Difference between sand and dropout.

Sand and screening refers to bulk materials used in construction. To an uninformed person, they may seem the same at first glance, but there is a difference between them. What is the difference between sand and screening, and what is the scope of both? Consider below.

What is sand and what is screening?

Sand is a sedimentary rock composed of quartz grains (most often). The grain size is no more than 5 millimeters. Sand is mined in quarries or on river banks, and natural or artificial flushing with water removes dust particles and foreign inclusions (for example, clay) from it. Experts distinguish between several types of sand - according to the degree of purification, according to the size of the grains, according to the material of the rock.

Sand is used for the production of concrete and products from it:

• blocks;
• well rings;
• tubing;
• reinforced concrete trusses, etc.

In addition, sand is used in the production of paving slabs, in the construction of embankments, in the construction of roads, bridges, hydraulic structures, for sandblasting and much more. Painted sand has found application in landscape design.

Screenings, like sand, have a grain size of no more than 5 millimeters (in most cases), but it is not a sedimentary rock, but the product of crushing factories of stone quarries. In professional language, screening is called "crushed stone of fraction 0-5". This is the main difference between screening and sand. Here, perhaps, it is worth making a digression and explaining something. At the quarry, after crushing the stone, it is sorted; for this, aggregates called "screens" are used. They are vibrating inclined gratings, along which large pieces of stone roll onto a conveyor, and small pieces fall into cells and are piled into heaps. Everything that falls into the cells measuring 5 by 5 millimeters is screening out.

The fundamental difference between sand and screening is in the presence of a large number of very small particles in the latter. Therefore, there is always a cloud of dust in the sorting points during operation. Screening is in demand in the production of asphalt concrete, mortars and in landscape design. It can be used in the production of paving slabs and some grades of concrete, but most often in these cases, sand is still used. The most valuable screening is granite (due to the strength of the material). Other species - for example, screening from porphyrite - are of less importance.

Comparison

It is clear that if the production of screening requires a whole range of different operations, machines and assemblies (blasting, crushers, screens), then its cost is much higher than the cost of sand, which most often they are simply scooped from a quarry with an excavator. Indeed, sand is sold at prices several times less than crushed stone. Interestingly, when selling crushed stone, such a concept as "bulk weight" is used. This means that a cubic meter of screening (fraction 0-5, where the grains are located close to each other and fill the volume as much as possible) will weigh more than a cubic meter of fraction 60-100, where there will be a lot of free space between the grains (in fact, cobblestones). The bulk density of sand and screenings is almost the same. Well, perhaps now we have completely figured out what is the difference between sand and screening.

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