly over 5 mins add the Diatomaceous earth
Then finally mix for a further 20 mins
The product then produces a nice pourable stable dispersion with a viscosity around 300 centipoise.
Coatings – Matting Agent
In paint, diatomaceous earth fillers are used as a flattening agent. Diatomaceous earth alters gloss and sheen, extends primary pigments, adds bulk and strength, and enhances coating adhesion. It can also be added as a whitening agent and extender where titanium dioxide must be minimized.
Cement & Concrete
Diatomaceous earth is well-known for being a supplementary cementing material in concrete mixes and as an admixture for improving concrete properties, including:
Better concrete hydration and curing
Improved resistance to freeze/thaw cycles
Improved corrosion resistance
Better water resistance
Natural diatomaceous earth is inert, retains water, and has a high porosity that allows the soil to breathe. These qualities and more make it an efficient tool for horticulturists
Key Benefits of Diatomaceous Earth as a Soil Amendment
Increased plant health
Natural insect control
Reduced abiotic and biotic plant stress