15 Sieving Examples - encyclopedia

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Sieving Examples
Other techniques for separating mixtures

The sifted, screening or cast is a useful phase separation method to distinguish between two solid substances whose particles are of different sizes.

For this it uses a sieve, sieve or strainer, which is nothing other than a network of some resistant substance whose openings or pores allow the passage of matter smaller in size, retaining instead that of larger particles.

It is a simple and widely used method to separate heterogeneous mixtures solid compounds, whatever their nature. Sieves can have various shapes, thicknesses and porosities.

Sieving Examples

Sifting the flour. In the kitchen the flour is usually sifted to aerate it and homogenize it, preventing it from forming lumps once mixed with other substances.
Mineral salt separation. To distinguish between salt of mineral origin and the frequent residues of rock or other substances, a sieve is used that retains most of the residues and lets the much finer salt pass.
Rock removal on the ground. If dry soil from the soil is passed through a sieve, it will retain rocks and other debris, letting pure soil particles pass instead.
The salt in the popcorn. Popcorn, popcorn or popcorn tend to be rich in salt when we buy them at the movies. A solution to reduce the concentration of the same is to shake the paper bag, so that the salt falls through the holes in the corners and the corn remains. In that case, the paper acts as a sort of sieve.
Sifting the rice. Often a strainer is used to sift the rice or other grains just taken out of their bag, to separate the valuable grains from the stones, impurities and broken grains, which, being smaller, pass through the strainer, leaving what is desired inside.
Wheat separation. In the wheat flour production process, it is sifted in various mills to separate it from the bran or bran (the husk of the grain).
Homogenization of the sand. This procedure is carried out in the construction sector, to standardize the size of the sand particles, which can often agglutinate in larger structures. It is made to pass through a sieve and thus everything remains the same size.
Sprinkled in pastry. Cinnamon, chocolate or other frequent companions in confectionery are usually sifted through a strainer when spreading them on the surface of the dessert, to allow a more homogeneous distribution and to prevent them from remaining voluminous.
Composting. This method of recycling organic matter often benefits from simple screening, to extract from the organic mixture reintroduced to the soil those plastic, metallic or hard particles that could contaminate it. The organic matter is so ductile that it passes through the sieve, while the rigid elements remain in the weft.
Salt and pepper shakers. The lid of these devices, which is perforated, operates like a sieve, retaining inside the container most of the material (salt or pepper), as well as possible lumps of it that have formed (some salt shakers are even put rice inside), or simply slowing its flow to food.

Sifting in Mining. In obtaining gold and other precious metals, certain types of sieve are usually used to separate the precious mineral from sand or earth, usually previously moistened.
Coffee making. To separate the grain from the remains of leaves, sticks or other materials that accompany the coffee berry in its process, a form of sieve is used.
Cleaning the cat's litter box. It is done through a small rake-shaped sieve, which lets the sand pass but retains the animal's feces.
Cement screening. Since it is such a desiccant material, cement tends to collect humidity from the environment, forming small lumps like stones. It is then that it is sifted before using it in the elaboration of a construction mixture.
Seed separation. In the seed industry, seeds must often be screened to distinguish them from impurities added during processing and from animals that just feed on them.